Review ArticleLong Noncoding RNAs as Novel Biomarkers Havea Promising Future in Cancer Diagnostics

Ting Shi Ge Gao and Yingli Cao

Faculty of Laboratory Medicine Xiangya Medical College Central South University Changsha Hunan 41001 China

Correspondence should be addressed to Ge Gao ggboxy163com

Received 3 December 2015 Revised 14 March 2016 Accepted 16 March 2016

Academic Editor Lance A Liotta

Copyright copy 2016 Ting Shi et alThis is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Cancers have a high mortality rate due to lack of suitable specific early diagnosis tumor biomarkers Emerging evidence isaccumulating that lncRNAs (long noncoding RNAs) are involved in tumorigenesis tumor cells proliferation invasion migrationapoptosis and angiogenesis Furthermore extracellular lncRNAs can circulate in body fluids they can be detected and stronglyresist RNases Many researchers have found that lncRNAs could be good candidates for tumor biomarkers and possessed highspecificity high sensitivity and noninvasive characteristics In this review we summarize the detection methods and possiblesources of circulating lncRNAs and outline the biological functions and expression level of the most significant lncRNAs in tissuescell lines and body fluids (whole blood plasma urine gastric juice and saliva) of different kinds of tumors We evaluate thediagnostic performance of lncRNAs as tumor biomarkers However the biological functions and the mechanisms of circulatinglncRNAs secretion have not been fully understoodThe uniform normalization protocol of sample collection lncRNAs extractionendogenous control selection quality assessment and quantitative data analysis has not been establishedTherefore we put forwardsome recommendations that might be investigated in the future if we want to adopt lncRNAs in clinical practice

1 Introduction

The human genome is composed of large and complexnucleotide sequences which can produce more than 100000proteins through transcription and translation Only 2 ofgenomic transcripts have protein-coding ability the remain-ing 98 do not have protein encoding function [1] butexert an enormous function on the process of cell biologythese kinds of RNAs are called ncRNAs (noncoding RNAs)ncRNAs are divided into short noncoding RNAs (20ndash200 nt)and long noncoding RNAs (200 ntndash10 kb) lncRNAs accountfor more than 80 of ncRNAs [2 3] In recent yearsncRNAs have attracted increasing attention of researchersas they have found ncRNAs play a crucial role in regulatinggenes transcription process miRNAs as a member of shortnoncoding RNAs participate in cellular process throughtargeting hundreds of mRNAs and they serve as oncogenesor tumor suppressor genes in cancer to promote or inhibitthe initiation and progression of cancer [4] Furthermorethey can be detected in body fluids such as blood urine

breast milk cerebrospinal fluids and bronchial lavage [5ndash7] which endow them with the potential to be developedas tumor biomarkers and contribute to diagnosis prognosisand classification of cancers [8 9] However there are noconsistent results between the studies that deem the microR-NAs as biomarkers [10] Therefore seeking alternative andcomplementary biomarkers is urgently needed

Concerning the potential of being tumor biomarkersof miRNAs and the proportion of lncRNAs in ncRNAresearchers speculated lncRNAs may be promising alterna-tives and then transferred their focus on lncRNAswhichwerepreviously regarded as junk genes Mercer et al [11] found theexpression of lncRNAs had temporal and tissue specificityThe genes coding lncRNAs either overlap with protein-coding and noncoding genes or are scattered between themThis kind of localization is beneficial for them to regulatethe transcription of adjacent genes [12] Ectopic expressionof lncRNAs is responsible for tumorigenesis Firstly lncRNAsregulate some oncogenes and tumor suppressor genes bothat transcriptional and posttranscriptional levels ultimately

Hindawi Publishing CorporationDisease MarkersVolume 2016 Article ID 9085195 10 pageshttpdxdoiorg10115520169085195

2 Disease Markers

affecting the proliferation apoptosis invasion migrationand metastasis of tumor cells [13 14] Secondly lncRNAsregulate chromatin remodeling and are essential to theintegrity of nuclear structure [15] Thirdly lncRNAs can alsoinduce epithelial-to-mesenchymal transition (EMT) via thePI3K-AKT and Wnt120573-catenin pathway [16 17] to promotecancer metastasis Although the concrete functional roles oflncRNAs in cancer are unclear we are positive about theirfuture applications in human tumors

Despite ribonucleases abundantly existing in body fluidsresearchers have found lncRNAs could be detected andcould resist ribonucleases degradation activities Detection ofcirculating lncRNAs in body fluids can be a novel noninvasivemethod and can be used in the assessment of cancersat the following aspects (1) distinguishing tumor patientsfrom healthy people at early stage with high sensitivity andspecificity (2) predicting the prognosis of tumor patients (3)predicting the risk of tumormetastasis and tumor recurrenceafter surgical operation (4) as an assessment index to evaluatewhether operation is successful or not Above all utilizing cir-culating lncRNAs as tumor biomarkers has vital significancesfor clinical research

2 Detection Methods and Sources ofCirculating lncRNAs

The stability of lncRNAs in body fluids of tumor patientshas been explored in limited studies Some researchershave found lncRNAs remained stable in plasma even underoppressive conditions such as multiple cycles of freeze-thawincubation at 45∘C for 24 hours and incubation at roomtemperature for up to 24 h [18] To choose the suitablevacutainer tubes to collect specimens Ren et al [19] com-pared the level of lncRNAs among heparin plasma EDTAplasma and serum They found EDTA plasma and serumboth maintained the stability of lncRNAs effectively whereasthe expression level of lncRNAs in heparin plasma had asignificant decline Thus we can use EDTA vacutainer tubesor the tube without anticoagulant to collect blood specimenfor analyzing the expression of plasma lncRNAs

Regarding the detectionmethod of lncRNAs quantitativereal-time PCR is considered to be the gold standard forquantitative expression analysis of lncRNAs However inthe aspects of extraction methods and kits endogenouscontrols and quantification methods there exists no unifiedstandard Quantification methods are divided into relativequantification and absolute quantification methods In rel-ative quantification methods the levels of lncRNAs aredetermined by theΔΔCTmethod In order to produce reliableresults the endogenous controls for normalization should bechosen correctly and should be tested prior to applicationWeber et al [20] measured the potential reference genesGADPH HRPT1 and RPLP0 in NSCLC patients and normalcontrols RPLP0 was excluded from the reference genesdue to its different expression between NSCLC patients andnormal controls Although RPLP0 is a suitable reference genefor analyses in NSCLC tissues [21] it is not feasible as anendogenous control in human blood Considering that there

has been no consensus on the stable and suitable endoge-nous controls some researchers used absolute quantificationmethod and the level of lncRNAs is determined by thestandard curve constructed with reference standards [22]

The molecule mechanisms underlying circulating lncR-NAs secretion and transport to the extracellular environmenthave not been clear and have been only elucidated in a fewstudies Some researchers speculated the secretion of lncR-NAs may be in the same manner as miRNA According tothe relevant studies lncRNAsmay secrete in threemanners asshown in Figure 1 (1) extracellular RNAs package themselvesinto membrane vesicles to secrete and resist RNase suchas exosomes and microvesicles Exosomes and microvesiclesare 50 to 100 nm long in diameter lipoprotein vesicles andare formed by inward budding of multivesicular bodies(MVBs) through the endocytic pathway Then through thefusion of MVBs with plasma membrane exosomes secretedconsistently [23] Initially exosomes seemed as discardedmembrane proteins without any biological functions [24]However more recent studies have shown that exosomesand microvesicles that encapsulate both RNA and proteinscan be messengers to transfer information via regulatingtranscription and translation processes Huang et al [25]did a deep-sequence to characterize human plasma-derivedexosomal RNAs and finally detected that lncRNAs accountedfor 336 of all exosomal RNAs sequences Another studyshowed that there were no significant differences of lncRNAlevels in plasma and exosomes These results indicatedlncRNAs mainly exist in exosomes and exosomes are themain protector for plasma lncRNAs [26] (2) ExtracellularRNAs are released by tumor tissues and cells Ren et al [19]identified lncRNA levels drastically increased in plasma dueto the presence of subcutaneous xenograft cancer Moreoverthe expression level of plasma lncRNAs was decreased fromthe preoperative patients to the postoperative patients Thissuggested lncRNAs were derived from the tumor cells andcould enter the circulation Besides circulating and primarytumor cells circulating lncRNAs have multiple sources suchas cancer-adjacent normal cells immune cells and otherblood cells [18 26] (3) Extracellular RNAs encapsulatethemselves into high density lipoprotein (HDL) or apoptosisbodies or associatedwith protein complexesThemost typicalprotein complexes are Argonaute- (Ago-) miRNA complex[27] and nucleophosmin 1- (NPM1-) miRNA complex [28]

The biological functions of circulating lncRNAs and thepossibility of lncRNAs becoming disease-specific noninva-sion biomarkers are poorly understood The mechanismsregulating circulating lncRNAs expression remain unclearhowever if we want to find out the relationship betweencirculating lncRNAs expression level and cancers we mustbreak through these issues in the future

3 MALAT1 in Cancer TissuesCell Lines and Body Fluids

31 Lung Cancer (LC) Metastasis-associated lung adeno-carcinoma transcript 1 (MALAT1) was first studied in themetastatic lung adenocarcinoma patients In order to find

Disease Markers 3

Tumor cell Normal cell

AGO2

NPM1

Apoptotic bodyHDL

Dendritic cell Epithelial cellsT-cellB-cell

Exosomes

Microvesicles

MVBs

Blood vessel

Circulating lncRNAs

Membrane fusion Outward budding

Major carriers of circulating lncRNAs

Secrete

Figure 1 The origin of circulating lncRNAs and several manners of circulating lncRNAs encapsulation

which genes are associated with LC metastasis Ji et al [29]utilized subtractive hybridizationmethod to analyze differentgene expressions between metastatic and nonmetastatic lungtumor tissues They identified MALAT1 expressed threefoldhigher in metastatic tumor tissues In the early stage ofnon-small cell lung cancer (NSCLC) patients with highexpression level of MALAT1 had a high risk of subsequentmetastasis and poor prognostic Schmidt et al [30] studiedthe biological function of MALAT1 at a cellular level whichfound high MALAT1 expression in mouse fibroblast cellline (NIH3T3) increased its migratory and invasive capacitywhile low MALAT1 expression in A549 cell line impaired itsformation and growth To further elucidate the mechanismof MALAT1 getting involved in metastatic process Tanoet al [31] knocked down MALAT1 by short-interferingRNA (siRNA) in A549 cells simultaneously observing somemotility-associated genes such as CTHRC1 (collagen triplehelix repeat containing) CCT4 (chaperonin-containing tail-less complex polypeptide subunit 4) and ROD1 (regulatorof differentiation 1) Expression levels were downregulated atthemRNA level whereasAIM1 (melanoma 1) LAYN (layilin)and HMMR (hyaluronan-mediated motility receptor) werereduced at both pre-mRNA and mature mRNA levels ThissuggestedMALAT1modulated genes expression at transcrip-tional and posttranscriptional levels except for regulatingsplicing to enhance cell migrationMoreover MALAT1 couldbe involved in EMT process to promote tumor metastasis[32] Gutschner et al [33] utilized Zinc Finger Nucleases(ZFN) to build loss of function cells After injection ofMALAT1 knock-out cells in the nude mice the number oftumor nodules was reduced Furthermore tumor volume

and tumor weight decreased after treatment with MALAT1antisense oligonucleotides (ASO) All these indicated thatMALAT1 could be an effective therapeutic target in lungcancer in the future

MALAT1 not only has a crucial significance in predictingmetastasis risk and may be a promising therapeutic target intreating lung cancer but also can be a diagnostic biomarkerdetectable in blood to screen lung cancer Guo et al [34]analyzed the expression level of MALAT1 in 105 lung cancerpatients and 65 healthy personsrsquo whole blood by quantitativepolymerase chain reaction (qPCR) Surprisingly LC patientshad lower expression of MALAT1 than healthy subjects inwhole blood which was contrary to the high expression ofMALAT1 in lung cancer tissues But one common thing in tis-sues andwhole bloodwas thatmetastatic lung cancer patientshad stronger expression ofMALAT1 than nonmetastatic lungcancer patients Furthermore compared with lymph nodeand pleura metastasis bone and brain metastasis had highexpression of MALAT1 In the cellular fraction of peripheralhuman blood MALAT1 as a biomarker of screening NSCLCexhibited low sensitivity of 56 and high specificity of 96which demonstratedMALAT1 cannot be an independent buta complementary biomarker to diagnose NSCLC [20]

32 Prostate Cancer (PCa) The expression level of MALAT1in PCa tissues was first investigated by Ren et al [35]They used RNA-seq method to analyze the expression oflncRNAs in 14 pairs of PCa and adjacent normal tissues Theresults showed MALAT1 was overexpressed in PCa tissuesand high expression of MALAT1 had close relationships withhigh Gleason score prostate specific antigen (PSA) and

4 Disease Markers

tumor-node-metastasis (TNM) stage Then they studied thebiological function of MALAT1 in PCa at a cellular level Invitro they silenced MALAT1 in prostate cell lines 22Rv1 andLNCaP that ultimately inhibited the migratory and invasivecapacity of cancer cells and made cell cycle be arrested inG0G1 phases [36] In vivo the growth of tumor xenograftsbecame slower andmetastatic rate was reduced after injectingMALAT1 knock-out cells in the nude mice Additionally thesurvival time of tumor mice was prolonged [36] Above allMALAT1 can be an interesting therapeutic target for PCa

Unlike the low expression of MALAT1 in the wholeblood of lung cancer patients the expression of MALAT1derived miniRNA (MDminiRNA) was elevated in plasma ofPCa patients which was consistent withMALAT1 expressionin PCa tissues PSA is a prostate-specific biomarker Asa diagnostic marker PSA alone could be very sensitivebut with low specificity which finally brings about lots ofunnecessary biopsies and repeated biopsies [37] Comparedto PSA MD miniRNA was more effective plasma-basedbiomarkers to diagnose PCa from non-PCa MD miniRNAwas also more effective at distinguishing positive prostatebiopsies and negative prostate biopsies (AUC0841) than PSA(AUC 0708) [19] MD miniRNA was very helpful to predictprostate biopsy outcome Furthermore combined PSA andMD miniRNA could improve the sensitivity and specificityof diagnosis [19] Besides plasma Wang et al [38] evaluatedthe diagnostic value of MALAT1 in urine They observedthat with the level of PSA in gray zone (4ndash10 ngmL) settingurinary MALAT1 score cut-off of 95 had higher sensitivityand specificity than the fPSA (percentage of free PSA)which is the conventional reliable index for PCs diagnosis[38] Furthermore using the probability threshold of 25more cancer could be detected and unnecessary and repeatedbiopsies could be avoided 302ndash465 in PSA 4ndash10 ngmLcohorts [38]

4 H19 in Cancer Tissues Cell Linesand Body Fluids

41 Gastric Cancer (GC) The lncRNA expression profile inGC was uncovered by Song et al [39] They recruited GCtissues and noncancerous tissues to do lncRNA microarrayanalysis which found the gene H19 expressed up to 891-foldhigher in GC tissues Initially H19 was considered as tumorsuppressor gene because of its role in inhibiting tumorigenic-ity [40 41] but recent researchers have identified that H19can play a role as an oncogene Li et al [42] have observedthat the proliferative invasive and migratory abilities of cellswere repressed after the knocking down of H19 whereasafter subcutaneously injecting SGC7901 cells in nude micewhich were transfected with H19 the rate of tumor growthtumor size tumor weight and the number of metastasisnodules were increasedThe concrete regulationmechanismsof H19 as an oncogene include regulating tumor suppressorgene p53 [43] and H19miRNAtumor suppressor gene axisYang et al [44] found the activity of p53 significantlydecreased when H19 and p53-responsive reporter plasmidswere cotransfected into AGS human gastric cell lines Zhuang

et al [45] transfected MGC803 cells with siRNA-H19 andmiR-675 mimics simultaneously and the overexpression ofmiR-675 restored siRNA-H19-induced inhibition In treatedAGS cells with pcDNA-H19 and anti-miR-675 anti-miR-675 rescues pcDNA-H19-induced promotion of GC cellproliferation These results demonstrated that H19 regulatedGC cells proliferation phenotype through miR675 Throughseveral algorithms researchers found miR-675 regulated cellproliferation of GC cells by targeting the tumor suppressiongene Runt Domain Transcription Factor 1 (RUNX1) andconsisted of the H19miR675RUNX1 axis pathway [45]Besides RUNX1 ISM1 is another target protein of H19 [42]All these molecules can be promising therapeutic targets ofGC

Based on the studies of H19 inGC tissue researchers wereinterested in whether H19 can apply in clinical practices asa novel noninvasion biomarker to screen gastric biomarkersZhou et al [22] selected 8 lncRNAs in which their aberrantexpression in GC tissue was previously found and validatedtheir expression in plasma They found that among 8lncRNAs HOTAIR (Homeobox protein transcript antisenseRNA) MALAT1 and H19 were highly expressed in GCplasma However another study found the opposite resultsthat HOTAIR and MALAT1 had no significant difference inexpression of patients and controls Moreover this researchidentified that MALAT1 was not so stable in the plasmawhich was contradicted by MD miniRNArsquos stability in PCaplasma even in a harsh environment [19] H19 is highlyexpressed in GC plasma and could serve as a promisingbiomarker of GC due to its high diagnostic power for detec-tion of GC (AUC 0838 specificity 729 sensitivity 829)H19 could also screen for early stage of GC (AUC 0877specificity 801 sensitivity 855) which wasmore effectivethan the conventional biomarkers such as carcinoembryonicantigen (CEA) and carbohydrate antigen 199 (CA199) [22]

5 HOTAIR in Cancer TissuesCell Lines and Body Fluids

51 Colorectal Cancer (CRC) HOTAIR had oncogenic prop-erties Its high expression in CRC tissues was closely relatedto vascular invasion histological differentiation and livermetastasis [46 47] Patients with high expression of HOTAIRwere more likely to have tumor recurrence and poor prog-nosis Furthermore Cai et al [48] did a meta-analysis whichincluded 748 patients from 8 studies to evaluate the associ-ation between HOTAIR expression levels and lymph nodemetastasis They identified that patients with high expressionof HOTAIR had a high incidence of lymph node metastasisThe mechanisms of HOTAIR regulating the initiation andprogression of CRC include relying on Polycomb RepressiveComplex (PRC) complex to silence tumor suppressor genesand being involved in EMT process HOTAIR gene is locatedon chromosome 12q1313 between the HoxC11 and HoxC12exons [49] it can reprogram chromatin organization bybindingwith PRCat 51015840 domain and lysergic acid diethylamide(LSD) at 31015840 domain in CRC [46 50] PRC complex silencestumor genes at the trimethylation of histone H3 lysine

Disease Markers 5

27 (H3K27) through a methylation process PRC complexcontains an enhancer of zeste homolog 2 (EZH2) SUZ12 andEED three subunits [51] Among the three subunits EZH2 isthe core enzyme inmethyl transfer process andEED regulatesthe specialty of EZH2 by binding to target RNA [52]Wu et al[47] identified that after knocking down HOTAIR in SW480and HT29 CRC cell lines E-cadherin as marker of epithelialcell was increased and mesenchymal cell marker vimentinwas decreasedMoreover themajor proteinaseMMP9 whichimpaired the motile ability of cells was inhibited All thesestudies indicated that HOTAIR could be an independentbiomarker for CRC diagnosis

Currently there is only one study that focused onwhetherthe expression level of HOTAIR in blood can serve asa potential marker for CRC prognostic [53] This studysimultaneously detected expression levels of HOTAIR in73 CRC tissues and 84 CRC bloods Surprisingly theirresults in CRC tissues contradicted other studies that showedthere were no significant differences between tumor tissuesand noncancerous tissues whereas in blood HOTAIR wasupregulated and expressed higher in left (descendent) colontumors compared with right (ascendant) colon tumors Fur-thermore expression of HOTAIR can predict the survivaltime of patients High expression of HOTAIR had high riskof death and was associated with poor prognosis Evaluatingprognostic power ofHOTAIR by ROC curve (AUC087)mdashitsspecificity was 67 and sensitivity was 925mdashdemonstratedHOTAIR can be a negative prognostic marker not only intumor tissues but also in blood

52 Oral Squamous Cell Cancer (OSCC) The lncRNAexpression profile in OSCC was first investigated by Gibbet al [54] In OSCC HOTAIR was overexpressed in tumortissues compared to normal tissues and its high expressionwas correlated to tumor size clinical stage lymphatic nodemetastasis and histological differentiation [55 56] By knock-ing down HOTAIR in Tca8113 OSCC cell line we foundcells were arrested in G0G1 phase and apoptosis processwas accelerated The proliferation rate of cell was reducedand the invasion and migration of cell were inhibited [5556] Moreover the enrichment of EZH2 and H3K27me3 wassignificantly decreased while the expression of E-cadherinsignificantly increased after knocking down HOTAIR [5758] Treating Tca8113 and TSCCA cells with siEZH2 andsiEZH2+siHOTAIR caused E-cadherin expression levels toincrease at both mRNA and protein levels These resultselucidated HOTAIR participating in EMT process throughinteracting with EZH2 and H3K27me3 at the E-cadherinpromoter [56] Therefore HOTAIR plays a critical role inthe development and progression of OSCC and can be apredictive marker as well as a new therapeutic target inOSCC

Tang et al [59] detected lncRNA in saliva of OSCCpatients 1mL salivary samples were collected from 9 OSCCpatients and the presence of lncRNA was examined byqPCR Ct lt 40 was considered to be positive Finallythey found MALAT1 was detected in all samples but had nosignificant difference inmetastatic and nonmetastatic tissues

while HOTAIR was detected only in 59 patients and thepatients with lymph node metastasis had higher expressionof HOTAIR in saliva All these suggest detecting lncRNA insaliva may provide clinics with a noninvasive and convenienttool to screen OSCC

6 LINC00152 in Cancer Tissues Cell Linesand Body Fluids

61 Gastric Cancer (GC) LINC00152 is located on chromo-some 2p112 and its transcript length is 828 nt There wereseveral studies that demonstrated a novel long intergenicnoncoding RNA (lincRNA) LINC00152 was overexpressedin GC tissues [60 61] Pang et al [60] detected the expressionlevels of LINC00152 in 71 pairs of GC and adjacent normaltissues They found LINC00152 had significantly higherexpression levels in GC patients and this high expressionlevel was correlated with tumor invasion Its diagnostic valuewas evaluated by ROC curve (AUC 0645 specificity 681sensitivity 625) In addition compared with the normalhuman epithelial cell line GES-1 LINC00152 expression wasalso higher in GC cell lines such as BGC-823 MGC-803 andSGC-7901 [60]

Consistent with the results in GC tissues LINC00152levels in plasma significantly increased in both advancedGC patients and early GC patients In addition comparedwith preoperative plasma samples the expression level ofLINC00152 was elevated in postoperative plasma samples[26] This result was opposite to other studies The authorspeculated that operationsmay stimulate cells to release lncR-NAs into the plasma Plasma LINC00152 diagnostic value(AUC 0675 specificity 852 sensitivity 481) was betterthan conventional markers such as CEA and CA199 [26]Therefore LINC00152 can be a novel blood-based biomarkerto apply in clinical practices to diagnose GC Besides plasmagastric juice can be used in another noninvasion method forscreening for GC [62] LINC00152 could also be detected ingastric juice and its expression level was higher in the patientswith GC than normal people [60] However the function ofLINC00152 in GC is still unclear and the sample size detectedin plasma was very small Therefore further study shouldinvestigate the function of LINC00152 and expand the samplesize

7 Conclusions and Perspectives

In this review the biological functions and diagnostic valueof lncRNAs are assessed in Table 1 The largest troublesomeproblem of the treatment of various cancer is the lackof the early diagnosis approaches Some kinds of cancerscould be completely cured if the patients are diagnosed atan early stage However conventional tumor markers suchas CEA CA199 and CA129 have low specificity or lowsensitivity which leads to clinical false negative rate andfalse positive rate increase Thus finding out more effectivemarkers is urgently needed lncRNAs were formerly regarded

6 Disease Markers

Table1Ab

errant

lncR

NAs

expressio

nin

vario

uscancers

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

MALA

T1NSC

LC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GADPH

qRT-PC

RNull

[29]

Tissue

Up

Qiagen

RNeasy

Micro

Kit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[30]

Celllines

(A549HTB

53

565758)

Up

TRIzolRe

agent

[2931]

(Invitro

gen)

QiagenR

Neasy

Micro

Kit[30]

GADPH

SYBR

-Green

qRT-PC

RNull

[29ndash

31]

Perip

heralw

holebloo

dDow

nAxyPrepBloo

dTo

talR

NAMiniprep

kit

GAPD

HqR

T-PC

RAU

C0718

[34]

Cellularfractionof

perip

heralhum

anbloo

dDow

nRibo

Pure

Bloo

dKit

(Life

Techno

logies)

GAPD

HHPR

T1TaqM

anAU

C079

specificity96

sensitivity56

[20]

MALA

T1PC

a

Tissue

Up

TRIzolRe

agent[19]

(Invitro

gen)

GAPD

H[35]

ACTB

[19]

SYBR

-Green

qRT-PC

RNull

[1935]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)

Inpu

tamou

ntStandard

curve

metho

dSY

BR-G

reen

qRT-PC

RAU

C0836

specificity848

sensitivity586

[19]

Urin

eUp

TRIzolRe

agent

(Invitro

gen)

PSA

SYBR

-Green

qRT-PC

RAU

C(0670

and

0742)

[38]

H19

GC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

R[39]

SYBR

-Green

qRT-PC

R[4244

]Null

[394244]

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[45]

Tissue

Up

RecoverA

llTo

tal

NucleicAc

idIsolation

Kit

ACTB

TaqM

anNull

[18]

Celllines

(AGSMGC-

803

SGC-

7901SMMC-

7721

HepG2Du145P

C-3

A549)

Updo

wn

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

RNull

[39]

Disease Markers 7

Table1Con

tinued

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

Celllines

(AGSMKN

45

MG-C

803SG

C7901

GES

-1)

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

[4244

]GAPD

H[45]

SYBR

-Green

qRT-PC

RNull

[4244

45]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)Re

lativ

etothelevel

ofplasmalncRN

AsTaqM

anAU

C064

0specificity58

sensitivity74

[18]

Plasma

Up

TRIzolRe

agent

(TaK

aRa)

Standard

curve

constructedwith

lncR

NAprob

esSY

BR-G

reen

qRT-PC

RAU

C0838

specificity729

sensitivity829

[22]

HOTA

IRCR

C

Tissue

Up

ISOGEN

(Nippo

nGene)Q

IAam

pDNA

Micro

Kit[46

]AllP

repDNARNA

Minikit[47]

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[4647]

Celllines

(HT2

9SW

480)

Up

AllP

repDNARNA

Minikit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[47]

Bloo

dUp

MirV

anaIsolatio

nKit

(Life

Techno

logies)

ACTB

GAPD

H

HPR

TPP

IAG

US

18SrRNA

TaqM

anAU

C0870

specificity925

sensitivity67

[53]

HOTA

IROSC

C

Tissue

Up

TRIzolRe

agent

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[555659]

Celllines

(TSC

CATca8113)

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[56]

Saliva

Up

TRIzol(In

vitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[59]

LINC0

0152

GC

Tissue

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Celllines

(AGSBG

C-823

MGC-

803SG

C-7901)

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Gastricjuice

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

RAU

C064

5specificity681

sensitivity625

[60]

Plasma

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

R

AUC0675

specificity852

sensitivity

481

[26]

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

2 Disease Markers

affecting the proliferation apoptosis invasion migrationand metastasis of tumor cells [13 14] Secondly lncRNAsregulate chromatin remodeling and are essential to theintegrity of nuclear structure [15] Thirdly lncRNAs can alsoinduce epithelial-to-mesenchymal transition (EMT) via thePI3K-AKT and Wnt120573-catenin pathway [16 17] to promotecancer metastasis Although the concrete functional roles oflncRNAs in cancer are unclear we are positive about theirfuture applications in human tumors

Despite ribonucleases abundantly existing in body fluidsresearchers have found lncRNAs could be detected andcould resist ribonucleases degradation activities Detection ofcirculating lncRNAs in body fluids can be a novel noninvasivemethod and can be used in the assessment of cancersat the following aspects (1) distinguishing tumor patientsfrom healthy people at early stage with high sensitivity andspecificity (2) predicting the prognosis of tumor patients (3)predicting the risk of tumormetastasis and tumor recurrenceafter surgical operation (4) as an assessment index to evaluatewhether operation is successful or not Above all utilizing cir-culating lncRNAs as tumor biomarkers has vital significancesfor clinical research

2 Detection Methods and Sources ofCirculating lncRNAs

The stability of lncRNAs in body fluids of tumor patientshas been explored in limited studies Some researchershave found lncRNAs remained stable in plasma even underoppressive conditions such as multiple cycles of freeze-thawincubation at 45∘C for 24 hours and incubation at roomtemperature for up to 24 h [18] To choose the suitablevacutainer tubes to collect specimens Ren et al [19] com-pared the level of lncRNAs among heparin plasma EDTAplasma and serum They found EDTA plasma and serumboth maintained the stability of lncRNAs effectively whereasthe expression level of lncRNAs in heparin plasma had asignificant decline Thus we can use EDTA vacutainer tubesor the tube without anticoagulant to collect blood specimenfor analyzing the expression of plasma lncRNAs

Regarding the detectionmethod of lncRNAs quantitativereal-time PCR is considered to be the gold standard forquantitative expression analysis of lncRNAs However inthe aspects of extraction methods and kits endogenouscontrols and quantification methods there exists no unifiedstandard Quantification methods are divided into relativequantification and absolute quantification methods In rel-ative quantification methods the levels of lncRNAs aredetermined by theΔΔCTmethod In order to produce reliableresults the endogenous controls for normalization should bechosen correctly and should be tested prior to applicationWeber et al [20] measured the potential reference genesGADPH HRPT1 and RPLP0 in NSCLC patients and normalcontrols RPLP0 was excluded from the reference genesdue to its different expression between NSCLC patients andnormal controls Although RPLP0 is a suitable reference genefor analyses in NSCLC tissues [21] it is not feasible as anendogenous control in human blood Considering that there

has been no consensus on the stable and suitable endoge-nous controls some researchers used absolute quantificationmethod and the level of lncRNAs is determined by thestandard curve constructed with reference standards [22]

The molecule mechanisms underlying circulating lncR-NAs secretion and transport to the extracellular environmenthave not been clear and have been only elucidated in a fewstudies Some researchers speculated the secretion of lncR-NAs may be in the same manner as miRNA According tothe relevant studies lncRNAsmay secrete in threemanners asshown in Figure 1 (1) extracellular RNAs package themselvesinto membrane vesicles to secrete and resist RNase suchas exosomes and microvesicles Exosomes and microvesiclesare 50 to 100 nm long in diameter lipoprotein vesicles andare formed by inward budding of multivesicular bodies(MVBs) through the endocytic pathway Then through thefusion of MVBs with plasma membrane exosomes secretedconsistently [23] Initially exosomes seemed as discardedmembrane proteins without any biological functions [24]However more recent studies have shown that exosomesand microvesicles that encapsulate both RNA and proteinscan be messengers to transfer information via regulatingtranscription and translation processes Huang et al [25]did a deep-sequence to characterize human plasma-derivedexosomal RNAs and finally detected that lncRNAs accountedfor 336 of all exosomal RNAs sequences Another studyshowed that there were no significant differences of lncRNAlevels in plasma and exosomes These results indicatedlncRNAs mainly exist in exosomes and exosomes are themain protector for plasma lncRNAs [26] (2) ExtracellularRNAs are released by tumor tissues and cells Ren et al [19]identified lncRNA levels drastically increased in plasma dueto the presence of subcutaneous xenograft cancer Moreoverthe expression level of plasma lncRNAs was decreased fromthe preoperative patients to the postoperative patients Thissuggested lncRNAs were derived from the tumor cells andcould enter the circulation Besides circulating and primarytumor cells circulating lncRNAs have multiple sources suchas cancer-adjacent normal cells immune cells and otherblood cells [18 26] (3) Extracellular RNAs encapsulatethemselves into high density lipoprotein (HDL) or apoptosisbodies or associatedwith protein complexesThemost typicalprotein complexes are Argonaute- (Ago-) miRNA complex[27] and nucleophosmin 1- (NPM1-) miRNA complex [28]

The biological functions of circulating lncRNAs and thepossibility of lncRNAs becoming disease-specific noninva-sion biomarkers are poorly understood The mechanismsregulating circulating lncRNAs expression remain unclearhowever if we want to find out the relationship betweencirculating lncRNAs expression level and cancers we mustbreak through these issues in the future

3 MALAT1 in Cancer TissuesCell Lines and Body Fluids

31 Lung Cancer (LC) Metastasis-associated lung adeno-carcinoma transcript 1 (MALAT1) was first studied in themetastatic lung adenocarcinoma patients In order to find

Disease Markers 3

Tumor cell Normal cell

AGO2

NPM1

Apoptotic bodyHDL

Dendritic cell Epithelial cellsT-cellB-cell

Exosomes

Microvesicles

MVBs

Blood vessel

Circulating lncRNAs

Membrane fusion Outward budding

Major carriers of circulating lncRNAs

Secrete

Figure 1 The origin of circulating lncRNAs and several manners of circulating lncRNAs encapsulation

which genes are associated with LC metastasis Ji et al [29]utilized subtractive hybridizationmethod to analyze differentgene expressions between metastatic and nonmetastatic lungtumor tissues They identified MALAT1 expressed threefoldhigher in metastatic tumor tissues In the early stage ofnon-small cell lung cancer (NSCLC) patients with highexpression level of MALAT1 had a high risk of subsequentmetastasis and poor prognostic Schmidt et al [30] studiedthe biological function of MALAT1 at a cellular level whichfound high MALAT1 expression in mouse fibroblast cellline (NIH3T3) increased its migratory and invasive capacitywhile low MALAT1 expression in A549 cell line impaired itsformation and growth To further elucidate the mechanismof MALAT1 getting involved in metastatic process Tanoet al [31] knocked down MALAT1 by short-interferingRNA (siRNA) in A549 cells simultaneously observing somemotility-associated genes such as CTHRC1 (collagen triplehelix repeat containing) CCT4 (chaperonin-containing tail-less complex polypeptide subunit 4) and ROD1 (regulatorof differentiation 1) Expression levels were downregulated atthemRNA level whereasAIM1 (melanoma 1) LAYN (layilin)and HMMR (hyaluronan-mediated motility receptor) werereduced at both pre-mRNA and mature mRNA levels ThissuggestedMALAT1modulated genes expression at transcrip-tional and posttranscriptional levels except for regulatingsplicing to enhance cell migrationMoreover MALAT1 couldbe involved in EMT process to promote tumor metastasis[32] Gutschner et al [33] utilized Zinc Finger Nucleases(ZFN) to build loss of function cells After injection ofMALAT1 knock-out cells in the nude mice the number oftumor nodules was reduced Furthermore tumor volume

and tumor weight decreased after treatment with MALAT1antisense oligonucleotides (ASO) All these indicated thatMALAT1 could be an effective therapeutic target in lungcancer in the future

MALAT1 not only has a crucial significance in predictingmetastasis risk and may be a promising therapeutic target intreating lung cancer but also can be a diagnostic biomarkerdetectable in blood to screen lung cancer Guo et al [34]analyzed the expression level of MALAT1 in 105 lung cancerpatients and 65 healthy personsrsquo whole blood by quantitativepolymerase chain reaction (qPCR) Surprisingly LC patientshad lower expression of MALAT1 than healthy subjects inwhole blood which was contrary to the high expression ofMALAT1 in lung cancer tissues But one common thing in tis-sues andwhole bloodwas thatmetastatic lung cancer patientshad stronger expression ofMALAT1 than nonmetastatic lungcancer patients Furthermore compared with lymph nodeand pleura metastasis bone and brain metastasis had highexpression of MALAT1 In the cellular fraction of peripheralhuman blood MALAT1 as a biomarker of screening NSCLCexhibited low sensitivity of 56 and high specificity of 96which demonstratedMALAT1 cannot be an independent buta complementary biomarker to diagnose NSCLC [20]

32 Prostate Cancer (PCa) The expression level of MALAT1in PCa tissues was first investigated by Ren et al [35]They used RNA-seq method to analyze the expression oflncRNAs in 14 pairs of PCa and adjacent normal tissues Theresults showed MALAT1 was overexpressed in PCa tissuesand high expression of MALAT1 had close relationships withhigh Gleason score prostate specific antigen (PSA) and

4 Disease Markers

tumor-node-metastasis (TNM) stage Then they studied thebiological function of MALAT1 in PCa at a cellular level Invitro they silenced MALAT1 in prostate cell lines 22Rv1 andLNCaP that ultimately inhibited the migratory and invasivecapacity of cancer cells and made cell cycle be arrested inG0G1 phases [36] In vivo the growth of tumor xenograftsbecame slower andmetastatic rate was reduced after injectingMALAT1 knock-out cells in the nude mice Additionally thesurvival time of tumor mice was prolonged [36] Above allMALAT1 can be an interesting therapeutic target for PCa

Unlike the low expression of MALAT1 in the wholeblood of lung cancer patients the expression of MALAT1derived miniRNA (MDminiRNA) was elevated in plasma ofPCa patients which was consistent withMALAT1 expressionin PCa tissues PSA is a prostate-specific biomarker Asa diagnostic marker PSA alone could be very sensitivebut with low specificity which finally brings about lots ofunnecessary biopsies and repeated biopsies [37] Comparedto PSA MD miniRNA was more effective plasma-basedbiomarkers to diagnose PCa from non-PCa MD miniRNAwas also more effective at distinguishing positive prostatebiopsies and negative prostate biopsies (AUC0841) than PSA(AUC 0708) [19] MD miniRNA was very helpful to predictprostate biopsy outcome Furthermore combined PSA andMD miniRNA could improve the sensitivity and specificityof diagnosis [19] Besides plasma Wang et al [38] evaluatedthe diagnostic value of MALAT1 in urine They observedthat with the level of PSA in gray zone (4ndash10 ngmL) settingurinary MALAT1 score cut-off of 95 had higher sensitivityand specificity than the fPSA (percentage of free PSA)which is the conventional reliable index for PCs diagnosis[38] Furthermore using the probability threshold of 25more cancer could be detected and unnecessary and repeatedbiopsies could be avoided 302ndash465 in PSA 4ndash10 ngmLcohorts [38]

4 H19 in Cancer Tissues Cell Linesand Body Fluids

41 Gastric Cancer (GC) The lncRNA expression profile inGC was uncovered by Song et al [39] They recruited GCtissues and noncancerous tissues to do lncRNA microarrayanalysis which found the gene H19 expressed up to 891-foldhigher in GC tissues Initially H19 was considered as tumorsuppressor gene because of its role in inhibiting tumorigenic-ity [40 41] but recent researchers have identified that H19can play a role as an oncogene Li et al [42] have observedthat the proliferative invasive and migratory abilities of cellswere repressed after the knocking down of H19 whereasafter subcutaneously injecting SGC7901 cells in nude micewhich were transfected with H19 the rate of tumor growthtumor size tumor weight and the number of metastasisnodules were increasedThe concrete regulationmechanismsof H19 as an oncogene include regulating tumor suppressorgene p53 [43] and H19miRNAtumor suppressor gene axisYang et al [44] found the activity of p53 significantlydecreased when H19 and p53-responsive reporter plasmidswere cotransfected into AGS human gastric cell lines Zhuang

et al [45] transfected MGC803 cells with siRNA-H19 andmiR-675 mimics simultaneously and the overexpression ofmiR-675 restored siRNA-H19-induced inhibition In treatedAGS cells with pcDNA-H19 and anti-miR-675 anti-miR-675 rescues pcDNA-H19-induced promotion of GC cellproliferation These results demonstrated that H19 regulatedGC cells proliferation phenotype through miR675 Throughseveral algorithms researchers found miR-675 regulated cellproliferation of GC cells by targeting the tumor suppressiongene Runt Domain Transcription Factor 1 (RUNX1) andconsisted of the H19miR675RUNX1 axis pathway [45]Besides RUNX1 ISM1 is another target protein of H19 [42]All these molecules can be promising therapeutic targets ofGC

Based on the studies of H19 inGC tissue researchers wereinterested in whether H19 can apply in clinical practices asa novel noninvasion biomarker to screen gastric biomarkersZhou et al [22] selected 8 lncRNAs in which their aberrantexpression in GC tissue was previously found and validatedtheir expression in plasma They found that among 8lncRNAs HOTAIR (Homeobox protein transcript antisenseRNA) MALAT1 and H19 were highly expressed in GCplasma However another study found the opposite resultsthat HOTAIR and MALAT1 had no significant difference inexpression of patients and controls Moreover this researchidentified that MALAT1 was not so stable in the plasmawhich was contradicted by MD miniRNArsquos stability in PCaplasma even in a harsh environment [19] H19 is highlyexpressed in GC plasma and could serve as a promisingbiomarker of GC due to its high diagnostic power for detec-tion of GC (AUC 0838 specificity 729 sensitivity 829)H19 could also screen for early stage of GC (AUC 0877specificity 801 sensitivity 855) which wasmore effectivethan the conventional biomarkers such as carcinoembryonicantigen (CEA) and carbohydrate antigen 199 (CA199) [22]

5 HOTAIR in Cancer TissuesCell Lines and Body Fluids

51 Colorectal Cancer (CRC) HOTAIR had oncogenic prop-erties Its high expression in CRC tissues was closely relatedto vascular invasion histological differentiation and livermetastasis [46 47] Patients with high expression of HOTAIRwere more likely to have tumor recurrence and poor prog-nosis Furthermore Cai et al [48] did a meta-analysis whichincluded 748 patients from 8 studies to evaluate the associ-ation between HOTAIR expression levels and lymph nodemetastasis They identified that patients with high expressionof HOTAIR had a high incidence of lymph node metastasisThe mechanisms of HOTAIR regulating the initiation andprogression of CRC include relying on Polycomb RepressiveComplex (PRC) complex to silence tumor suppressor genesand being involved in EMT process HOTAIR gene is locatedon chromosome 12q1313 between the HoxC11 and HoxC12exons [49] it can reprogram chromatin organization bybindingwith PRCat 51015840 domain and lysergic acid diethylamide(LSD) at 31015840 domain in CRC [46 50] PRC complex silencestumor genes at the trimethylation of histone H3 lysine

Disease Markers 5

27 (H3K27) through a methylation process PRC complexcontains an enhancer of zeste homolog 2 (EZH2) SUZ12 andEED three subunits [51] Among the three subunits EZH2 isthe core enzyme inmethyl transfer process andEED regulatesthe specialty of EZH2 by binding to target RNA [52]Wu et al[47] identified that after knocking down HOTAIR in SW480and HT29 CRC cell lines E-cadherin as marker of epithelialcell was increased and mesenchymal cell marker vimentinwas decreasedMoreover themajor proteinaseMMP9 whichimpaired the motile ability of cells was inhibited All thesestudies indicated that HOTAIR could be an independentbiomarker for CRC diagnosis

Currently there is only one study that focused onwhetherthe expression level of HOTAIR in blood can serve asa potential marker for CRC prognostic [53] This studysimultaneously detected expression levels of HOTAIR in73 CRC tissues and 84 CRC bloods Surprisingly theirresults in CRC tissues contradicted other studies that showedthere were no significant differences between tumor tissuesand noncancerous tissues whereas in blood HOTAIR wasupregulated and expressed higher in left (descendent) colontumors compared with right (ascendant) colon tumors Fur-thermore expression of HOTAIR can predict the survivaltime of patients High expression of HOTAIR had high riskof death and was associated with poor prognosis Evaluatingprognostic power ofHOTAIR by ROC curve (AUC087)mdashitsspecificity was 67 and sensitivity was 925mdashdemonstratedHOTAIR can be a negative prognostic marker not only intumor tissues but also in blood

52 Oral Squamous Cell Cancer (OSCC) The lncRNAexpression profile in OSCC was first investigated by Gibbet al [54] In OSCC HOTAIR was overexpressed in tumortissues compared to normal tissues and its high expressionwas correlated to tumor size clinical stage lymphatic nodemetastasis and histological differentiation [55 56] By knock-ing down HOTAIR in Tca8113 OSCC cell line we foundcells were arrested in G0G1 phase and apoptosis processwas accelerated The proliferation rate of cell was reducedand the invasion and migration of cell were inhibited [5556] Moreover the enrichment of EZH2 and H3K27me3 wassignificantly decreased while the expression of E-cadherinsignificantly increased after knocking down HOTAIR [5758] Treating Tca8113 and TSCCA cells with siEZH2 andsiEZH2+siHOTAIR caused E-cadherin expression levels toincrease at both mRNA and protein levels These resultselucidated HOTAIR participating in EMT process throughinteracting with EZH2 and H3K27me3 at the E-cadherinpromoter [56] Therefore HOTAIR plays a critical role inthe development and progression of OSCC and can be apredictive marker as well as a new therapeutic target inOSCC

Tang et al [59] detected lncRNA in saliva of OSCCpatients 1mL salivary samples were collected from 9 OSCCpatients and the presence of lncRNA was examined byqPCR Ct lt 40 was considered to be positive Finallythey found MALAT1 was detected in all samples but had nosignificant difference inmetastatic and nonmetastatic tissues

while HOTAIR was detected only in 59 patients and thepatients with lymph node metastasis had higher expressionof HOTAIR in saliva All these suggest detecting lncRNA insaliva may provide clinics with a noninvasive and convenienttool to screen OSCC

6 LINC00152 in Cancer Tissues Cell Linesand Body Fluids

61 Gastric Cancer (GC) LINC00152 is located on chromo-some 2p112 and its transcript length is 828 nt There wereseveral studies that demonstrated a novel long intergenicnoncoding RNA (lincRNA) LINC00152 was overexpressedin GC tissues [60 61] Pang et al [60] detected the expressionlevels of LINC00152 in 71 pairs of GC and adjacent normaltissues They found LINC00152 had significantly higherexpression levels in GC patients and this high expressionlevel was correlated with tumor invasion Its diagnostic valuewas evaluated by ROC curve (AUC 0645 specificity 681sensitivity 625) In addition compared with the normalhuman epithelial cell line GES-1 LINC00152 expression wasalso higher in GC cell lines such as BGC-823 MGC-803 andSGC-7901 [60]

Consistent with the results in GC tissues LINC00152levels in plasma significantly increased in both advancedGC patients and early GC patients In addition comparedwith preoperative plasma samples the expression level ofLINC00152 was elevated in postoperative plasma samples[26] This result was opposite to other studies The authorspeculated that operationsmay stimulate cells to release lncR-NAs into the plasma Plasma LINC00152 diagnostic value(AUC 0675 specificity 852 sensitivity 481) was betterthan conventional markers such as CEA and CA199 [26]Therefore LINC00152 can be a novel blood-based biomarkerto apply in clinical practices to diagnose GC Besides plasmagastric juice can be used in another noninvasion method forscreening for GC [62] LINC00152 could also be detected ingastric juice and its expression level was higher in the patientswith GC than normal people [60] However the function ofLINC00152 in GC is still unclear and the sample size detectedin plasma was very small Therefore further study shouldinvestigate the function of LINC00152 and expand the samplesize

7 Conclusions and Perspectives

In this review the biological functions and diagnostic valueof lncRNAs are assessed in Table 1 The largest troublesomeproblem of the treatment of various cancer is the lackof the early diagnosis approaches Some kinds of cancerscould be completely cured if the patients are diagnosed atan early stage However conventional tumor markers suchas CEA CA199 and CA129 have low specificity or lowsensitivity which leads to clinical false negative rate andfalse positive rate increase Thus finding out more effectivemarkers is urgently needed lncRNAs were formerly regarded

6 Disease Markers

Table1Ab

errant

lncR

NAs

expressio

nin

vario

uscancers

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

MALA

T1NSC

LC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GADPH

qRT-PC

RNull

[29]

Tissue

Up

Qiagen

RNeasy

Micro

Kit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[30]

Celllines

(A549HTB

53

565758)

Up

TRIzolRe

agent

[2931]

(Invitro

gen)

QiagenR

Neasy

Micro

Kit[30]

GADPH

SYBR

-Green

qRT-PC

RNull

[29ndash

31]

Perip

heralw

holebloo

dDow

nAxyPrepBloo

dTo

talR

NAMiniprep

kit

GAPD

HqR

T-PC

RAU

C0718

[34]

Cellularfractionof

perip

heralhum

anbloo

dDow

nRibo

Pure

Bloo

dKit

(Life

Techno

logies)

GAPD

HHPR

T1TaqM

anAU

C079

specificity96

sensitivity56

[20]

MALA

T1PC

a

Tissue

Up

TRIzolRe

agent[19]

(Invitro

gen)

GAPD

H[35]

ACTB

[19]

SYBR

-Green

qRT-PC

RNull

[1935]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)

Inpu

tamou

ntStandard

curve

metho

dSY

BR-G

reen

qRT-PC

RAU

C0836

specificity848

sensitivity586

[19]

Urin

eUp

TRIzolRe

agent

(Invitro

gen)

PSA

SYBR

-Green

qRT-PC

RAU

C(0670

and

0742)

[38]

H19

GC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

R[39]

SYBR

-Green

qRT-PC

R[4244

]Null

[394244]

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[45]

Tissue

Up

RecoverA

llTo

tal

NucleicAc

idIsolation

Kit

ACTB

TaqM

anNull

[18]

Celllines

(AGSMGC-

803

SGC-

7901SMMC-

7721

HepG2Du145P

C-3

A549)

Updo

wn

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

RNull

[39]

Disease Markers 7

Table1Con

tinued

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

Celllines

(AGSMKN

45

MG-C

803SG

C7901

GES

-1)

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

[4244

]GAPD

H[45]

SYBR

-Green

qRT-PC

RNull

[4244

45]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)Re

lativ

etothelevel

ofplasmalncRN

AsTaqM

anAU

C064

0specificity58

sensitivity74

[18]

Plasma

Up

TRIzolRe

agent

(TaK

aRa)

Standard

curve

constructedwith

lncR

NAprob

esSY

BR-G

reen

qRT-PC

RAU

C0838

specificity729

sensitivity829

[22]

HOTA

IRCR

C

Tissue

Up

ISOGEN

(Nippo

nGene)Q

IAam

pDNA

Micro

Kit[46

]AllP

repDNARNA

Minikit[47]

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[4647]

Celllines

(HT2

9SW

480)

Up

AllP

repDNARNA

Minikit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[47]

Bloo

dUp

MirV

anaIsolatio

nKit

(Life

Techno

logies)

ACTB

GAPD

H

HPR

TPP

IAG

US

18SrRNA

TaqM

anAU

C0870

specificity925

sensitivity67

[53]

HOTA

IROSC

C

Tissue

Up

TRIzolRe

agent

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[555659]

Celllines

(TSC

CATca8113)

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[56]

Saliva

Up

TRIzol(In

vitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[59]

LINC0

0152

GC

Tissue

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Celllines

(AGSBG

C-823

MGC-

803SG

C-7901)

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Gastricjuice

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

RAU

C064

5specificity681

sensitivity625

[60]

Plasma

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

R

AUC0675

specificity852

sensitivity

481

[26]

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Disease Markers 3

Tumor cell Normal cell

AGO2

NPM1

Apoptotic bodyHDL

Dendritic cell Epithelial cellsT-cellB-cell

Exosomes

Microvesicles

MVBs

Blood vessel

Circulating lncRNAs

Membrane fusion Outward budding

Major carriers of circulating lncRNAs

Secrete

Figure 1 The origin of circulating lncRNAs and several manners of circulating lncRNAs encapsulation

which genes are associated with LC metastasis Ji et al [29]utilized subtractive hybridizationmethod to analyze differentgene expressions between metastatic and nonmetastatic lungtumor tissues They identified MALAT1 expressed threefoldhigher in metastatic tumor tissues In the early stage ofnon-small cell lung cancer (NSCLC) patients with highexpression level of MALAT1 had a high risk of subsequentmetastasis and poor prognostic Schmidt et al [30] studiedthe biological function of MALAT1 at a cellular level whichfound high MALAT1 expression in mouse fibroblast cellline (NIH3T3) increased its migratory and invasive capacitywhile low MALAT1 expression in A549 cell line impaired itsformation and growth To further elucidate the mechanismof MALAT1 getting involved in metastatic process Tanoet al [31] knocked down MALAT1 by short-interferingRNA (siRNA) in A549 cells simultaneously observing somemotility-associated genes such as CTHRC1 (collagen triplehelix repeat containing) CCT4 (chaperonin-containing tail-less complex polypeptide subunit 4) and ROD1 (regulatorof differentiation 1) Expression levels were downregulated atthemRNA level whereasAIM1 (melanoma 1) LAYN (layilin)and HMMR (hyaluronan-mediated motility receptor) werereduced at both pre-mRNA and mature mRNA levels ThissuggestedMALAT1modulated genes expression at transcrip-tional and posttranscriptional levels except for regulatingsplicing to enhance cell migrationMoreover MALAT1 couldbe involved in EMT process to promote tumor metastasis[32] Gutschner et al [33] utilized Zinc Finger Nucleases(ZFN) to build loss of function cells After injection ofMALAT1 knock-out cells in the nude mice the number oftumor nodules was reduced Furthermore tumor volume

and tumor weight decreased after treatment with MALAT1antisense oligonucleotides (ASO) All these indicated thatMALAT1 could be an effective therapeutic target in lungcancer in the future

MALAT1 not only has a crucial significance in predictingmetastasis risk and may be a promising therapeutic target intreating lung cancer but also can be a diagnostic biomarkerdetectable in blood to screen lung cancer Guo et al [34]analyzed the expression level of MALAT1 in 105 lung cancerpatients and 65 healthy personsrsquo whole blood by quantitativepolymerase chain reaction (qPCR) Surprisingly LC patientshad lower expression of MALAT1 than healthy subjects inwhole blood which was contrary to the high expression ofMALAT1 in lung cancer tissues But one common thing in tis-sues andwhole bloodwas thatmetastatic lung cancer patientshad stronger expression ofMALAT1 than nonmetastatic lungcancer patients Furthermore compared with lymph nodeand pleura metastasis bone and brain metastasis had highexpression of MALAT1 In the cellular fraction of peripheralhuman blood MALAT1 as a biomarker of screening NSCLCexhibited low sensitivity of 56 and high specificity of 96which demonstratedMALAT1 cannot be an independent buta complementary biomarker to diagnose NSCLC [20]

32 Prostate Cancer (PCa) The expression level of MALAT1in PCa tissues was first investigated by Ren et al [35]They used RNA-seq method to analyze the expression oflncRNAs in 14 pairs of PCa and adjacent normal tissues Theresults showed MALAT1 was overexpressed in PCa tissuesand high expression of MALAT1 had close relationships withhigh Gleason score prostate specific antigen (PSA) and

4 Disease Markers

tumor-node-metastasis (TNM) stage Then they studied thebiological function of MALAT1 in PCa at a cellular level Invitro they silenced MALAT1 in prostate cell lines 22Rv1 andLNCaP that ultimately inhibited the migratory and invasivecapacity of cancer cells and made cell cycle be arrested inG0G1 phases [36] In vivo the growth of tumor xenograftsbecame slower andmetastatic rate was reduced after injectingMALAT1 knock-out cells in the nude mice Additionally thesurvival time of tumor mice was prolonged [36] Above allMALAT1 can be an interesting therapeutic target for PCa

Unlike the low expression of MALAT1 in the wholeblood of lung cancer patients the expression of MALAT1derived miniRNA (MDminiRNA) was elevated in plasma ofPCa patients which was consistent withMALAT1 expressionin PCa tissues PSA is a prostate-specific biomarker Asa diagnostic marker PSA alone could be very sensitivebut with low specificity which finally brings about lots ofunnecessary biopsies and repeated biopsies [37] Comparedto PSA MD miniRNA was more effective plasma-basedbiomarkers to diagnose PCa from non-PCa MD miniRNAwas also more effective at distinguishing positive prostatebiopsies and negative prostate biopsies (AUC0841) than PSA(AUC 0708) [19] MD miniRNA was very helpful to predictprostate biopsy outcome Furthermore combined PSA andMD miniRNA could improve the sensitivity and specificityof diagnosis [19] Besides plasma Wang et al [38] evaluatedthe diagnostic value of MALAT1 in urine They observedthat with the level of PSA in gray zone (4ndash10 ngmL) settingurinary MALAT1 score cut-off of 95 had higher sensitivityand specificity than the fPSA (percentage of free PSA)which is the conventional reliable index for PCs diagnosis[38] Furthermore using the probability threshold of 25more cancer could be detected and unnecessary and repeatedbiopsies could be avoided 302ndash465 in PSA 4ndash10 ngmLcohorts [38]

4 H19 in Cancer Tissues Cell Linesand Body Fluids

41 Gastric Cancer (GC) The lncRNA expression profile inGC was uncovered by Song et al [39] They recruited GCtissues and noncancerous tissues to do lncRNA microarrayanalysis which found the gene H19 expressed up to 891-foldhigher in GC tissues Initially H19 was considered as tumorsuppressor gene because of its role in inhibiting tumorigenic-ity [40 41] but recent researchers have identified that H19can play a role as an oncogene Li et al [42] have observedthat the proliferative invasive and migratory abilities of cellswere repressed after the knocking down of H19 whereasafter subcutaneously injecting SGC7901 cells in nude micewhich were transfected with H19 the rate of tumor growthtumor size tumor weight and the number of metastasisnodules were increasedThe concrete regulationmechanismsof H19 as an oncogene include regulating tumor suppressorgene p53 [43] and H19miRNAtumor suppressor gene axisYang et al [44] found the activity of p53 significantlydecreased when H19 and p53-responsive reporter plasmidswere cotransfected into AGS human gastric cell lines Zhuang

et al [45] transfected MGC803 cells with siRNA-H19 andmiR-675 mimics simultaneously and the overexpression ofmiR-675 restored siRNA-H19-induced inhibition In treatedAGS cells with pcDNA-H19 and anti-miR-675 anti-miR-675 rescues pcDNA-H19-induced promotion of GC cellproliferation These results demonstrated that H19 regulatedGC cells proliferation phenotype through miR675 Throughseveral algorithms researchers found miR-675 regulated cellproliferation of GC cells by targeting the tumor suppressiongene Runt Domain Transcription Factor 1 (RUNX1) andconsisted of the H19miR675RUNX1 axis pathway [45]Besides RUNX1 ISM1 is another target protein of H19 [42]All these molecules can be promising therapeutic targets ofGC

Based on the studies of H19 inGC tissue researchers wereinterested in whether H19 can apply in clinical practices asa novel noninvasion biomarker to screen gastric biomarkersZhou et al [22] selected 8 lncRNAs in which their aberrantexpression in GC tissue was previously found and validatedtheir expression in plasma They found that among 8lncRNAs HOTAIR (Homeobox protein transcript antisenseRNA) MALAT1 and H19 were highly expressed in GCplasma However another study found the opposite resultsthat HOTAIR and MALAT1 had no significant difference inexpression of patients and controls Moreover this researchidentified that MALAT1 was not so stable in the plasmawhich was contradicted by MD miniRNArsquos stability in PCaplasma even in a harsh environment [19] H19 is highlyexpressed in GC plasma and could serve as a promisingbiomarker of GC due to its high diagnostic power for detec-tion of GC (AUC 0838 specificity 729 sensitivity 829)H19 could also screen for early stage of GC (AUC 0877specificity 801 sensitivity 855) which wasmore effectivethan the conventional biomarkers such as carcinoembryonicantigen (CEA) and carbohydrate antigen 199 (CA199) [22]

5 HOTAIR in Cancer TissuesCell Lines and Body Fluids

51 Colorectal Cancer (CRC) HOTAIR had oncogenic prop-erties Its high expression in CRC tissues was closely relatedto vascular invasion histological differentiation and livermetastasis [46 47] Patients with high expression of HOTAIRwere more likely to have tumor recurrence and poor prog-nosis Furthermore Cai et al [48] did a meta-analysis whichincluded 748 patients from 8 studies to evaluate the associ-ation between HOTAIR expression levels and lymph nodemetastasis They identified that patients with high expressionof HOTAIR had a high incidence of lymph node metastasisThe mechanisms of HOTAIR regulating the initiation andprogression of CRC include relying on Polycomb RepressiveComplex (PRC) complex to silence tumor suppressor genesand being involved in EMT process HOTAIR gene is locatedon chromosome 12q1313 between the HoxC11 and HoxC12exons [49] it can reprogram chromatin organization bybindingwith PRCat 51015840 domain and lysergic acid diethylamide(LSD) at 31015840 domain in CRC [46 50] PRC complex silencestumor genes at the trimethylation of histone H3 lysine

Disease Markers 5

27 (H3K27) through a methylation process PRC complexcontains an enhancer of zeste homolog 2 (EZH2) SUZ12 andEED three subunits [51] Among the three subunits EZH2 isthe core enzyme inmethyl transfer process andEED regulatesthe specialty of EZH2 by binding to target RNA [52]Wu et al[47] identified that after knocking down HOTAIR in SW480and HT29 CRC cell lines E-cadherin as marker of epithelialcell was increased and mesenchymal cell marker vimentinwas decreasedMoreover themajor proteinaseMMP9 whichimpaired the motile ability of cells was inhibited All thesestudies indicated that HOTAIR could be an independentbiomarker for CRC diagnosis

Currently there is only one study that focused onwhetherthe expression level of HOTAIR in blood can serve asa potential marker for CRC prognostic [53] This studysimultaneously detected expression levels of HOTAIR in73 CRC tissues and 84 CRC bloods Surprisingly theirresults in CRC tissues contradicted other studies that showedthere were no significant differences between tumor tissuesand noncancerous tissues whereas in blood HOTAIR wasupregulated and expressed higher in left (descendent) colontumors compared with right (ascendant) colon tumors Fur-thermore expression of HOTAIR can predict the survivaltime of patients High expression of HOTAIR had high riskof death and was associated with poor prognosis Evaluatingprognostic power ofHOTAIR by ROC curve (AUC087)mdashitsspecificity was 67 and sensitivity was 925mdashdemonstratedHOTAIR can be a negative prognostic marker not only intumor tissues but also in blood

52 Oral Squamous Cell Cancer (OSCC) The lncRNAexpression profile in OSCC was first investigated by Gibbet al [54] In OSCC HOTAIR was overexpressed in tumortissues compared to normal tissues and its high expressionwas correlated to tumor size clinical stage lymphatic nodemetastasis and histological differentiation [55 56] By knock-ing down HOTAIR in Tca8113 OSCC cell line we foundcells were arrested in G0G1 phase and apoptosis processwas accelerated The proliferation rate of cell was reducedand the invasion and migration of cell were inhibited [5556] Moreover the enrichment of EZH2 and H3K27me3 wassignificantly decreased while the expression of E-cadherinsignificantly increased after knocking down HOTAIR [5758] Treating Tca8113 and TSCCA cells with siEZH2 andsiEZH2+siHOTAIR caused E-cadherin expression levels toincrease at both mRNA and protein levels These resultselucidated HOTAIR participating in EMT process throughinteracting with EZH2 and H3K27me3 at the E-cadherinpromoter [56] Therefore HOTAIR plays a critical role inthe development and progression of OSCC and can be apredictive marker as well as a new therapeutic target inOSCC

Tang et al [59] detected lncRNA in saliva of OSCCpatients 1mL salivary samples were collected from 9 OSCCpatients and the presence of lncRNA was examined byqPCR Ct lt 40 was considered to be positive Finallythey found MALAT1 was detected in all samples but had nosignificant difference inmetastatic and nonmetastatic tissues

while HOTAIR was detected only in 59 patients and thepatients with lymph node metastasis had higher expressionof HOTAIR in saliva All these suggest detecting lncRNA insaliva may provide clinics with a noninvasive and convenienttool to screen OSCC

6 LINC00152 in Cancer Tissues Cell Linesand Body Fluids

61 Gastric Cancer (GC) LINC00152 is located on chromo-some 2p112 and its transcript length is 828 nt There wereseveral studies that demonstrated a novel long intergenicnoncoding RNA (lincRNA) LINC00152 was overexpressedin GC tissues [60 61] Pang et al [60] detected the expressionlevels of LINC00152 in 71 pairs of GC and adjacent normaltissues They found LINC00152 had significantly higherexpression levels in GC patients and this high expressionlevel was correlated with tumor invasion Its diagnostic valuewas evaluated by ROC curve (AUC 0645 specificity 681sensitivity 625) In addition compared with the normalhuman epithelial cell line GES-1 LINC00152 expression wasalso higher in GC cell lines such as BGC-823 MGC-803 andSGC-7901 [60]

Consistent with the results in GC tissues LINC00152levels in plasma significantly increased in both advancedGC patients and early GC patients In addition comparedwith preoperative plasma samples the expression level ofLINC00152 was elevated in postoperative plasma samples[26] This result was opposite to other studies The authorspeculated that operationsmay stimulate cells to release lncR-NAs into the plasma Plasma LINC00152 diagnostic value(AUC 0675 specificity 852 sensitivity 481) was betterthan conventional markers such as CEA and CA199 [26]Therefore LINC00152 can be a novel blood-based biomarkerto apply in clinical practices to diagnose GC Besides plasmagastric juice can be used in another noninvasion method forscreening for GC [62] LINC00152 could also be detected ingastric juice and its expression level was higher in the patientswith GC than normal people [60] However the function ofLINC00152 in GC is still unclear and the sample size detectedin plasma was very small Therefore further study shouldinvestigate the function of LINC00152 and expand the samplesize

7 Conclusions and Perspectives

In this review the biological functions and diagnostic valueof lncRNAs are assessed in Table 1 The largest troublesomeproblem of the treatment of various cancer is the lackof the early diagnosis approaches Some kinds of cancerscould be completely cured if the patients are diagnosed atan early stage However conventional tumor markers suchas CEA CA199 and CA129 have low specificity or lowsensitivity which leads to clinical false negative rate andfalse positive rate increase Thus finding out more effectivemarkers is urgently needed lncRNAs were formerly regarded

6 Disease Markers

Table1Ab

errant

lncR

NAs

expressio

nin

vario

uscancers

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

MALA

T1NSC

LC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GADPH

qRT-PC

RNull

[29]

Tissue

Up

Qiagen

RNeasy

Micro

Kit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[30]

Celllines

(A549HTB

53

565758)

Up

TRIzolRe

agent

[2931]

(Invitro

gen)

QiagenR

Neasy

Micro

Kit[30]

GADPH

SYBR

-Green

qRT-PC

RNull

[29ndash

31]

Perip

heralw

holebloo

dDow

nAxyPrepBloo

dTo

talR

NAMiniprep

kit

GAPD

HqR

T-PC

RAU

C0718

[34]

Cellularfractionof

perip

heralhum

anbloo

dDow

nRibo

Pure

Bloo

dKit

(Life

Techno

logies)

GAPD

HHPR

T1TaqM

anAU

C079

specificity96

sensitivity56

[20]

MALA

T1PC

a

Tissue

Up

TRIzolRe

agent[19]

(Invitro

gen)

GAPD

H[35]

ACTB

[19]

SYBR

-Green

qRT-PC

RNull

[1935]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)

Inpu

tamou

ntStandard

curve

metho

dSY

BR-G

reen

qRT-PC

RAU

C0836

specificity848

sensitivity586

[19]

Urin

eUp

TRIzolRe

agent

(Invitro

gen)

PSA

SYBR

-Green

qRT-PC

RAU

C(0670

and

0742)

[38]

H19

GC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

R[39]

SYBR

-Green

qRT-PC

R[4244

]Null

[394244]

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[45]

Tissue

Up

RecoverA

llTo

tal

NucleicAc

idIsolation

Kit

ACTB

TaqM

anNull

[18]

Celllines

(AGSMGC-

803

SGC-

7901SMMC-

7721

HepG2Du145P

C-3

A549)

Updo

wn

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

RNull

[39]

Disease Markers 7

Table1Con

tinued

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

Celllines

(AGSMKN

45

MG-C

803SG

C7901

GES

-1)

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

[4244

]GAPD

H[45]

SYBR

-Green

qRT-PC

RNull

[4244

45]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)Re

lativ

etothelevel

ofplasmalncRN

AsTaqM

anAU

C064

0specificity58

sensitivity74

[18]

Plasma

Up

TRIzolRe

agent

(TaK

aRa)

Standard

curve

constructedwith

lncR

NAprob

esSY

BR-G

reen

qRT-PC

RAU

C0838

specificity729

sensitivity829

[22]

HOTA

IRCR

C

Tissue

Up

ISOGEN

(Nippo

nGene)Q

IAam

pDNA

Micro

Kit[46

]AllP

repDNARNA

Minikit[47]

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[4647]

Celllines

(HT2

9SW

480)

Up

AllP

repDNARNA

Minikit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[47]

Bloo

dUp

MirV

anaIsolatio

nKit

(Life

Techno

logies)

ACTB

GAPD

H

HPR

TPP

IAG

US

18SrRNA

TaqM

anAU

C0870

specificity925

sensitivity67

[53]

HOTA

IROSC

C

Tissue

Up

TRIzolRe

agent

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[555659]

Celllines

(TSC

CATca8113)

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[56]

Saliva

Up

TRIzol(In

vitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[59]

LINC0

0152

GC

Tissue

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Celllines

(AGSBG

C-823

MGC-

803SG

C-7901)

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Gastricjuice

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

RAU

C064

5specificity681

sensitivity625

[60]

Plasma

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

R

AUC0675

specificity852

sensitivity

481

[26]

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

4 Disease Markers

tumor-node-metastasis (TNM) stage Then they studied thebiological function of MALAT1 in PCa at a cellular level Invitro they silenced MALAT1 in prostate cell lines 22Rv1 andLNCaP that ultimately inhibited the migratory and invasivecapacity of cancer cells and made cell cycle be arrested inG0G1 phases [36] In vivo the growth of tumor xenograftsbecame slower andmetastatic rate was reduced after injectingMALAT1 knock-out cells in the nude mice Additionally thesurvival time of tumor mice was prolonged [36] Above allMALAT1 can be an interesting therapeutic target for PCa

Unlike the low expression of MALAT1 in the wholeblood of lung cancer patients the expression of MALAT1derived miniRNA (MDminiRNA) was elevated in plasma ofPCa patients which was consistent withMALAT1 expressionin PCa tissues PSA is a prostate-specific biomarker Asa diagnostic marker PSA alone could be very sensitivebut with low specificity which finally brings about lots ofunnecessary biopsies and repeated biopsies [37] Comparedto PSA MD miniRNA was more effective plasma-basedbiomarkers to diagnose PCa from non-PCa MD miniRNAwas also more effective at distinguishing positive prostatebiopsies and negative prostate biopsies (AUC0841) than PSA(AUC 0708) [19] MD miniRNA was very helpful to predictprostate biopsy outcome Furthermore combined PSA andMD miniRNA could improve the sensitivity and specificityof diagnosis [19] Besides plasma Wang et al [38] evaluatedthe diagnostic value of MALAT1 in urine They observedthat with the level of PSA in gray zone (4ndash10 ngmL) settingurinary MALAT1 score cut-off of 95 had higher sensitivityand specificity than the fPSA (percentage of free PSA)which is the conventional reliable index for PCs diagnosis[38] Furthermore using the probability threshold of 25more cancer could be detected and unnecessary and repeatedbiopsies could be avoided 302ndash465 in PSA 4ndash10 ngmLcohorts [38]

4 H19 in Cancer Tissues Cell Linesand Body Fluids

41 Gastric Cancer (GC) The lncRNA expression profile inGC was uncovered by Song et al [39] They recruited GCtissues and noncancerous tissues to do lncRNA microarrayanalysis which found the gene H19 expressed up to 891-foldhigher in GC tissues Initially H19 was considered as tumorsuppressor gene because of its role in inhibiting tumorigenic-ity [40 41] but recent researchers have identified that H19can play a role as an oncogene Li et al [42] have observedthat the proliferative invasive and migratory abilities of cellswere repressed after the knocking down of H19 whereasafter subcutaneously injecting SGC7901 cells in nude micewhich were transfected with H19 the rate of tumor growthtumor size tumor weight and the number of metastasisnodules were increasedThe concrete regulationmechanismsof H19 as an oncogene include regulating tumor suppressorgene p53 [43] and H19miRNAtumor suppressor gene axisYang et al [44] found the activity of p53 significantlydecreased when H19 and p53-responsive reporter plasmidswere cotransfected into AGS human gastric cell lines Zhuang

et al [45] transfected MGC803 cells with siRNA-H19 andmiR-675 mimics simultaneously and the overexpression ofmiR-675 restored siRNA-H19-induced inhibition In treatedAGS cells with pcDNA-H19 and anti-miR-675 anti-miR-675 rescues pcDNA-H19-induced promotion of GC cellproliferation These results demonstrated that H19 regulatedGC cells proliferation phenotype through miR675 Throughseveral algorithms researchers found miR-675 regulated cellproliferation of GC cells by targeting the tumor suppressiongene Runt Domain Transcription Factor 1 (RUNX1) andconsisted of the H19miR675RUNX1 axis pathway [45]Besides RUNX1 ISM1 is another target protein of H19 [42]All these molecules can be promising therapeutic targets ofGC

Based on the studies of H19 inGC tissue researchers wereinterested in whether H19 can apply in clinical practices asa novel noninvasion biomarker to screen gastric biomarkersZhou et al [22] selected 8 lncRNAs in which their aberrantexpression in GC tissue was previously found and validatedtheir expression in plasma They found that among 8lncRNAs HOTAIR (Homeobox protein transcript antisenseRNA) MALAT1 and H19 were highly expressed in GCplasma However another study found the opposite resultsthat HOTAIR and MALAT1 had no significant difference inexpression of patients and controls Moreover this researchidentified that MALAT1 was not so stable in the plasmawhich was contradicted by MD miniRNArsquos stability in PCaplasma even in a harsh environment [19] H19 is highlyexpressed in GC plasma and could serve as a promisingbiomarker of GC due to its high diagnostic power for detec-tion of GC (AUC 0838 specificity 729 sensitivity 829)H19 could also screen for early stage of GC (AUC 0877specificity 801 sensitivity 855) which wasmore effectivethan the conventional biomarkers such as carcinoembryonicantigen (CEA) and carbohydrate antigen 199 (CA199) [22]

5 HOTAIR in Cancer TissuesCell Lines and Body Fluids

51 Colorectal Cancer (CRC) HOTAIR had oncogenic prop-erties Its high expression in CRC tissues was closely relatedto vascular invasion histological differentiation and livermetastasis [46 47] Patients with high expression of HOTAIRwere more likely to have tumor recurrence and poor prog-nosis Furthermore Cai et al [48] did a meta-analysis whichincluded 748 patients from 8 studies to evaluate the associ-ation between HOTAIR expression levels and lymph nodemetastasis They identified that patients with high expressionof HOTAIR had a high incidence of lymph node metastasisThe mechanisms of HOTAIR regulating the initiation andprogression of CRC include relying on Polycomb RepressiveComplex (PRC) complex to silence tumor suppressor genesand being involved in EMT process HOTAIR gene is locatedon chromosome 12q1313 between the HoxC11 and HoxC12exons [49] it can reprogram chromatin organization bybindingwith PRCat 51015840 domain and lysergic acid diethylamide(LSD) at 31015840 domain in CRC [46 50] PRC complex silencestumor genes at the trimethylation of histone H3 lysine

Disease Markers 5

27 (H3K27) through a methylation process PRC complexcontains an enhancer of zeste homolog 2 (EZH2) SUZ12 andEED three subunits [51] Among the three subunits EZH2 isthe core enzyme inmethyl transfer process andEED regulatesthe specialty of EZH2 by binding to target RNA [52]Wu et al[47] identified that after knocking down HOTAIR in SW480and HT29 CRC cell lines E-cadherin as marker of epithelialcell was increased and mesenchymal cell marker vimentinwas decreasedMoreover themajor proteinaseMMP9 whichimpaired the motile ability of cells was inhibited All thesestudies indicated that HOTAIR could be an independentbiomarker for CRC diagnosis

Currently there is only one study that focused onwhetherthe expression level of HOTAIR in blood can serve asa potential marker for CRC prognostic [53] This studysimultaneously detected expression levels of HOTAIR in73 CRC tissues and 84 CRC bloods Surprisingly theirresults in CRC tissues contradicted other studies that showedthere were no significant differences between tumor tissuesand noncancerous tissues whereas in blood HOTAIR wasupregulated and expressed higher in left (descendent) colontumors compared with right (ascendant) colon tumors Fur-thermore expression of HOTAIR can predict the survivaltime of patients High expression of HOTAIR had high riskof death and was associated with poor prognosis Evaluatingprognostic power ofHOTAIR by ROC curve (AUC087)mdashitsspecificity was 67 and sensitivity was 925mdashdemonstratedHOTAIR can be a negative prognostic marker not only intumor tissues but also in blood

52 Oral Squamous Cell Cancer (OSCC) The lncRNAexpression profile in OSCC was first investigated by Gibbet al [54] In OSCC HOTAIR was overexpressed in tumortissues compared to normal tissues and its high expressionwas correlated to tumor size clinical stage lymphatic nodemetastasis and histological differentiation [55 56] By knock-ing down HOTAIR in Tca8113 OSCC cell line we foundcells were arrested in G0G1 phase and apoptosis processwas accelerated The proliferation rate of cell was reducedand the invasion and migration of cell were inhibited [5556] Moreover the enrichment of EZH2 and H3K27me3 wassignificantly decreased while the expression of E-cadherinsignificantly increased after knocking down HOTAIR [5758] Treating Tca8113 and TSCCA cells with siEZH2 andsiEZH2+siHOTAIR caused E-cadherin expression levels toincrease at both mRNA and protein levels These resultselucidated HOTAIR participating in EMT process throughinteracting with EZH2 and H3K27me3 at the E-cadherinpromoter [56] Therefore HOTAIR plays a critical role inthe development and progression of OSCC and can be apredictive marker as well as a new therapeutic target inOSCC

Tang et al [59] detected lncRNA in saliva of OSCCpatients 1mL salivary samples were collected from 9 OSCCpatients and the presence of lncRNA was examined byqPCR Ct lt 40 was considered to be positive Finallythey found MALAT1 was detected in all samples but had nosignificant difference inmetastatic and nonmetastatic tissues

while HOTAIR was detected only in 59 patients and thepatients with lymph node metastasis had higher expressionof HOTAIR in saliva All these suggest detecting lncRNA insaliva may provide clinics with a noninvasive and convenienttool to screen OSCC

6 LINC00152 in Cancer Tissues Cell Linesand Body Fluids

61 Gastric Cancer (GC) LINC00152 is located on chromo-some 2p112 and its transcript length is 828 nt There wereseveral studies that demonstrated a novel long intergenicnoncoding RNA (lincRNA) LINC00152 was overexpressedin GC tissues [60 61] Pang et al [60] detected the expressionlevels of LINC00152 in 71 pairs of GC and adjacent normaltissues They found LINC00152 had significantly higherexpression levels in GC patients and this high expressionlevel was correlated with tumor invasion Its diagnostic valuewas evaluated by ROC curve (AUC 0645 specificity 681sensitivity 625) In addition compared with the normalhuman epithelial cell line GES-1 LINC00152 expression wasalso higher in GC cell lines such as BGC-823 MGC-803 andSGC-7901 [60]

Consistent with the results in GC tissues LINC00152levels in plasma significantly increased in both advancedGC patients and early GC patients In addition comparedwith preoperative plasma samples the expression level ofLINC00152 was elevated in postoperative plasma samples[26] This result was opposite to other studies The authorspeculated that operationsmay stimulate cells to release lncR-NAs into the plasma Plasma LINC00152 diagnostic value(AUC 0675 specificity 852 sensitivity 481) was betterthan conventional markers such as CEA and CA199 [26]Therefore LINC00152 can be a novel blood-based biomarkerto apply in clinical practices to diagnose GC Besides plasmagastric juice can be used in another noninvasion method forscreening for GC [62] LINC00152 could also be detected ingastric juice and its expression level was higher in the patientswith GC than normal people [60] However the function ofLINC00152 in GC is still unclear and the sample size detectedin plasma was very small Therefore further study shouldinvestigate the function of LINC00152 and expand the samplesize

7 Conclusions and Perspectives

In this review the biological functions and diagnostic valueof lncRNAs are assessed in Table 1 The largest troublesomeproblem of the treatment of various cancer is the lackof the early diagnosis approaches Some kinds of cancerscould be completely cured if the patients are diagnosed atan early stage However conventional tumor markers suchas CEA CA199 and CA129 have low specificity or lowsensitivity which leads to clinical false negative rate andfalse positive rate increase Thus finding out more effectivemarkers is urgently needed lncRNAs were formerly regarded

6 Disease Markers

Table1Ab

errant

lncR

NAs

expressio

nin

vario

uscancers

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

MALA

T1NSC

LC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GADPH

qRT-PC

RNull

[29]

Tissue

Up

Qiagen

RNeasy

Micro

Kit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[30]

Celllines

(A549HTB

53

565758)

Up

TRIzolRe

agent

[2931]

(Invitro

gen)

QiagenR

Neasy

Micro

Kit[30]

GADPH

SYBR

-Green

qRT-PC

RNull

[29ndash

31]

Perip

heralw

holebloo

dDow

nAxyPrepBloo

dTo

talR

NAMiniprep

kit

GAPD

HqR

T-PC

RAU

C0718

[34]

Cellularfractionof

perip

heralhum

anbloo

dDow

nRibo

Pure

Bloo

dKit

(Life

Techno

logies)

GAPD

HHPR

T1TaqM

anAU

C079

specificity96

sensitivity56

[20]

MALA

T1PC

a

Tissue

Up

TRIzolRe

agent[19]

(Invitro

gen)

GAPD

H[35]

ACTB

[19]

SYBR

-Green

qRT-PC

RNull

[1935]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)

Inpu

tamou

ntStandard

curve

metho

dSY

BR-G

reen

qRT-PC

RAU

C0836

specificity848

sensitivity586

[19]

Urin

eUp

TRIzolRe

agent

(Invitro

gen)

PSA

SYBR

-Green

qRT-PC

RAU

C(0670

and

0742)

[38]

H19

GC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

R[39]

SYBR

-Green

qRT-PC

R[4244

]Null

[394244]

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[45]

Tissue

Up

RecoverA

llTo

tal

NucleicAc

idIsolation

Kit

ACTB

TaqM

anNull

[18]

Celllines

(AGSMGC-

803

SGC-

7901SMMC-

7721

HepG2Du145P

C-3

A549)

Updo

wn

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

RNull

[39]

Disease Markers 7

Table1Con

tinued

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

Celllines

(AGSMKN

45

MG-C

803SG

C7901

GES

-1)

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

[4244

]GAPD

H[45]

SYBR

-Green

qRT-PC

RNull

[4244

45]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)Re

lativ

etothelevel

ofplasmalncRN

AsTaqM

anAU

C064

0specificity58

sensitivity74

[18]

Plasma

Up

TRIzolRe

agent

(TaK

aRa)

Standard

curve

constructedwith

lncR

NAprob

esSY

BR-G

reen

qRT-PC

RAU

C0838

specificity729

sensitivity829

[22]

HOTA

IRCR

C

Tissue

Up

ISOGEN

(Nippo

nGene)Q

IAam

pDNA

Micro

Kit[46

]AllP

repDNARNA

Minikit[47]

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[4647]

Celllines

(HT2

9SW

480)

Up

AllP

repDNARNA

Minikit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[47]

Bloo

dUp

MirV

anaIsolatio

nKit

(Life

Techno

logies)

ACTB

GAPD

H

HPR

TPP

IAG

US

18SrRNA

TaqM

anAU

C0870

specificity925

sensitivity67

[53]

HOTA

IROSC

C

Tissue

Up

TRIzolRe

agent

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[555659]

Celllines

(TSC

CATca8113)

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[56]

Saliva

Up

TRIzol(In

vitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[59]

LINC0

0152

GC

Tissue

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Celllines

(AGSBG

C-823

MGC-

803SG

C-7901)

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Gastricjuice

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

RAU

C064

5specificity681

sensitivity625

[60]

Plasma

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

R

AUC0675

specificity852

sensitivity

481

[26]

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Disease Markers 5

27 (H3K27) through a methylation process PRC complexcontains an enhancer of zeste homolog 2 (EZH2) SUZ12 andEED three subunits [51] Among the three subunits EZH2 isthe core enzyme inmethyl transfer process andEED regulatesthe specialty of EZH2 by binding to target RNA [52]Wu et al[47] identified that after knocking down HOTAIR in SW480and HT29 CRC cell lines E-cadherin as marker of epithelialcell was increased and mesenchymal cell marker vimentinwas decreasedMoreover themajor proteinaseMMP9 whichimpaired the motile ability of cells was inhibited All thesestudies indicated that HOTAIR could be an independentbiomarker for CRC diagnosis

Currently there is only one study that focused onwhetherthe expression level of HOTAIR in blood can serve asa potential marker for CRC prognostic [53] This studysimultaneously detected expression levels of HOTAIR in73 CRC tissues and 84 CRC bloods Surprisingly theirresults in CRC tissues contradicted other studies that showedthere were no significant differences between tumor tissuesand noncancerous tissues whereas in blood HOTAIR wasupregulated and expressed higher in left (descendent) colontumors compared with right (ascendant) colon tumors Fur-thermore expression of HOTAIR can predict the survivaltime of patients High expression of HOTAIR had high riskof death and was associated with poor prognosis Evaluatingprognostic power ofHOTAIR by ROC curve (AUC087)mdashitsspecificity was 67 and sensitivity was 925mdashdemonstratedHOTAIR can be a negative prognostic marker not only intumor tissues but also in blood

52 Oral Squamous Cell Cancer (OSCC) The lncRNAexpression profile in OSCC was first investigated by Gibbet al [54] In OSCC HOTAIR was overexpressed in tumortissues compared to normal tissues and its high expressionwas correlated to tumor size clinical stage lymphatic nodemetastasis and histological differentiation [55 56] By knock-ing down HOTAIR in Tca8113 OSCC cell line we foundcells were arrested in G0G1 phase and apoptosis processwas accelerated The proliferation rate of cell was reducedand the invasion and migration of cell were inhibited [5556] Moreover the enrichment of EZH2 and H3K27me3 wassignificantly decreased while the expression of E-cadherinsignificantly increased after knocking down HOTAIR [5758] Treating Tca8113 and TSCCA cells with siEZH2 andsiEZH2+siHOTAIR caused E-cadherin expression levels toincrease at both mRNA and protein levels These resultselucidated HOTAIR participating in EMT process throughinteracting with EZH2 and H3K27me3 at the E-cadherinpromoter [56] Therefore HOTAIR plays a critical role inthe development and progression of OSCC and can be apredictive marker as well as a new therapeutic target inOSCC

Tang et al [59] detected lncRNA in saliva of OSCCpatients 1mL salivary samples were collected from 9 OSCCpatients and the presence of lncRNA was examined byqPCR Ct lt 40 was considered to be positive Finallythey found MALAT1 was detected in all samples but had nosignificant difference inmetastatic and nonmetastatic tissues

while HOTAIR was detected only in 59 patients and thepatients with lymph node metastasis had higher expressionof HOTAIR in saliva All these suggest detecting lncRNA insaliva may provide clinics with a noninvasive and convenienttool to screen OSCC

6 LINC00152 in Cancer Tissues Cell Linesand Body Fluids

61 Gastric Cancer (GC) LINC00152 is located on chromo-some 2p112 and its transcript length is 828 nt There wereseveral studies that demonstrated a novel long intergenicnoncoding RNA (lincRNA) LINC00152 was overexpressedin GC tissues [60 61] Pang et al [60] detected the expressionlevels of LINC00152 in 71 pairs of GC and adjacent normaltissues They found LINC00152 had significantly higherexpression levels in GC patients and this high expressionlevel was correlated with tumor invasion Its diagnostic valuewas evaluated by ROC curve (AUC 0645 specificity 681sensitivity 625) In addition compared with the normalhuman epithelial cell line GES-1 LINC00152 expression wasalso higher in GC cell lines such as BGC-823 MGC-803 andSGC-7901 [60]

Consistent with the results in GC tissues LINC00152levels in plasma significantly increased in both advancedGC patients and early GC patients In addition comparedwith preoperative plasma samples the expression level ofLINC00152 was elevated in postoperative plasma samples[26] This result was opposite to other studies The authorspeculated that operationsmay stimulate cells to release lncR-NAs into the plasma Plasma LINC00152 diagnostic value(AUC 0675 specificity 852 sensitivity 481) was betterthan conventional markers such as CEA and CA199 [26]Therefore LINC00152 can be a novel blood-based biomarkerto apply in clinical practices to diagnose GC Besides plasmagastric juice can be used in another noninvasion method forscreening for GC [62] LINC00152 could also be detected ingastric juice and its expression level was higher in the patientswith GC than normal people [60] However the function ofLINC00152 in GC is still unclear and the sample size detectedin plasma was very small Therefore further study shouldinvestigate the function of LINC00152 and expand the samplesize

7 Conclusions and Perspectives

In this review the biological functions and diagnostic valueof lncRNAs are assessed in Table 1 The largest troublesomeproblem of the treatment of various cancer is the lackof the early diagnosis approaches Some kinds of cancerscould be completely cured if the patients are diagnosed atan early stage However conventional tumor markers suchas CEA CA199 and CA129 have low specificity or lowsensitivity which leads to clinical false negative rate andfalse positive rate increase Thus finding out more effectivemarkers is urgently needed lncRNAs were formerly regarded

6 Disease Markers

Table1Ab

errant

lncR

NAs

expressio

nin

vario

uscancers

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

MALA

T1NSC

LC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GADPH

qRT-PC

RNull

[29]

Tissue

Up

Qiagen

RNeasy

Micro

Kit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[30]

Celllines

(A549HTB

53

565758)

Up

TRIzolRe

agent

[2931]

(Invitro

gen)

QiagenR

Neasy

Micro

Kit[30]

GADPH

SYBR

-Green

qRT-PC

RNull

[29ndash

31]

Perip

heralw

holebloo

dDow

nAxyPrepBloo

dTo

talR

NAMiniprep

kit

GAPD

HqR

T-PC

RAU

C0718

[34]

Cellularfractionof

perip

heralhum

anbloo

dDow

nRibo

Pure

Bloo

dKit

(Life

Techno

logies)

GAPD

HHPR

T1TaqM

anAU

C079

specificity96

sensitivity56

[20]

MALA

T1PC

a

Tissue

Up

TRIzolRe

agent[19]

(Invitro

gen)

GAPD

H[35]

ACTB

[19]

SYBR

-Green

qRT-PC

RNull

[1935]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)

Inpu

tamou

ntStandard

curve

metho

dSY

BR-G

reen

qRT-PC

RAU

C0836

specificity848

sensitivity586

[19]

Urin

eUp

TRIzolRe

agent

(Invitro

gen)

PSA

SYBR

-Green

qRT-PC

RAU

C(0670

and

0742)

[38]

H19

GC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

R[39]

SYBR

-Green

qRT-PC

R[4244

]Null

[394244]

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[45]

Tissue

Up

RecoverA

llTo

tal

NucleicAc

idIsolation

Kit

ACTB

TaqM

anNull

[18]

Celllines

(AGSMGC-

803

SGC-

7901SMMC-

7721

HepG2Du145P

C-3

A549)

Updo

wn

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

RNull

[39]

Disease Markers 7

Table1Con

tinued

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

Celllines

(AGSMKN

45

MG-C

803SG

C7901

GES

-1)

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

[4244

]GAPD

H[45]

SYBR

-Green

qRT-PC

RNull

[4244

45]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)Re

lativ

etothelevel

ofplasmalncRN

AsTaqM

anAU

C064

0specificity58

sensitivity74

[18]

Plasma

Up

TRIzolRe

agent

(TaK

aRa)

Standard

curve

constructedwith

lncR

NAprob

esSY

BR-G

reen

qRT-PC

RAU

C0838

specificity729

sensitivity829

[22]

HOTA

IRCR

C

Tissue

Up

ISOGEN

(Nippo

nGene)Q

IAam

pDNA

Micro

Kit[46

]AllP

repDNARNA

Minikit[47]

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[4647]

Celllines

(HT2

9SW

480)

Up

AllP

repDNARNA

Minikit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[47]

Bloo

dUp

MirV

anaIsolatio

nKit

(Life

Techno

logies)

ACTB

GAPD

H

HPR

TPP

IAG

US

18SrRNA

TaqM

anAU

C0870

specificity925

sensitivity67

[53]

HOTA

IROSC

C

Tissue

Up

TRIzolRe

agent

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[555659]

Celllines

(TSC

CATca8113)

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[56]

Saliva

Up

TRIzol(In

vitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[59]

LINC0

0152

GC

Tissue

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Celllines

(AGSBG

C-823

MGC-

803SG

C-7901)

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Gastricjuice

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

RAU

C064

5specificity681

sensitivity625

[60]

Plasma

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

R

AUC0675

specificity852

sensitivity

481

[26]

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

6 Disease Markers

Table1Ab

errant

lncR

NAs

expressio

nin

vario

uscancers

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

MALA

T1NSC

LC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GADPH

qRT-PC

RNull

[29]

Tissue

Up

Qiagen

RNeasy

Micro

Kit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[30]

Celllines

(A549HTB

53

565758)

Up

TRIzolRe

agent

[2931]

(Invitro

gen)

QiagenR

Neasy

Micro

Kit[30]

GADPH

SYBR

-Green

qRT-PC

RNull

[29ndash

31]

Perip

heralw

holebloo

dDow

nAxyPrepBloo

dTo

talR

NAMiniprep

kit

GAPD

HqR

T-PC

RAU

C0718

[34]

Cellularfractionof

perip

heralhum

anbloo

dDow

nRibo

Pure

Bloo

dKit

(Life

Techno

logies)

GAPD

HHPR

T1TaqM

anAU

C079

specificity96

sensitivity56

[20]

MALA

T1PC

a

Tissue

Up

TRIzolRe

agent[19]

(Invitro

gen)

GAPD

H[35]

ACTB

[19]

SYBR

-Green

qRT-PC

RNull

[1935]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)

Inpu

tamou

ntStandard

curve

metho

dSY

BR-G

reen

qRT-PC

RAU

C0836

specificity848

sensitivity586

[19]

Urin

eUp

TRIzolRe

agent

(Invitro

gen)

PSA

SYBR

-Green

qRT-PC

RAU

C(0670

and

0742)

[38]

H19

GC

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

R[39]

SYBR

-Green

qRT-PC

R[4244

]Null

[394244]

Tissue

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[45]

Tissue

Up

RecoverA

llTo

tal

NucleicAc

idIsolation

Kit

ACTB

TaqM

anNull

[18]

Celllines

(AGSMGC-

803

SGC-

7901SMMC-

7721

HepG2Du145P

C-3

A549)

Updo

wn

TRIzolRe

agent

(Invitro

gen)

ACTB

GoT

aqqR

T-PC

RNull

[39]

Disease Markers 7

Table1Con

tinued

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

Celllines

(AGSMKN

45

MG-C

803SG

C7901

GES

-1)

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

[4244

]GAPD

H[45]

SYBR

-Green

qRT-PC

RNull

[4244

45]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)Re

lativ

etothelevel

ofplasmalncRN

AsTaqM

anAU

C064

0specificity58

sensitivity74

[18]

Plasma

Up

TRIzolRe

agent

(TaK

aRa)

Standard

curve

constructedwith

lncR

NAprob

esSY

BR-G

reen

qRT-PC

RAU

C0838

specificity729

sensitivity829

[22]

HOTA

IRCR

C

Tissue

Up

ISOGEN

(Nippo

nGene)Q

IAam

pDNA

Micro

Kit[46

]AllP

repDNARNA

Minikit[47]

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[4647]

Celllines

(HT2

9SW

480)

Up

AllP

repDNARNA

Minikit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[47]

Bloo

dUp

MirV

anaIsolatio

nKit

(Life

Techno

logies)

ACTB

GAPD

H

HPR

TPP

IAG

US

18SrRNA

TaqM

anAU

C0870

specificity925

sensitivity67

[53]

HOTA

IROSC

C

Tissue

Up

TRIzolRe

agent

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[555659]

Celllines

(TSC

CATca8113)

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[56]

Saliva

Up

TRIzol(In

vitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[59]

LINC0

0152

GC

Tissue

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Celllines

(AGSBG

C-823

MGC-

803SG

C-7901)

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Gastricjuice

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

RAU

C064

5specificity681

sensitivity625

[60]

Plasma

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

R

AUC0675

specificity852

sensitivity

481

[26]

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Disease Markers 7

Table1Con

tinued

lncR

NAs

Cancer

type

Sample

Updo

wn

Extractio

nmetho

dNormalization

Quantificatio

nmetho

dDiagn

ostic

perfo

rmance

Reference

Celllines

(AGSMKN

45

MG-C

803SG

C7901

GES

-1)

Up

TRIzolRe

agent

(Invitro

gen)

ACTB

[4244

]GAPD

H[45]

SYBR

-Green

qRT-PC

RNull

[4244

45]

Plasma

Up

mirV

anaP

ARISKit

(Ambion

)Re

lativ

etothelevel

ofplasmalncRN

AsTaqM

anAU

C064

0specificity58

sensitivity74

[18]

Plasma

Up

TRIzolRe

agent

(TaK

aRa)

Standard

curve

constructedwith

lncR

NAprob

esSY

BR-G

reen

qRT-PC

RAU

C0838

specificity729

sensitivity829

[22]

HOTA

IRCR

C

Tissue

Up

ISOGEN

(Nippo

nGene)Q

IAam

pDNA

Micro

Kit[46

]AllP

repDNARNA

Minikit[47]

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[4647]

Celllines

(HT2

9SW

480)

Up

AllP

repDNARNA

Minikit

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[47]

Bloo

dUp

MirV

anaIsolatio

nKit

(Life

Techno

logies)

ACTB

GAPD

H

HPR

TPP

IAG

US

18SrRNA

TaqM

anAU

C0870

specificity925

sensitivity67

[53]

HOTA

IROSC

C

Tissue

Up

TRIzolRe

agent

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[555659]

Celllines

(TSC

CATca8113)

Up

TRIzolRe

agent

(Invitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[56]

Saliva

Up

TRIzol(In

vitro

gen)

GAPD

HSY

BR-G

reen

qRT-PC

RNull

[59]

LINC0

0152

GC

Tissue

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Celllines

(AGSBG

C-823

MGC-

803SG

C-7901)

Up

TRIzol(In

vitro

gen)

GAPD

HGoT

aqqR

T-PC

RNull

[60]

Gastricjuice

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

RAU

C064

5specificity681

sensitivity625

[60]

Plasma

Up

TRIzolLS

Reagent

(Invitro

gen)

GAPD

HGoT

aqqR

T-PC

R

AUC0675

specificity852

sensitivity

481

[26]

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

8 Disease Markers

as ldquojunkrdquo or ldquonoiserdquo within genomes which have no protein-coding ability But recently with the development of high-throughput sequencing methods such as microarray andRNA-seq researchers disproved previous ideas and foundectopic lncRNAs expression was involved in tumorigenesistumor cells proliferation invasion migration apoptosisand angiogenesis [63] Furthermore we are confident thatlncRNAs in body fluids may serve as promising biomarkersfor cancers diagnosis and prognosis Utilizing circulatinglncRNAs as biomarkers has several advantages such as thefollowing aspects (1) they have higher specificity and sen-sitivity than conventional protein-based markers (2) Theycan monitor disease status dynamically such as predictingthe survival time of patients and predicting the risk of tumormetastasis and recurrence (3) Detection of lncRNAs in bodyfluids as a noninvasion and convenient method is easy to beclinically accepted It can ease the pain from the biopsy savethe cost of patients and have good repeatability in clinicalpractice (4)They can be independent diagnostic biomarkersor a gorgeous addition to classical noninvasion biomarkers ofcancers

Although we found lncRNAs were detectable and stablein body fluids the mechanisms underlying lncRNAs secre-tion and transport to the circulation are poorly understoodMoreover lncRNAs biological functions in cancers are notthoroughly reported In our review we observed that somestudies are contradicting to each other Therefore if wewant to adopt circulating lncRNA into clinical practicefurther studies should investigate the following aspects (1)building a standardization of sample preparation such asthe following which anticoagulant should be chosen howmuch volume is required for sample collecting and howhigh the temperature should be to store the samples (2)Endogenous controls of lncRNAs in body fluids and theextraction methods should be uniformed Adopting differentendogenous control means adopting different quantitativestandards and different extract methods that have differentextract efficiency may influence the purity and concentrationof lncRNAs (3) The standard of assessing the quality oflncRNA and the credibility of qPCR results should be moreaccurate and reliable (4) The research cohort size should bebigger and have reduced selection bias as much as possible

In summary lncRNAs not only can be potential biomark-ers for early diagnosis and prognosis of cancers but also canbe critical therapeutic targets

Competing Interests

The authors declare that they have no competing interests

Authorsrsquo Contributions

The authors contributed equally to writing of this paper

References

[1] C P Ponting and T G Belgard ldquoTranscribed dark mattermeaning or mythrdquo Human Molecular Genetics vol 19 no 2pp R162ndashR168 2010

[2] O Wapinski and H Y Chang ldquoLong noncoding RNAs andhuman diseaserdquo Trends in Cell Biology vol 21 no 6 pp 354ndash361 2011

[3] C A Brosnan and O Voinnet ldquoThe long and the short ofnoncoding RNAsrdquo Current Opinion in Cell Biology vol 21 no3 pp 416ndash425 2009

[4] M V Iorio and C M Croce ldquoMicroRNA dysregulation in can-cer diagnosticsmonitoring and therapeutics A comprehensivereviewrdquo EMBO Molecular Medicine vol 4 no 3 pp 143ndash1592012

[5] J A Weber D H Baxter S Zhang et al ldquoThe microRNAspectrum in 12 body fluidsrdquo Clinical Chemistry vol 56 no 11pp 1733ndash1741 2010

[6] S Molina-Pinelo R Suarez M D Pastor et al ldquoAssociationbetween the miRNA signatures in plasma and bronchoalveolarfluid in respiratory pathologiesrdquo Disease Markers vol 32 no 4pp 221ndash230 2012

[7] N Kosaka H Izumi K Sekine and T Ochiya ldquoMicroRNA asa new immune-regulatory agent in breast milkrdquo Silence vol 1no 1 article 7 2010

[8] H Qu W Xu Y Huang and S Yang ldquoCirculating miRNAspromising biomarkers of human cancerrdquo Asian Pacific Journalof Cancer Prevention vol 12 no 5 pp 1117ndash1125 2011

[9] R Duttagupta R Jiang J Gollub R C Getts and K W JonesldquoImpact of cellular miRNAs on circulating miRNA biomarkersignaturesrdquo PLoS ONE vol 6 no 6 Article ID e20769 2011

[10] H I PassDG Beer S Joseph andPMassion ldquoBiomarkers andmolecular testing for early detection diagnosis and therapeuticprediction of lung cancerrdquoThoracic Surgery Clinics vol 23 no2 pp 211ndash224 2013

[11] T R Mercer M E Dinger and J S Mattick ldquoLong non-codingRNAs insights into functionsrdquoNature Reviews Genetics vol 10no 3 pp 155ndash159 2009

[12] Y Huang N Liu J P Wang et al ldquoRegulatory long non-codingRNA and its functionsrdquo Journal of Physiology and Biochemistryvol 68 no 4 pp 611ndash618 2012

[13] H Zhang Z Chen X Wang Z Huang Z He and Y ChenldquoLong non-coding RNA a new player in cancerrdquo Journal ofHematology and Oncology vol 6 no 1 article 37 2013

[14] M-T Qiu J-W Hu R Yin and L Xu ldquoLong noncoding RNAan emerging paradigm of cancer researchrdquo Tumor Biology vol34 no 2 pp 613ndash620 2013

[15] J E Wilusz H Sunwoo and D L Spector ldquoLong noncodingRNAs functional surprises from the RNA worldrdquo Genes andDevelopment vol 23 no 13 pp 1494ndash1504 2009

[16] S Xu S Sui J Zhang et al ldquoDownregulation of long noncodingRNA MALAT1 induces epithelial-to-mesenchymal transitionvia the PI3K-AKT pathway in breast cancerrdquo InternationalJournal of Clinical and Experimental Pathology vol 8 no 5 pp4881ndash4891 2015

[17] Q Ji X Liu X Fu et al ldquoResveratrol inhibits invasion andmetastasis of colorectal cancer cells via MALAT1 mediatedWnt120573-catenin signal pathwayrdquo PLoS ONE vol 8 no 11 ArticleID e78700 2013

[18] T Arita D Ichikawa H Konishi et al ldquoCirculating longnon-coding RNAs in plasma of patients with gastric cancerrdquoAnticancer Research vol 33 no 8 pp 3185ndash3194 2013

[19] S Ren F Wang J Shen et al ldquoLong non-coding RNA metas-tasis associated in lung adenocarcinoma transcript 1 derivedminiRNA as a novel plasma-based biomarker for diagnosingprostate cancerrdquo European Journal of Cancer vol 49 no 13 pp2949ndash2959 2013

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Disease Markers 9

[20] D G Weber G Johnen S Casjens et al ldquoEvaluation oflong noncoding RNA MALAT1 as a candidate blood-basedbiomarker for the diagnosis of non-small cell lung cancerrdquoBMCResearch Notes vol 6 article 518 2013

[21] P Gresner J Gromadzinska and W Wasowicz ldquoReferencegenes for gene expression studies on non-small cell lung cancerrdquoActa Biochimica Polonica vol 56 no 2 pp 307ndash316 2009

[22] X Zhou C Yin Y Dang F Ye and G Zhang ldquoIdentification ofthe long non-coding RNA H19 in plasma as a novel biomarkerfor diagnosis of gastric cancerrdquo Scientific Reports vol 5 ArticleID 11516 2015

[23] K Trajkovic C Hsu S Chiantia et al ldquoCeramide triggersbudding of exosome vesicles into multivesicular endosomesrdquoScience vol 319 no 5867 pp 1244ndash1247 2008

[24] R M Johnstone ldquoExosomes biological significance a concisereviewrdquo Blood Cells Molecules and Diseases vol 36 no 2 pp315ndash321 2006

[25] X Huang T Yuan M Tschannen et al ldquoCharacterization ofhuman plasma-derived exosomal RNAs by deep sequencingrdquoBMC Genomics vol 14 article 319 2013

[26] Q Li Y Shao X Zhang et al ldquoPlasma long noncoding RNAprotected by exosomes as a potential stable biomarker forgastric cancerrdquo Tumor Biology vol 36 no 3 pp 2007ndash20122015

[27] J D Arroyo J R Chevillet E M Kroh et al ldquoArgonaute2complexes carry a population of circulating microRNAs inde-pendent of vesicles in human plasmardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 108 no 12 pp 5003ndash5008 2011

[28] K Wang S Zhang J Weber D Baxter and D J GalasldquoExport of microRNAs and microRNA-protective protein bymammalian cellsrdquo Nucleic Acids Research vol 38 no 20 pp7248ndash7259 2010

[29] P Ji S Diederichs W Wang et al ldquoMALAT-1 a novel noncod-ing RNA and thymosin 1205734 predict metastasis and survival inearly-stage non-small cell lung cancerrdquo Oncogene vol 22 no39 pp 8031ndash8041 2003

[30] L H Schmidt T Spieker S Koschmieder et al ldquoThe longnoncoding MALAT-1 RNA indicates a poor prognosis in non-small cell lung cancer and induces migration and tumorgrowthrdquo Journal of Thoracic Oncology vol 6 no 12 pp 1984ndash1992 2011

[31] K Tano R Mizuno T Okada et al ldquoMALAT-1 enhancescell motility of lung adenocarcinoma cells by influencing theexpression of motility-related genesrdquo FEBS Letters vol 584 no22 pp 4575ndash4580 2010

[32] L Shen L Chen Y Wang X Jiang H Xia and Z ZhuangldquoLong noncoding RNA MALAT1 promotes brain metastasisby inducing epithelial-mesenchymal transition in lung cancerrdquoJournal of Neuro-Oncology vol 121 no 1 pp 101ndash108 2015

[33] T Gutschner M Hammerle M Eiszligmann et al ldquoThe non-coding RNA MALAT1 is a critical regulator of the metastasisphenotype of lung cancer cellsrdquo Cancer Research vol 73 no 3pp 1180ndash1189 2013

[34] F Guo F Yu J Wang et al ldquoExpression of MALAT1 in theperipheral whole blood of patientswith lung cancerrdquoBiomedicalReports vol 3 no 3 pp 309ndash312 2015

[35] S Ren Z Peng J-H Mao et al ldquoRNA-seq analysis of prostatecancer in the Chinese population identifies recurrent genefusions cancer-associated long noncoding RNAs and aberrantalternative splicingsrdquo Cell Research vol 22 no 5 pp 806ndash8212012

[36] S Ren Y LiuW Xu et al ldquoLong noncoding RNAMALAT-1 is anew potential therapeutic target for castration resistant prostatecancerrdquo The Journal of Urology vol 190 no 6 pp 2278ndash22872013

[37] B Djavan A Zlotta M Remzi et al ldquoOptimal predictors ofprostate cancer on repeat prostate biopsy a prospective studyof 1051 menrdquo Journal of Urology vol 163 no 4 pp 1144ndash11492000

[38] F Wang S Ren R Chen et al ldquoDevelopment and prospectivemulticenter evaluation of the long noncodingRNAMALAT-1 asa diagnostic urinary biomarker for prostate cancerrdquoOncotargetvol 5 no 22 pp 11091ndash11102 2014

[39] H SongW Sun G Ye et al ldquoLong non-coding RNAexpressionprofile in human gastric cancer and its clinical significancesrdquoJournal of Translational Medicine vol 11 article 225 2013

[40] I J Matouk S Mezan A Mizrahi et al ldquoThe oncofetalH19 RNA connection hypoxia p53 and cancerrdquo Biochimica etBiophysica Acta vol 1803 no 4 pp 443ndash451 2010

[41] Y Hao T Crenshaw T Moulton E Newcomb and B TyckoldquoTumour-suppressor activity of H19 RNArdquoNature vol 365 no6448 pp 764ndash767 1993

[42] H Li B Yu J Li et al ldquoOverexpression of lncRNA H19enhances carcinogenesis and metastasis of gastric cancerrdquoOncotarget vol 5 no 8 pp 2318ndash2329 2014

[43] E L Kim R Wustenberg A Rubsam et al ldquoChloroquineactivates the p53 pathway and induces apoptosis in humanglioma cellsrdquo Neuro-Oncology vol 12 no 4 pp 389ndash400 2010

[44] F Yang J Bi X Xue et al ldquoUp-regulated long non-coding RNAH19 contributes to proliferation of gastric cancer cellsrdquo FEBSJournal vol 279 no 17 pp 3159ndash3165 2012

[45] M Zhuang W Gao J Xu P Wang and Y Shu ldquoThe long non-coding RNA H19-derived miR-675 modulates human gastriccancer cell proliferation by targeting tumor suppressor RUNX1rdquoBiochemical and Biophysical Research Communications vol448 no 3 pp 315ndash322 2014

[46] R Kogo T Shimamura K Mimori et al ldquoLong noncodingRNAHOTAIR regulates polycomb-dependent chromatinmod-ification and is associated with poor prognosis in colorectalcancersrdquo Cancer Research vol 71 no 20 pp 6320ndash6326 2011

[47] Z-H Wu X-L Wang H-M Tang et al ldquoLong non-codingRNA HOTAIR is a powerful predictor of metastasis andpoor prognosis and is associated with epithelial-mesenchymaltransition in colon cancerrdquo Oncology Reports vol 32 no 1 pp395ndash402 2014

[48] B Cai Z Wu K Liao and S Zhang ldquoLong noncoding RNAHOTAIR can serve as a common molecular marker for lymphnode metastasis a meta-analysisrdquo Tumor Biology vol 35 no 9pp 8445ndash8450 2014

[49] J L RinnM Kertesz J KWang et al ldquoFunctional demarcationof active and silent chromatin domains in human HOX loci bynoncoding RNAsrdquo Cell vol 129 no 7 pp 1311ndash1323 2007

[50] M-C Tsai O Manor Y Wan et al ldquoLong noncoding RNA asmodular scaffold of histone modification complexesrdquo Sciencevol 329 no 5992 pp 689ndash693 2010

[51] R A Gupta N Shah K C Wang et al ldquoLong non-codingRNA HOTAIR reprograms chromatin state to promote cancermetastasisrdquo Nature vol 464 no 7291 pp 1071ndash1076 2010

[52] H Wu H Zeng A Dong et al ldquoStructure of the catalyticdomain of EZH2 reveals conformational plasticity in cofactorand substrate binding sites and explains oncogenic mutationsrdquoPLoS ONE vol 8 no 12 Article ID e83737 2013

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

10 Disease Markers

[53] M Svoboda J Slyskova M Schneiderova et al ldquoHOTAIR longnon-coding RNA is a negative prognostic factor not only inprimary tumors but also in the blood of colorectal cancerpatientsrdquo Carcinogenesis vol 35 no 7 pp 1510ndash1515 2014

[54] E A Gibb K S S Enfield G L Stewart et al ldquoLong non-coding RNAs are expressed in oral mucosa and altered in oralpremalignant lesionsrdquo Oral Oncology vol 47 no 11 pp 1055ndash1061 2011

[55] J Wu and H Xie ldquoExpression of long noncoding RNA-HOXtranscript antisense intergenic RNA in oral squamous cellcarcinoma and effect on cell growthrdquo Tumor Biology vol 36no 11 pp 8573ndash8578 2015

[56] Y Wu L Zhang L Zhang et al ldquoLong non-coding RNAHOTAIR promotes tumor cell invasion and metastasis byrecruiting EZH2 and repressing E-cadherin in oral squamouscell carcinomardquo International Journal of Oncology vol 46 no6 pp 2586ndash2594 2015

[57] CWang X Liu Z Chen et al ldquoPolycomb group protein EZH2-mediated E-cadherin repression promotes metastasis of oraltongue squamous cell carcinomardquo Molecular Carcinogenesisvol 52 no 3 pp 229ndash236 2013

[58] L Liu Z Xu L Zhong et al ldquoEnhancer of zeste homolog2 (EZH2) promotes tumour cell migration and invasion viaepigenetic repression of E-cadherin in renal cell carcinomardquoBJU International vol 117 no 2 pp 351ndash362 2016

[59] H Tang Z Wu J Zhang and B Su ldquoSalivary lncRNA as apotential marker for Oral squamous cell carcinoma diagnosisrdquoMolecular Medicine Reports vol 7 no 3 pp 761ndash766 2013

[60] Q Pang J Ge Y Shao et al ldquoIncreased expression of longintergenic non-coding RNA LINC00152 in gastric cancer andits clinical significancerdquo Tumor Biology vol 35 no 6 pp 5441ndash5447 2014

[61] W-J Cao H-L Wu B-S He Y-S Zhang and Z-Y ZhangldquoAnalysis of long non-coding RNA expression profiles in gastriccancerrdquo World Journal of Gastroenterology vol 19 no 23 pp3658ndash3664 2013

[62] L Cui X Zhang G Ye et al ldquoGastric juice MicroRNAsas potential biomarkers for the screening of gastric cancerrdquoCancer vol 119 no 9 pp 1618ndash1626 2013

[63] J R Prensner and A M Chinnaiyan ldquoThe emergence oflncRNAs in cancer biologyrdquo Cancer Discovery vol 1 no 5 pp391ndash407 2011

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom