e-cadherin and catenins: molecules with versatile roles in normal and neoplastic epithelial cell...

E-Cadherin and Catenins: Molecules With Versatile Roles inNormal and Neoplastic Epithelial Cell BiologyMONA A. EL-BAHRAWY AND MASSIMO PIGNATELLI*Division of Investigative Science, Imperical College of Science, Technology and Medicine, Hammersmith Campus, Du Cane Road,London, UK

KEY WORDS adhesion; invasion; tumour progression; growth factor receptors; differentiation;cancer

ABSTRACT E-cadherin and its associated cytoplasmic proteins a-, b-, and g-catenin, play acrucial role in epithelial cell–cell adhesion and in the maintenance of tissue architecture.Perturbation in the expression or function of any of these molecules results in loss of intercellularadhesion, with possible consequent cell transformation and tumour progression. The catenins areconnected to many structural and functional proteins, which in turn influence their functions.Among these molecules are type 1 growth factor receptors, which along with other molecules arebelieved to alter the function of catenins through tyrosine phosphorylation. A recent finding is theassociation between the catenins and the adenomatous polyposis coli gene product (APC). APCmutation is an early event in colorectal carcinogenesis. It may possibly do so through perturbation ofthe critical cadherin/catenin complex. Further studies of the cadherin/catenin complex and itsconnections may give insight into the early molecular interactions critical to the initiation andprogression of tumours, which should aid in the development of novel therapeutic strategies for bothprevention and treatment. Microsc. Res. Tech. 43:224–232, 1998. r 1998 Wiley-Liss, Inc.

INTRODUCTIONThe cell membrane is concerned with adhesiveness,

which is a factor that induces cells of like constitution tostick together. Groups of cells therefore strive to attainan arrangement that is thermodynamically most stable.This affinity which cells have for their own kind is animportant mechanism in the development and mainte-nance of the architecture of multicellular animals (Wal-ter and Talbot, 1996).

A number of glycoproteins associated with the cellsurface have been identified which act as adhesionmolecules, and which bind cells either to each other orto the extracellular matrix. These have been classifiedinto five major families: cadherins, the immunoglobulinsuperfamily, the integrins, the selectins and CD44(Walter and Talbot, 1996).

THE CADHERINSThe cadherins constitute a large family of glycopro-

teins which mediate cell to cell adhesion throughcalcium-dependent, homotypic interactions (Takeichi,1991). They derive their name from their properties ascalcium-dependent cell adhesion molecules. To date,more than 16 cadherin molecules have been identified,among which are the classical E-cadherin (epithelial)and N-cadherin (neural) found in muscle and neuraltissues (Kemler, 1992). E-cadherin can be regarded asthe prototype molecule of the family. Different cadherinmolecules share common structural and functionalfeatures. They consist of an extracellular amino-terminal domain, a cell membrane spanning part, and acarboxy-cytoplasmic domain. They show a high degreeof sequence identity, especially in their cytoplasmicdomain, while the extracellular domain exhibits lesshomology (Kemler, 1992; Grunwald, 1993). Nuclearmagnetic resonance spectroscopy analysis and X-ray

crystallography have provided insights into the three-dimensional structure of the cadherin molecule (Over-duin et al., 1995; Shapiro et al., 1995). Results fromthese studies suggested that two extracellular domainmonomers are arranged in parallel to form a dimer. Thecadherin dimers from interacting cell surfaces bind insuch a way that they form a linear ‘‘zipper’’ at theintercellular contact space (Shapiro et al., 1995).

Adhesion between epithelial cells is mediated mainlyby E-cadherin (Duband et al., 1987; Takeichi, 1990).This 120-KDa transmembrane glycoprotein, knownalso as L-CAM, Uvomorulin, ARC-1, and cell-CAM120/80, is constitutively expressed in all epithelia andits gene has been mapped to chromosome 16q.22.1(Takeichi, 1991, 1988; Berx et al., 1995). Cells express-ing E-cadherin adhere to each other by homophilic(cadherin–cadherin) interaction but not to cells whichexpress other members of the cadherin family (Nose etal., 1988).

CADHERIN-ASSOCIATED CYTOPLASMICUNDERCOAT PROTEINS

E-cadherin is localised mainly in the zonula adherensjunctions.1 Its extracellular part consists of three do-mains which becomes active in the presence of calciumions. Then it interacts with the E-cadherin molecule of

1Adherens junctions are intercellular structures particularly dominant inepithelia and the myocardium that function in cell–cell adhesion and appear atregions of close cell–cell apposition as two parallel intercellular plaques intowhich actin filaments insert (Geiger et al., 1990).

*Correspondence to: Massimo Pignatelli, Division of Investigative Science,Imperial College of Science, Technology and Medicine, Hammersmith Campus,Du Cane Road, London W12 ONN, UK. E-mail: [email protected]

Received 6 April 1998; accepted in revised form 18 May 1998

MICROSCOPY RESEARCH AND TECHNIQUE 43:224–232 (1998)

r 1998 WILEY-LISS, INC.

the neighbouring cell to form a tight cell–cell adhesion.Their cytoplasmic domain is associated with a group ofclosely related but distinct undercoat proteins, termedcatenins (Takeichi, 1991; Gumbiner and McCrea, 1993).The catenins were identified by their ability to co-immunoprecipitate with the cadherins and were nameda-catenin, b-catenin, and g-catenin according to theirmobility on SDS-PAGE (Nagafuchi and Takeichi, 1988;Ozawa et al., 1989; Wheelock and Knudsen, 1991;McCrea et al., 1991; McCrea and Gumbiner, 1991).Alpha catenin is a 102-KDa protein homologous to thefocal contact-associated protein vinculin (Herren-knecht et al., 1991; Nagafuchi et al., 1991); b-catenin(88 KDa) shows homology to the Drosophila segmentpolarity gene Armadillo and to plakoglobin (McCrea etal., 1991; Butz et al., 1992), while g-catenin (82 KDa) isidentical to plakoglobin, a major component of desmo-somal and zonula adherens junctions (Butz et al., 1992;Knudsen and Wheelock, 1992). E-cadherin binds to b-or g-catenin.Alpha catenin also binds either to b-cateninor g-catenin with the result that complexes of eitherE-cadherin/b-catenin/a-catenin or E-cadherin/g-catenin/a-catenin are formed (Hinck et al., 1994a). Alphacatenin links the bound b-catenin or g-catenin to theactin microfilament network of the cytoskeleton (Hi-rano et al., 1992). Alpha catenin mediates the interac-tion between the cadherin/catenin complex and theactin cytoskeleton through its associations with a-acti-nin (Knudsen et al., 1995) and actin filaments (Rimm etal., 1995). This binding is essential for the adhesivefunction of E-cadherin and for establishment of tightphysical cell–cell adhesion (Wachsstock et al., 1987;Nagafuchi and Takeichi, 1988; Ozawa et al., 1990;Tsukita et al., 1992; Nathke et al., 1994).

A number of studies have shown that the E-cadherin/catenin complex plays a key role in cell adhesion andthat structural and functional integrity of the compo-nents of this complex is necessary for this purpose. Thisindicates that, being part of a network, cadherin func-tions cannot be fully evaluated without the consider-ation of related molecules (Shiozaki et al., 1996). Caten-ins connect cadherin to other integral membraneproteins and cytoplasmic structures (Nathke et al.,1994). The proteins that make up the junctional com-plexes of cells have been implicated in a number ofcellular events, in addition to their more obvious struc-tural role (Nieset et al., 1997).

THE ROLE OF THE CADHERIN/CATENINCOMPLEX IN TISSUE MORPHOGENESIS

Several studies suggest that cadherins are importantdeterminants of tissue morphology and developmentand that the expression of cadherins is developmentallyregulated. Differential expression of several cadherinsand distinct spatiotemporal changes in their expressionoccur during embryogenesis in association with a vari-ety of morphological events that involve cell aggrega-tion (Takeichi, 1988). Studies show that E-cadherin-mediated cell adhesion is essential for the compactionof mesenchymal cells and their transition into polarisedepithelium (Larue et al., 1994; Riethmacher et al.,1995). Expression of a dominant negative cadherinmutant in embryos of the frog Xenopus laevis resultedin perturbations of cell adhesion and tissue morphogen-esis (Levine et al., 1994; Dufour et al., 1994). Similarly,

deletion of b-catenin resulted in the absence of meso-derm formation and disturbed ectoderm development(Haegel et al., 1995). b-catenin is one of a large group offunctionally diverse proteins containing Arm repeatsequences (Peifer et al., 1994). The Arm repeats consistof 42 amino acids and are thought to act as molecularadapters that help to coordinate the actions of thesemolecules. It shows a high degree of evolutionaryconservation and shares more than 80% homology withthe Armadillo protein in Drosophila and almost com-plete homology with murine b-catenin (Peifer, 1995).

In Drosophila and in Xenopus laevis the proteinshave a role in signalling and are essential for embryonicdevelopment and tissue organisation (Peifer, 1995;Gumbiner, 1995; Gumbiner and McCrea, 1993). Deple-tion of b-catenin by injection of antisense oligonucleo-tides (Heasman et al., 1994) or anti-b-catenin antibod-ies (McCrea et al., 1993) results in failure to developnormal tissue architecture and causes defective dorsaldevelopment. On the other hand, forced overexpressionof the proteins result in tissue reduplication (Peifer etal., 1992; Peifer et al., 1993; Funayama et al., 1995;McCrea et al., 1993; Karnovsky and Klymkowsky,1995).

Alpha catenin does not associated with a-actinin incells unless a-catenin is associated with b-catenin andcadherin (Knudsen et al., 1995). It is postulated thatconformational changes induced by protein–proteininteractions in vivo expose the active binding sites ofa-catenin and a-actinin. Such regulatory mechanismsmay have important roles in controlling the assembly ofthe adherens junction and its attachment to the cyto-skeleton. The amount of actin bound complexes variesdepending on cell type and differentiation state and isbelieved to be modulated during mitosis or duringchanges of the developmental state of cells (McNeill etal., 1990; Nathke et al., 1994). This may be especiallyimportant during embryogenesis and wound healingwhen old cell–cell contacts are broken and new onesformed (Nieset et al., 1997).

ROLE OF THE CADHERIN/CATENINCOMPLEX IN TUMOUR DEVELOPMENT

AND BIOLOGICAL BEHAVIOURCadherins and catenins also have important roles in

the molecular histology of tumours and any significantchange in expression or structure of one of thesecomponents leads to adherens junction disassembly,and is implicated in loss of tumour differentiation andin the development of an invasive tumour phenotype(Smith and Pignatelli, 1997). There is a statisticallysignificant correlation between reduced expression ofE-cadherin and loss of tumour differentiation (Shim-oyama and Hirohashi, 1991), supported by in vitroresults (Vleminckx et al., 1991). In vitro studies haveshown that loss of E-cadherin-mediated intercellularadhesion is associated with an invasive and poorlydifferentiated cell phenotype in several human carci-noma cell lines (Behrens et al., 1989; Pignatelli et al.,1992; Frixen et al., 1991). Conversely, transfection ofE-cadherin cDNA into de-differentiated carcinoma cells(Frixen et al., 1991; Vlemickx et al., 1991), includingpoorly differentiated carcinoma cell lines, increasesintercellular adhesion and inhibits their invasive phe-notype (Liu et al., 1993; Breen et al., 1995). Nontrans-

225E-CADHERIN/CATENIN COMPLEX AND NEOPLASIA

formed Madin-Darby Canine Kidney epithelial cells(Behrens et al., 1989), as well as a well-differentiatedcolon carcinoma cell line (Pignatelli et al., 1992), ac-quire a de-differentiated and invasive phenotype whenintercellular adhesion is inhibited by anti-E-cadherinmonoclonal antibodies.

Expression of E-cadherin has been evaluated in vivoin a variety of human malignancies, including pancre-atic (Weinel et al., 1996), oesophageal (Jankowski et al.,1994; Miyata et al., 1994; Kadowaki et al., 1994),gastric (Matsuura et al., 1992; Oka et al., 1992; Mayeret al., 1993), and colonic (van Der Wurff et al., 1992,1994; Dorudi et al., 1993; Kinsella et al., 1993; Nigam etal., 1993; van-Aken et al., 1993; Gagliardi et al., 1995)adenocarcinomas. In these studies, reduced or absentE-cadherin expression was associated with poorly differ-entiated phenotype, infiltrative growth, and lymphnode involvement and in some cancers with tumourrecurrence and mortality (Mayer et al., 1993).

Qualitative changes in E-cadherin cellular localisa-tion appear to occur also in dysplastic lesions2 of theoesophagus with Barrett’s metaplasia (Jankowski etal., 1994), stomach (Jawhari et al., 1997), and colon(Gagliardi et al., 1995). Alteration in E-cadherin expres-sion and/or failure of E-cadherin to localise to thesurface membrane have been detected in some colorec-tal adenomas (Gagliardi et al., 1995), and cervix as incervical intraepithelial neoplasia (CIN) (Vessey et al.,1995). Figure 1 shows evident expression and membra-nous localisation of E-cadherin in the cells of thenormal pancreatic glands. This is in contrast to theweak expression and partial redistribution of E-cadherin to the cytoplasm in pancreatic adenocarci-noma cells.

We recently assessed the expression and function ofE-cadherin, type 1 growth factor receptors (EGF-R,HER-2, and HER-3) and the catenins in keratinocytestransfected with HPV-16 E6 and E7 (Wilding et al.,1996). Immortalization of normal human keratinocytesby E6 and E7 leads to altered subcellular localisationfor E-cadherin and the catenins with a shift from the

cell membrane to localisation in the cytoplasm, whilenot obviously changing their levels of expression. Pro-gression to a more aggressive phenotype capable ofinvasive growth into collagen gel seemed to correlatewith downregulation of E-cadherin together with over-expression of the epidermal growth factor receptor(EGF-R). These results confirmed our previous observa-tion that loss of membranous and appearance of cyto-plasmic cellular localisation of E-cadherin directly cor-relate with the degree of dysplasia seen in stratifiedsquamous epithelium of the uterine cervix (Vessey etal., 1995). It is apparent, therefore, that whereas loss ofE-cadherin expression is a late event in cervical carcino-genesis, perturbation of E-cadherin expression andcellular localisation occur much earlier during thedysplastic stages. This suggests that perturbation ofthe E-cadherin/catenin axis has a role in the initiationas well as progression of tumours.

In vitro studies also provide evidence for the possiblerole of a-catenin and b-catenin in the neoplastic pro-cess. Lung carcinoma PC9 cells and poorly differenti-ated colon carcinoma cell lines lacking a-catenin cannotaggregate tightly and grow as single cells despite theirexpression of E-cadherin and b-catenin (Hirano et al.,1992; Breen et al., 1993). Transfection with a-catenincDNA restores intercellular adhesion and the ability ofthese cells to form epithelioid aggregates (Shimoyamaet al., 1992; Breen et al., 1993). Similarly, the HSC-39gastric cancer cells express E-cadherin, a-catenin, andg-catenins, but do not aggregate due to mutatedb-catenin. Their nonadhesiveness is reversed aftertransfection with b-catenin cDNA (Kawanishi et al.,1995).

Immunohistochemical studies have shown thata-catenin expression is also reduced in oesophageal,gastric, colonic (Kadowaki et al., 1994; Shiozaki et al.,1994; Matsui et al., 1994), and prostatic cancers (Rich-mond et al., 1997) (Fig. 2), and was associated withtumour de-differentiation, infiltrative growth, andlymph node and liver metastasis in the former two(Kadowaki et al., 1994; Matsui et al., 1994). Further-more, reduction of a-catenin expression was a betterpredictor of local spread and distant metastasis com-pared with E-cadherin expression. b-catenin expres-sion is also frequently altered in oesophageal, gastric,and colonic cancers (Jawhari et al., 1997; Takayama et

2Dysplasia is the disturbance of tissue architecture and/or cellular morphology(Harnden and McGee, 1992).

Fig. 1. E-cadherin immunostaining in pancreatic adenocarcinoma.E-cadherin expression is confined to intercellular borders in normalpancreatic glands. In the tumour, immunoreactivity is downregulatedand heterogeneous with some cells showing diffuse cytoplasmic stain-ing and decreased membranous staining. 2003.

Fig. 2. Alpha-catenin immunostaining in prostatic adenocarci-noma. There is heterogeneous immunostaining; some cells showpositive membranous staining of variable intensity, whereas othercells show negative membranous staining. 2003.

226 M.A. EL-BAHRAWY AND M. PIGNATELLI

al., 1996). In colorectal and gastric cancer, decreasedb-catenin expression is associated with increased tu-mour grade. In addition, b-catenin has recently beenshown to be a prognostic factor independent of tumourtype, grade, and stage in gastric cancer (Jawhari et al.,1997).

RELATIONSHIP BETWEEN CELL ADHESIONAND SIGNALLING FUNCTIONS OF

b-CATENINPrevious studies have shown that cell adhesion and

growth factor receptor signalling are closely linkedprocesses. The catenins bind to other molecules, includ-ing type 1 growth factor receptors (Hotsheuzky et al.,1994; Ochiai et al., 1994), and may be involved ingrowth regulatory signalling as well as cell adhesion(Tsukita et al., 1993). It was found that b-cateninassociates with EGF-R (Hotsheuzky et al., 1994). EGF-Rmolecules are colocalised with cadherins on the basolat-eral membrane of epithelial cells, and an association ofEGF-R with the cytoskeleton has been reported (denHartigh et al., 1992). EGF-R has tyrosine kinase activ-ity, which is activated through autophosphorylationupon its binding to epidermal growth factor (EGF). Thisevent induces several changes, including alteration ofcellular morphology, cell proliferation, and induction ofcell motility in certain epithelial cells through tyrosinephosphorylation of other cellular proteins (Hotsheuzkyet al., 1994; Barrandon et al., 1987; Lund-Johansen etal., 1990). EGF induces an immediate tyrosine phosphor-ylation of b- and g-catenin. The autophosphorylatedEGF-R becomes associated with the cadherin/catenincomplex, indicating a direct interaction between EGF-Rand b-catenin which appears to be mediated by theb-catenin core region (Hoschuetzky et al., 1994).

Beta catenin is also complexed to other members ofthe cadherin protein family and might also link thesecell adhesion molecules to other members of the tyro-sine kinase receptor family. If so, b-catenin may proveto be an important regulatory protein between receptor-mediated signalling and cadherin function (Hosch-uetzky et al., 1994). Interestingly, b-catenin is thevertebrate homologue of the Drosophila segment polar-ity gene Armadillo, which participates in several devel-opmental signalling pathways (McCrea et al., 1991).Therefore, it is likely that catenins might participate insignalling pathways important for cell growth anddifferentiation (Valizadeh et al., 1997).

MODULATION OF THE CATENINFUNCTIONAL STATUS BY TYROSINE

PHOSPHORYLATIONCadherin-mediated cell adhesion may be regulated

by tyrosine phosphorylation. Immediately after ulcer-ation of the intestinal mucosa, a reparative mechanismcalled epithelial restitution is induced. The earliestresponse phase is rapid migration of viable epithelialcells from the ulcer margins over the denuded area tocover the defect and restore structural and functionalintegrity of the mucosa (Buck, 1986; Waller et al., 1988;Feil et al., 1989). Spatial and temporal changes incell–cell and cell–matrix interaction occur during cellmigration (Huttenlocher et al., 1995). Several solublefactors are involved in mucosal repair. Cell–cell junc-tional proteins seem to be commonly targeted by a

number of motogenic factors, and it is quite possiblethat the stimulatory effect of these factors on epithelialrestitution and regeneration requires modulation of theE-cadherin/catenin expression and/or function in orderto initiate cell migration (Hamaguchi et al., 1993; Kinchet al., 1995; Matsuyoshi et al., 1992; Shiozaki et al.,1995). Through studying an in vitro model of epithelialinjury, it was shown that perturbation of E-cadherin/catenin-mediated cell–cell adhesion is associated withcell migration and epithelial restitution (Hanby et al.,1996). In vivo, using immunohistochemical and in situhybridisation techniques, it was shown that in Crohn’sdisease the regeneration of epithelium over ulceratedmucosa shows altered cellular localisation and de-creased levels of E-cadherin expression (Hanby et al.,1996).

In vitro, both EGF and transforming growth factoralpha (TGF-a) promote cell migration of colonic epithe-lial cells cultured on laminin and collagen (Basson etal., 1992; Liu et al., 1994). Hepatocyte growth factor/stimulating factor (HGF/SF), a potent stimulator ofgastric epithelial cell proliferation in vitro, also pro-motes cell migration and epithelial restitution (Takaha-shi et al., 1995). The trefoil peptides3 have also beenshown to stimulate cell migration and promote epithe-lial restitution in in vitro models of epithelial injury(Dignas et al., 1994; Kindon et al., 1995). EGF andHGF/SF have been shown to induce tyrosine phosphor-ylation of b-catenin and g-catenin (Hotscheuzky et al.,1994; Shibamoto et al., 1994). This was associated withcellular redistribution of E-cadherin from membrane tocytoplasm and suppression of its function in vitro(Hotscheuzky et al., 1994; Shibamoto et al., 1994;Shiozaki et al., 1995). Trefoils were shown to inducerapid and specific tyrosine phosphorylation of b-cateninand EGF-R of some colonic carcinoma cell lines, result-ing in reduced membranous E-cadherin expression,perturbation of intercellular adhesion, and promotionof cell motility (Liu et al., 1997; Efstatiuou et al., 1998).

Further evidence for the possible role of tyrosinephosphorylation as the mechanism by which cadherin/catenin function is modulated comes from the findingthat in cells transfected with the v-Src oncogene, in-creased tyrosine phosphorylation of b-catenin andE-cadherin was observed and this posttranscriptionalmodification resulted in functional changes such as de-creased adhesion, increased migration, and increasedinvasiveness, without affecting the overall expressionof either the catenins or the cadherins (Matsuyoshi etal., 1992; Behrens et al., 1993). In ras-transformedcells, tyrosine phosphorylation of b-catenin is increasedin the detergent-soluble fraction, indicating that it isnot tightly bound to the actin cytoskeleton (Kinch et al.,1995). Similarly, EGF stimulation of A431 humanepidermoid carcinoma cells promotes tyrosine phosphor-ylation of b-catenin and increases its levels in thesoluble fraction (Hoschuezky et al., 1994). These find-ings suggest that tyrosine phosphorylation of cateninsmight be a significant mechanism that modulates theirfunction, and in turn that of E-cadherin/catenin.

3The Trefoil peptides are a family of peptides which are expressed in epithelialtissues, including the gastrointestinal tract. They are small secreted molecules inwhich the disulphide bonds between cysteine residues exhibit a common trefoilstructure (Suemori et al., 1991).


RELATIONSHIP BETWEEN ADENOMATOUSPOLYPOSIS COLI (APC) GENE PRODUCT AND

THE CADHERIN/CATENIN COMPLEXAn important finding is that b-catenin and g-catenin

associate also with the APC gene product (Su et al.,1993; Rubinfeld et al., 1993). APC protein can formdistinct complexes containing combinations of catenins,which are independent from the cadherin/catenin com-plexes, and through them bind to the cytoskeleton.However, these interactions are likely to be mutuallyinterrelated, as E-cadherin and APC directly competefor binding to b-catenin (Hulsken et al., 1994).

Mutation of the APC gene is an early event in thedevelopment of human colonic, oesophageal, and gas-tric neoplasms. Germline mutations in APC result in anautosomal dominantly inherited disease called familialadenomatous polyposis (FAP), which is characterisedby the development of multiple colorectal adenomatouspolyps with invariable progression to carcinoma (Fea-ron and Vogelstein, 1990). In vitro, mutant APC proteinhas been shown to bind more avidly to b-catenin thanwild-type APC. Binding of b-catenin to APC protein hasbeen suggested to increase b-catenin turnover, therebydecreasing b-catenin levels (Munemitsu et al., 1995).However, many mutations result in a truncated proteinwith loss of b-catenin regulatory activity (Inomata etal., 1996). It is conceivable that in dysplastic lesions ofthe gut in which there is APC mutation, a shift in theequilibrium towards b-catenin/APC complex may oc-cur. This may result in decreased E-cadherin/b-cateninbinding, loss of E-cadherin mediated adhesion, in-creased proliferation, and promotion of cell migration.

In the cell, b-catenin can be localised to both thecytoplasm, where it exists as pools of free monomericprotein, and to the lateral cell membranes as part of theE-cadherin/catenin complex. Beta catenin protein hasalso been detected in the nucleus, where it has beenshown to complex with transcription factors such aspangolin (Brunner et al., 1997) in Drosophila to initiatetranscription of genes such as engrailed (Gumbiner,1995; Behrens et al., 1996). In humans, recent workshows that b-catenin binds with the Lef-Tcf family oftranscription factors (human homologues of pangolin).In association with b-catenin, Tcf and Lef alter expres-sion of genes that may govern cell proliferation andapoptosis (Behrens et al., 1996, Molenaar et al., 1996).Regulation of the level of free cytoplasmic b-catenin is,in part at least, through the opposing actions of theAPC onco-suppressor gene and the Wnt-1 proto-oncogene. APC protein, which also contains Arm re-peats, appears to serve as a negative regulator ofcytoplasmic b-catenin (Munemitsu et al., 1995), whereasexpression of Wnt-1, the human homologue of thewingless gene in Drosophila, is associated with in-creased levels of free cytoplasmic b-catenin (Papkoff etal., 1996). One outcome of stimulation of cells by theproto-oncogene Wnt-1 is the stabilisation of b- andg-catenin proteins and their accumulation in cadherin-independent pools (Bradley et al., 1993; Hinck et al.,1994b; Papkoff et al., 1996).

Evaluation of b-catenin expression in adenomas andcancers from adenomatous polyposis coli patients and

in an experimental model (MIN mice),4 demonstratedhigh expression levels and nuclear localisation of thisprotein (Inomata et al., 1996; Valizadeh et al., 1997;Yaw Ohene-Abuakwa, 1997) (Fig. 3). Recently, colorec-tal cancer cell lines mutant for APC were found tocontain a stable nuclear Tcf-4/b-catenin complex thatconstitutively transactivates transcription. When wild-type APC was reintroduced into these cell lines,b-catenin released its association with Tcf-4 and tran-scription was inhibited (Korinek et al., 1997). Thesedata suggest that overexpression of b-catenin throughlack of APC gene function results in abnormal genetranscription that promotes tumour development.Therefore, the accumulation of b-catenin in a stableform may result in its persistent interaction withpotential effect targets that potentiate cell growth.

Mutation of the b-catenin gene CTNNB1 presumablydisrupts its functions, in both intracellular signallingand cell adhesion, leading to loss of growth control andneoplastic change. If one of the major effects of APCmutation is loss of control of normal b-catenin signal-ling, then, as argued by Morin et al., (1997), in thepresence of wild-type APC, CTNNB1 mutations mayhave much the same effect.

Beta catenin lacking the amino-terminal structure isknown to be stabilised in mammalian cells (Munemitsuet al., 1996), and such mutants have been implicated incell transformation (Whitehead et al., 1995; Oyama etal., 1994; Kawanishi et al., 1995). When b-catenin isstabilised by deletion of its amino terminus, it coloca-lises with APC protein to the ends of microtubulebundles at the tips of plasma membrane protrusions(Nathke et al., 1996). Madin-Darby Canine Kidneyepithelial cells expressing amino-deleted b-catenin ex-hibit inhibition of early cell–cell contact formation(Barth et al., 1997). Certain melanoma and colon cancercell lines that are wild-type for APC contain pointmutations in the b-catenin gene that result in theirstabilisation and persistent signalling (Rubinfeld et al.,1997a; Morin et al., 1997; Ilyas et al., 1997). These

4Multiple intestinal neoplasia (MIN) mice are heterozygous for a germlinenonsense mutation at the APC locus (APCmin), the murine homologue of APC (Suet al., 1992). The murine and human coding sequences are 86% and 90% identicalat the nucleotide and amino acid levels, respectively, with conservation ofimportant motifs. MIN mice resemble FAP patients in that they display a fullypeneterant autosomal dominant inherited predisposition to develop multipletumours in the small intestine and colon.

Fig. 3. Beta-catenin immunostaining in colorectal adenoma. Notethe intense beta-catenin immunoreactivity in the nuclei. 2003.


results suggest that mutations of CTNNB1, causingfunctional alterations in adhesion and signalling, maybe an important factor in the early development ofcolorectal cancers in the same general pathway as APCmutations. It is unclear how the consequent deregula-tion of b-catenin levels contributes to the progression ofcancer, but several lines of evidence indicate a role forb-catenin in signalling pathways controlling cell growthand differentiation (Rubinfeld et al., 1997b).

Participation of b-catenin in signal transduction isdependent on a high cytoplasmic level of b-catenin thatmay be regulated, in part, by cadherin and APC protein(Hulsken et al., 1994). Binding of b-catenin to cadherinantagonises b-catenin signalling function by sequester-ing it to the cadherin complex (Fagotto et al., 1996;Heasman et al., 1994).

Perturbation of the E-cadherin/catenin complex mayplay a role in the initiation of tumourigenesis in thegastrointestinal tract. Crypt fission is the process bywhich new intestinal crypts develop. In their study,Wasan et al. (1998) investigated the effects of APCmutation on intestinal crypt fission and epithelial cellproliferation in vivo and also qualitatively assessedfission in early FAP adenomas and 3D-reconstruction.They found a site-specific increase in crypt fission indexin FAP patients as compared to normal controls, andalso in C57BL/6J-APCmin1 APC mice as compared totheir age- and sex-matched littermate wild-type con-trols. Abnormally dividing crypts where bifurcationcommenced on the lateral crypt wall, as opposed to thecrypt base, where fission normally occurs symmetri-cally, were observed more frequently in FAP as com-pared to control. This study indicates a critical role ofAPC in the regulation of intestinal crypt production.This spatiotemporal duplication of an organised groupof cells could be considered analogous to the control ofembryonic axis duplication observed when b-catenin isoverexpressed. The control of crypt fission, a develop-mental process unique to the gut, would explain whygerm-line mutations in APC have their overwhelmingeffect site-specifically with widespread multiplicity ofintestinal tumour in FAP patients and MIN mice(Wasan et al., 1998).

CONCLUSIONSAdhesion molecules such as the E-cadherin/catenin

complex are more than just cementing substances. Inaddition to control of epithelial cell adhesion, theyappear to function as master regulatory and signallingmolecules for polarity, differentiation, proliferation,apoptosis, as well as migration and invasion. Loss ofE-cadherin/catenin function appears to be an impor-tant step in the development and progression of neoplas-tic lesions.

Continued investigation of this system should allowunravelling new aspects of cancer biology, and mayultimately lead to the development of novel therapeuticstrategies. Previous and current studies suggest thatthese molecules may/can be useful in the assessment ofthe malignant potential of preinvasive lesions and thedevelopment of prognostic markers in cancers. More-over, elucidation of the mechanisms underlying thechanges in E-cadherin and catenin function may lead tothe development of novel therapeutic approaches basedon their manipulation at the transcriptional and post-

transcriptional levels. Some studies suggest the possi-bility of modulating cell adhesion using pharmacologicagents such as tyrosine kinase inhibitors (Efstatiou etal., 1998), IL4 (Al-Tubuly et al., 1997), and nonsteroidalanti-inflammatory drugs (Mahmoud et al., 1997). Also,some dietary agents such as lectins seem to modulatethe function of these molecules (Jordinson and Pigna-telli, 1998).

REFERENCESAl-Tubuly, A., Spijker, R., Pignatelli, M., Kirkland, S., and Ritter, M.

(1997) Inhibition of growth and enhancement of differentiation ofcolorectal carcinoma cell lines by MAB MR6 and IL-4. Int. J. Cancer,71:605–611.

Barrandon, Y., and Green, H. (1987) Cell migration is essential forsustained growth of keratinocyte colonies: The roles of transforminggrowth factor-alpha and epidermal growth factor. Cell, 50:1131–1137.

Barth, A.I., Pollack, A.L., Altschuler, Y., Mostov, K.E., and Nelson, W.J.(1997) NH2-terminal deletion of beta-catenin results in stablecolocalization of mutant beta-catenin with adenomatous polyposiscoli protein and altered MDCK cell adhesion. J. Cell. Biol., 136:693–706.

Basson, M.D., Modlin, I.M., and Madri, J.A. (1992) Human enterocyte(Caco-2) migration is modulated in vitro by extracellular matrixcomposition and epidermal growth factor. J. Clin. Invest., 90:15–23.

Behrens, J., Mareel, M.M., Van-Roy, F.M., and Birchmeier, W. (1989)Dissecting tumor cell invasion: Epithelial cells acquire invasiveproperties after the loss of uvomorulin-mediated cell-cell adhesion.J. Cell. Biol., 108:2435–2447.

Behrens, J., Vakaet, L., Friis, R., Winterhager, E., Roy, V.F., Mareel,M.N., and Birchmeier, W. (1993) Loss of epithelial differentiationand gain of invasiveness correlates with tyrosine phosphorylation ofthe E-cadherin/b-catenin complex in cells transformed with a tem-perature sensitive v-Src. J. Cell. Biol., 120:757–766.

Behrens, J., von-Kries, J.P., Kuhl, M., Bruhn, L., Wedlich, D., Gross-chedl, R., and Birchmeier, W. (1996) Functional interaction ofbeta-catenin with the transcription factor LEF-1. Nature, 382:638–642.

Berx, G., Staes, K., van-Hengel, J., Molemans, F., Bussemakers, M.J.,van-Bokhoven, A., and van-Roy, F. (1995) Cloning and characteriza-tion of the human invasion suppressor gene E-cadherin (CDH1).Genomics, 26:281–289.

Bradley, R.S., Cowin, P., and Brown, A.M. (1993) Expression of Wnt-1in PC12 cells results in modulation of plakoglobin and E-cadherinand increased cellular adhesion. J. Cell. Biol., 123:1857–1865.

Breen, E., Clarke, A., Steele, G. Jr., and Mercurio, A.M. (1993) Poorlydifferentiated colon carcinoma cell lines deficient in alpha-cateninexpression express high levels of surface E-cadherin but lackCa(21)-dependent cell-cell adhesion. Cell. Adhes. Commun., 1:239–250.

Breen, E., Steele, G. Jr., and Mercurio, A.M. (1995) Role of theE-cadherin/alpha-catenin complex in modulating cell-cell and cell-matrix adhesive properties of invasive colon carcinoma cells. Ann.Surg. Oncol., 2:378–385.

Brunner, E., Peter, O., Schweizer, L., and Basler, K. (1997) pangolinencodes a Lef-1 homologue that acts downstream of Armadillo totransduce the Wingless signal in Drosophila. Nature, 385:829–833.

Buck, R.C. (1986) Ultrastructural features of rectal epithelium of themouse during the early phases of migration to repair a defect.Virchows. Arch. B. Cell. Pathol. Incl. Mol. Pathol., 51:331–340.

Butz, S., Stappert, J., Weissig, H., and Kemler, R. (1992) Plakoglobinand beta-catenin: Distinct but closely related [Letter]. Science,257:1142–1144.

den Hartigh, J.C., Van Bergen en Henegouwen, P.M., Verkleij, A.J.,and Boonstra J. (1992) The EGF-receptor is an actin bindingprotein. J. Cell. Biol., 119:349–355.

Dignass, A., Lynch-Devaney, K., Kindon, H., Thim, L., and Podolsky,D.K. (1994) Trefoil peptides promote epithelial migration through atransforming growth factor beta-independent pathway. J. Clin.Invest., 94:376–383.

Dorudi, S., Sheffield, J.P., Poulsom, R., Northover, J.M., and Hart, I.R.(1993) E-cadherin expression in colorectal cancer. An immunocyto-chemical and in situ hybridization study. Am. J. Pathol., 142:981–986.

Duband, J.L., Dufour, S., Hatta, K., Takeichi, M., Edelman, G.M., andThiery, J.P. (1987) Adhesion molecules during somitogenesis in theavian embryo. J. Cell. Biol., 104:1361–1374.


Dufour, S., Saint-Jeannet, J.P., Broders, F., Wedlich, D., and Thiery,J.P. (1994) Differential perturbations in the morphogenesis ofanterior structures induced by overexpression of truncated XB- andN-cadherins in Xenopus embryos. J. Cell. Biol., 127:521–535.

Efstathiou, J., Noda, M., Rowan, A., Dixon, C., Chinery, R., Jawhari,A., Hattori, T., Wright, N., Bodmer, W., and Pignatelli, M. (1998)Intestinal trefoil factor controls the expression of the adenomatouspolyposis coli/catenin and the E-cadherin/catenin complexes inhuman colon carcinoma cells. Proc. Natl. Acad. Sci. USA. 95:3122–3127.

Fagotto, F., Funayama, N., Gluck, U., and Gumbiner, B.M. (1996)Binding to cadherins antagonises the signalling activity of b-cateninduring axis formation in Xenopus. J. Cell. Biol., 132:1105–1114.

Fearon, E.R., and Vogelstein, B. (1990) A genetic model for colorectaltumorigenesis. Cell, 61:759–767.

Feil, W., Lacy, E.R., Wong, Y.M., Burger, D., Wenzl, E., Starlinger, M.,and Schiessel, R. (1989) Rapid epithelial restitution of human andrabbit colonic mucosa. Gastroenterology, 97:685–701.

Frixen, U.H., Behrens, J., Sachs, M., Eberle, G., Voss, B., Warda, A.,Lochner, D., and Birchmeier, W. (1991) E-cadherin-mediated cell-cell adhesion prevents invasiveness of human carcinoma cells. J.Cell. Biol., 113:173–185.

Funayama, N., Fagotto, F., McCrea, P., and Gumbiner, B.M. (1995)Embryonic axis induction by the armadillo repeat domain of beta-catenin: Evidence for intracellular signaling. J. Cell. Biol., 128:959–968.

Gagliardi, G., Kandemir, O., Liu, D., Guida, M., Benvestito, S., Ruers,T., Benjamin, I., Northover, J., Stamp, G., Talbot, I., and Pignatelli,M. (1995) Changes in E-cadherin immunoreactivity in the adenoma-carcinoma sequence of the large bowel. Virchows Arch. 426:149–154.

Geiger, B., Ginsberg, D., Salomon, D., and Volberg, T. (1990) Themolecular basis for the assembly and modulation of adherens-typejunctions. Cell. Differ. Dev., 32:343–353.

Grunwald, G.B. (1993) The structural and functional analysis ofcadherin calcium-dependent cell adhesion molecules. Curr. Opin.Cell. Biol., 5:797–805.

Gumbiner, B.M. (1995) Signal transduction of beta-catenin. Curr.Opin. Cell. Biol., 7:634–640.

Gumbiner, B.M., and McCrea, P.D. (1993) Catenins as mediators of thecytoplasmic functions of cadherins. J. Cell. Sci. Suppl., 17:155–158.

Haegel, H., Larue, L., Ohsugi, M., Fedorov, L., Herrenknecht, K., andKemler, R. (1995) Lack of beta-catenin affects mouse development atgastrulation. Development, 121:3529–3537.

Hamaguchi, M., Matsuyoshi, N., Ohnishi, Y., Gotoh, B., Takeichi, M.,and Nagai, Y. (1993) p60v-src Causes tyrosine phosphorylation andinactivation of the N-cadherin-catenin cell adhesion system. EMBOJ., 12:307–314.

Hanby, A.M., Chinery, R., Poulsom, R., Playford, R.J., and Pignatelli,M. (1996) Downregulation of E-cadherin in the reparative epithe-lium of the human gastrointestinal tract. Am. J. Pathol., 148:723–729.

Harenden, D.G., and McGee, J. O’D. (1992) Neoplasia. In: OxfordTextbook of Pathology. J. O’D McGee, P.G. Isaacson, and N.A.Wright, eds. Oxford University Press, Oxford, pp. 571–576.

Heasman, J., Crawford, A., Goldstone, K., Garner-Hamrick, P., Gum-biner, B., McCrea, P., Kintner, C., Noro, C.Y., and Wylie, C. (1994)Overexpression of cadherins and underexpression of beta-catenininhibit dorsal mesoderm induction in early Xenopus embryos. Cell,79:791–803.

Herrenknecht, K., Ozawa, M., Eckerskorn, C., Lottspeich, F., Lenter,M., and Kemler, R. (1991) The uvomorulin-anchorage protein alphacatenin is a vinculin homologue. Proc. Natl. Acad. Sci. U.S.A.,88:9156–9160.

Hinck, L., Nathke, I., Papkoff, J., and Nelson, W. (1994a) Dynamics ofcadherin/catenin complex formation: Novel protein interactions andpathways of complex assembly. J. Cell. Biol., 125:1327–1340.

Hinck, L., Nelson, W.J., and Papkoff, J. (1994b) Wnt-1 modulatescell-cell adhesion in mammalian cells by stabilizing beta-cateninbinding to the cell adhesion protein cadherin. J. Cell. Biol., 124:729–741.

Hirano, S., Kimoto, N., Shimoyama, Y., Hirohshi, S., and Takeichi, M.(1992) Identification of a neural a-catenin as a key regulator ofcadherin function and multicellular organisation. Cell, 70:293–301.

Hoschuetzky, H., Aberle, H., and Kemler, R. (1994) b-catenin mediatesthe interaction of the cadherin-catenin complex with epidermalgrowth factor receptor. J. Cell. Biol., 127:1375–1380.

Hulsken, J., Birchmeier, W., and Behrens, J. (1994) E-Cadherin andAPC compete for interaction with b-catenin and the cytoskeleton. J.Cell. Biol., 127:2061–2069.

Huttenlocher, A., Sandborg, R.R., and Horwitz, A.F. (1995) Adhesion incell migration. Curr. Opin. Cell. Biol., 7:697–706.

Ilyas, M., Tomlinson, I.P., Rowan, A., Pignatelli, M., and Bodmer, W.F.(1997) Beta-catenin mutations in cell lines established from humancolorectal cancers. Proc. Natl. Acad. Sci. U.S.A., 94:10330–10334.

Inomata, M., Ochiai, A., Akimoto, S., Kitano, S., and Hirohashi, S.(1996) Alteration of b-catenin expression in colonic epithelial cells offamilial adenomatous polyposis coli patients. Cancer Res., 56:2213–2217.

Jankowski, J., Newham, P., Kandemir, O., Hirano, S., Takeichi, M.,and Pignatelli, M. (1994) Differential expression of E-cadherin innormal, metaplastic and dysplastic eosophageal mucosa: A putativebiomarker. Int. J. Oncol., 4:441–448.

Jawhari, A., Jordans, S., Poole, S., Browne, P., Pignatelli, M., andFarthing, M.J.C. (1997) Abnormal immunoreactivity of the E-cadherin-catenin complex in gastric carcinoma: Relationship withpatient survival. Gastroenterology, 112:46–54.

Jordinson, M., and Pignatelli, M. (1998) Lectins from basic science toclinical application in cancer prevention. Exp. Opin. Invest. Drugs(in press).

Kadowaki, T., Shiozaki, H., Inoue, M., Tamura, S., Oka, H., Doki, Y.,Iihara, K., Matsui, S., Iwazawa, T., Nagafuchi, A., et al. (1994)E-cadherin and alpha-catenin expression in human esophagealcancer. Cancer. Res., 54:291–296.

Karnovsky, A., and Klymkowsky, M.W. (1995) Anterior axis duplica-tion in Xenopus induced by the over-expression of the cadherin-binding protein plakoglobin. Proc. Natl. Acad. Sci. U.S.A., 92:4522–4526.

Kawanishi, J., Kato, J., Sasaki, K., Fujii, S., Watanabe, N., and Niitsu,Y. (1995) Loss of E-cadherin-dependent cell-cell adhesion due tomutation of the beta-catenin gene in a human cancer cell line,HSC-39. Mol. Cell. Biol., 15:1175–1181.

Kemler, R. (1992) Classical cadherins. Sem. Cell. Biol., 3:149–155.Kinch, M.S., Clark, G.J., Der, C.J., and Burridge, K. (1995) Tyrosine

phosphorylation regulates the adhesions of ras-transformed breastepithelia. J. Cell. Biol., 130:461–471.

Kindon, H., Pothoulakis, C., Thim, L., Lynch-Devaney, K., and Podol-sky, D.K. (1995) Trefoil peptide protection of intestinal epithelialbarrier function: Cooperative interaction with mucin glycoprotein.Gastroenterology, 109:516–523.

Kinsella, A.R., Green, B., Lepts, G.C., Hill, C.L., Bowie, G., and Taylor,B.A. (1993) The role of the cell-cell adhesion molecule E-cadherin inlarge bowel tumour cell invasion and metastasis. Br. J. Cancer,67:904–909.

Knudsen, K.A., and Wheelock, M.J. (1992) Plakoglobin, or an 83-kDhomologue distinct from beta-catenin, interacts with E-cadherinand N-cadherin. J. Cell. Biol., 118:671–679.

Knudsen, K.A., Soler, A.P., Johnson, K.R., and Wheelock, M.J. (1995)Interaction of alpha-actinin with the cadherin/catenin cell-celladhesion complex via alpha-catenin. J. Cell. Biol., 130:67–77.

Korinek, V., Barker, N., Morin, P.J., van-Wichen, D., de-Weger, R.,Kinzler, K.W., Vogelstein, B., and Clevers, H. (1997) Constitutivetranscriptional activation by a beta-catenin-Tcf complex in ACP2/2colon carcinoma. Science, 275:1784–1787.

Larue, L., Ohsugi, M., Hirchenhain, J., and Kemler R. (1994) Cadherinnull mutant embryos fail to form a trophectoderm epithelium. Proc.Natl. Acad. Sci. U.S.A., 91:8263–8267.

Levine, E., Lee, C.H., Kintner, C., and Gumbiner, B.M. (1994) Selec-tive disruption of E-cadherin function in early Xenopus embryos bya dominant negative mutant. Development, 120:901–909.

Liu, D., El-Hariry, I., Karayannakis, A., Wilding, J., Chinery, R.,Kmiot, W., McCrea, P., Gullick, W., and Pignatelli, M. (1997)Phosphorylation of b-catenin and epidermal growth factor receptorby intestinal trefoil factor. Lab. Inv., 77(6):557–563.

Liu, D., Gagliardi, G., Nasim, M.M., Alison, M.R., Oates, T., Lalani,E.N., Stamp, G.W., and Pignatelli, M. (1994) TGF-alpha can act asmorphogen and/or mitogen in a colon-cancer cell line. Int. J. Cancer,56:603–608.

Liu, D., Nigam, A., Lalani, E., Stamp, G., and Pignatelli, M. (1993)Transfection of E-cadherin into a human colon carcinoma cell lineinduces differentiation and inhibits growth in vitro. Gut, 34(4):527.

Lund-Johansen, M., Bjerkvig, R., Humphrey, P.A., Bigner, S.H.,Bigner, D.D., and Laerum, O.D. (1990) Effect of epidermal growthfactor on glioma cell growth, migration, and invasion in vitro.Cancer. Res., 50:6039–6044.

Mahmoud, N., Boolbol, S., Bilinski, R., Martucci, C., Chadburn, A.,and Bertagnolli, M. (1997) Apc gene mutation is associated with adominant-negative effect upon intestinal cell migration. Cancer Res.15:5045–5050.

Matsui, S., Shiozaki, H., Inoue, M., Tamura, S., Doki, Y., Kadowaki, T.,Iwazawa, T., Shimaya, K., Nagafuchi, A., Tsukita, S., Mori, T. (1994)Immunohistochemical evaluation of alpha catenin expression inhuman gastric cancer. Virchows Arch., 424:375–381.


Matsuura, K., Kawanishi, J., Fujii, S., Imamura, M., Hirano, S.,Takeichi, M., and Niitsu, Y. (1992) Altered expression of E-cadherinin gastric cancer tissues and carcinomatous fluid. Br. J. Cancer,66:1122–1130.

Matsuyoshi, N., Hamaguchi, M., Taniguchi, S., Nagafuchi, A., Tsukita,S., and Takeichi, M. (1992) Cadherin-mediated cell-cell adhesion isperturbed by v-src tyrosine phosphorylation in metastatic fibro-blasts. J. Cell. Biol., 118:703–714.

Mayer, B., Johnson, J., Leitl, F., Jauch, K.W., Heiss, M.M., Schildberg,F.W., Birchmeier, W., and Funke, I. (1993) E-cadherin expression inprimary and metastatic gastric cancer: Down-regulation correlateswith cellular dedifferentiation and glandular disintegration. Can-cer. Res., 53:1690–1695.

McCrea, P.D., and Gumbiner, B.M. (1991) Purification of a 92-kDacytoplasmic protein tightly associated with the cell-cell adhesionmolecule E-cadherin (uvomorulin). Characterization and extractabil-ity of the protein complex from the cell cytostructure. J. Biol. Chem.,266:4514–4520.

McCrea, P.D., Turck, C.W., and Gumbiner, B. (1991) A Homologue ofthe armadillo protein in Drosophila (Plakoglobin) associated withE-cadherin. Science, 254:1359–1361.

McCrea, P.D., Brieher, W.M., and Gumbiner, B.M. (1993) Induction ofa secondary body axis in Xenopus by antibodies to beta-catenin. J.Cell. Biol., 123:477–484.

McNeill, H., Ozawa, M., Kemler, R., and Nelson, J. (1990) Novelfunction of the cell adhesion molecule E-Cadherin as an inducer ofcell surface polarity. Cell, 62:309–316.

Miyata, M., Shiozaki, H., Iihara, K., Shimaya, K., Oka, H., andKadowaki, T. (1994) Relationship between E-cadherin expressionand lymph node metastasis in human eosophageal cancer. Int. J.Oncol., 4:61–65.

Molenaar, M., van-de-Wetering, M., Oosterwegel, M., Peterson-Maduro, J., Godsave, S., Korinek, V., Roose, J., Destree, O., andClevers, H. (1996) XTcf-3 transcription factor mediates beta-catenin-induced axis formation in Xenopus embryos. Cell, 86:391–399.

Morin, P.J., Sparks, A.B., Korinek, V., Barker, N., Clevers, H., Vogel-stein, B., and Kinzler, K.W. (1997) Activation of beta-catenin-Tcfsignaling in colon cancer by mutations in beta-catenin or APC.Science, 275:1787–1790.

Munemitsu, S., Albert, I., Souza, B., Rubinfeld, B., and Polakis, P.(1995) Regulation of intracellular b-catenin levels by adenomatouspolyposis coli (APC) tumour-suppressor protein. Proc. Natl. Acad.Sci. USA, 92:3046–3050.

Munemitsu, S., Albert, I., Rubinfeld, B., and Polakis, P. (1996)Deletion of an amino-terminal sequence beta-catenin in vivo andpromotes hyperphosporylation of the adenomatous polyposis colitumor suppressor protein. Mol. Cell. Biol., 16:4088–4094.

Nagafuchi, A., and Takeichi, M. (1988) Cell binding function ofE-cadherin is regulated by the cytoplasmic domain. EMBO J.,7:3679–3684.

Nagafuchi, A., Takeichi, M., and Tsukita, S. (1991) The 102 kdcadherin-associated protein: Similarity to vinculin and posttranscrip-tional regulation of expression. Cell., 65:849–857.

Nathke, I., Hinck, L., Swedlow, J., Papkoff, J., and Nelson, W. (1994)Defining interactions and distributions of cadherin and catenincomplexes in polarised epithelial cells. J. Cell. Biol., 125:1341–1352.

Nathke, I.S., Adams, C.L., Polakis, P., Sellin, J.H., and Nelson, W.J.(1996) The adenomatous polyposis coli tumor suppressor proteinlocalizes to plasma membrane sites involved in active cell migration.J. Cell. Biol., 134:165–179.

Nieset, J.E., Redfield, A.R., Jin, F., Knudsen, K.A., Johnson, K.R., andWheelock, M.J. (1997) Characterization of the interactions of alpha-catenin with alpha-actinin and beta-catenin/plakoglobin. J. Cell.Sci., 110:1013–1022.

Nose, A., Nagafuchi, A., and Takeichi, M. (1988) Expressed recombi-nant cadherins mediate cell sorting in model systems. Cell, 54:993–1001.

Ochiai, A., Akimoto, S., Kanai, Y., Shibata, T., Oyama, T., andHirohashi, S. (1994) C-erbB-2 gene product associates with cateninsin human cancer cells. Biochem. Biophys. Res. Commun., 205:73–78.

Oka, H., Shiozaki, H., Kobayashi, K., Tahara, H., Tamura, S., Miyata,M., Doki, Y., Iihara, K., Matsuyoshi, N., Hirano, S., et al. (1992)Immunohistochemical evaluation of E-cadherin adhesion moleculeexpression in human gastric cancer. Virchows Arch. A. Pathol. Anat.Histopathol., 421:149–156.

Overduin, M., Harvey, T.S., Bagby, S., Tong, K.I., Yau, P., Takeichi, M.,and Ikura, M. (1995) Solution structure of the epithelial cadherindomain responsible for selective cell adhesion. Science, 267:386–389.

Oyama, T., Kanai, Y., Ochiai, A., Akimoto, S., Oda, T., Yanagihara, K.,

Nagafuchi, A., Tsukita, S., Shibamoto, S., Ito, F., et al. (1994) Atruncated beta-catenin disrupts the interaction between E-cadherinand alpha-catenin: A cause of loss of intercellular adhesiveness inhuman cancer cell lines. Cancer Res., 54:6282–6287.

Ozawa, M., Baribault, H., and Kemler, R. (1989) The cytoplasmicdomain of the cell adhesion molecule uvomorulin associates withthree independent proteins structurally related in different species.EMBO J., 8:1711–1717.

Ozawa, M., Ringwald, M., and Kemler, R. (1990) Uvomorulin-catenincomplex formation is regulated by a specific domain in the cytoplas-mic region of the cell adhesion molecule. Proc. Natl. Acad. Sci.U.S.A., 87:4246–4250.

Papkoff, J., Rubinfeld, B., Schryver, B., and Polakis, P. (1996) Wnt-1regulates free pools of catenins and stabilizes APC-catenin com-plexes. Mol. Cell. Biol., 16:2128–2134.

Peifer, M. (1995) Cell adhesion and signal transduction: The Armadilloconnection. Trends Cell. Biol., 5:224–229.

Peifer, M., McCrea, P.D., Green, K.J., Wieschaus, E., and Gumbiner,B.M. (1992) The vertebrate adhesive junction proteins beta-cateninand plakoglobin and the Drosophila segment polarity gene arma-dillo form a multigene family with similar properties. J. Cell. Biol.,118:681–691.

Peifer, M., Orsulic, S., Sweeton, D., and Wieschaus, E. (1993) A role forthe Drosophila segment polarity gene armadillo in cell adhesion andcytoskeletal integrity during oogenesis. Development, 118:1191–1207.

Peifer, M., Berg, S., and Reynolds, A.B. (1994) A repeating amino acidmotif shared by proteins with diverse cellular roles [Letter]. Cell,76:789–791.

Pignatelli, M., Liu, D., Nasim, M.M., Stamp, G.W., Hirano, S., andTakeichi, M. (1992) Morphoregulatory activities of E-cadherin andbeta-1 integrins in colorectal tumour cells. Br. J. Cancer, 66:629–634.

Richmond, P., Karayannakis, A., Nagafuchi, A., Kaisary, A., andPignatelli, M. (1997) Aberrant E-cadherin and a-catenin expressionin prostate cancer: Correlation with patient survival. Cancer Res.,57:3189–3193.

Riethmacher, D., Brinkmann, V., and Birchmeier, C. (1995) A targetedmutation in the mouse E-cadherin gene results in defective preim-plantation development. Proc. Natl. Acad. Sci. U.S.A., 92:855–859.

Rimm, D.L., Koslov, E.R., Kebriaei, P., Cianci, C.D., and Morrow, J.S.(1995) Alpha 1(E)-catenin is an actin-binding and -bundling proteinmediating the attachment of F-actin to the membrane adhesioncomplex. Proc. Natl. Acad. Sci. U.S.A., 92:8813–8817.

Rubinfeld, B., Souza, B., Albert, I., Miller, O., Chamberlain, S.,Masiarz, F., Munemitsu, S., and Polakis, P. (1993) Association of theAPC gene product with beta-catenin. Science, 262:1731–1734.

Rubinfeld, B., Robbins, P., El-Gamil, M., Albert, I., Porfiri, E., andPolakis, P. (1997a) Stabilization of beta-catenin by genetic defects inmelanoma cell lines. Science, 275:1790–1792.

Rubinfeld, B., Albert, I., Porfiri, E., Munemitsu, S., and Polakis, P.(1997b) Loss of b-catenin regulation by the APC tumour suppressorprotein correlates with loss of structure due to common somaticmutations of the gene. Cancer Res., 57:4624–4630.

Shapiro, L., Fannon, A.M., Kwong, P.D., Thompson, A., Lehmann,M.S., Grubel, G., Legrand, J.F., Als-Nielsen, J., Colman, D.R., andHendrickson, W.A. (1995) Structural basis of cell-cell adhesion bycadherins. Nature, 374:327–337.

Shibamoto, S., Hayakawa, M., Takeuchi, K., Hori, T., Oku, N.,Miyazawa, K., Kitamura, N., Takeichi, M., and Ito, F. (1994)Tyrosine phosphorylation of beta-catenin and plakoglobin enhancedby hepatocyte growth factor and epidermal growth factor in humancarcinoma cells. Cell. Adhes. Commun., 1:295–305.

Shimoyama, Y., and Hirohashi, S. (1991) Expression of E- andP-cadherin in gastric carcinoma. Cancer Res., 51:2185–2192.

Shimoyama, Y., Nagafuchi, A., Fujita, S., Gotoh, M., Takeichi, M.,Tsukita, S., and Hirohashi, S. (1992) Cadherin dysfunction in ahuman cancer cell line: Possible involvement of loss of alpha-cateninexpression in reduced cell-cell adhesiveness. Cancer. Res., 52:5770–5774.

Shiozaki, H., Iihara, K., Oka, H., Kadowaki, T., Matsui, S., Gofuku, J.,Inoue, M., Nagafuchi,A., Tsukita, S., and Mori, T. (1994) Immunohis-tochemical detection of alpha-catenin expression in human cancers.Am. J. Pathol., 144:667–674.

Shiozaki, H., Kadowaki, T., Doki, Y., Inoue, M., Tamura, S., Oka, H.,Iwazawa, T., Matsui, S., Shimaya, K., Takeichi, M., et al. (1995)Effect of epidermal growth factor on cadherin-mediated adhesion ina human oesophageal cancer cell line. Br. J. Cancer, 71:250–258.

Shiozaki, H., Oka, H., Inoue, M., Tamura, S., and Monden, M. (1996)E-cadherin mediated adhesion system in cancer cells. Cancer Suppl.,77:1605–1613.


Smith, M.E., and Pignatelli, M. (1997) The molecular histology ofneoplasia: The role of the cadherin/catenin complex. Histopathology,31:107–111.

Su, L.K., Kinzler, K.W., Vogelstein, B., Preisinger, A.C., Moser, A.R.,Luongo, C., Gould, K.A., and Dove, W.F. (1992) Multiple intestinalneoplasia caused by a mutation in the murine homologue of the APCgene. Science, 256:668–670.

Su, L.K., Vogelstein, B., and Kinzler, K.W. (1993) Association of theAPC tumour suppressor protein with catenins. Science, 262:1734–1737.

Suemori, S., Lynch-Devaney, K., and Podolsky, D.K. (1991) Identifica-tion and characterization of rat intestinal trefoil factor: Tissue- andcell-specific member of the trefoil protein family. Proc. Natl. Acad.Sci. U.S.A., 88:11017–11021.

Takahashi, M., Ota, S., Shimada, T., Hamada, E., Kawabe, T.,Okudaira, T., Matsumura, M., Kaneko, N., Terano, A., Nakamura,T., et al. (1995) Hepatocyte growth factor is the most potentendogenous stimulant of rabbit gastric epithelial cell proliferationand migration in primary culture. J. Clin. Invest., 95:1994–2003.

Takayama, T., Shiozaki, H., Shibamoto, S., Oka, H., Kimura, Y.,Tamura, S., Inoue, M., Monden, T., Ito, F., and Monden, M. (1996)Beta-catenin expression in human cancers. Am. J. Pathol., 148:39–46.

Takeichi, M. (1988) The cadherins: Cell-cell adhesion molecules control-ling animal morphogenesis. Development, 102:639–655.

Takeichi, M. (1990) Cadherins: A molecular family important inselective cell-cell adhesion. Annu. Rev. Biochem., 59:237–252.

Takeichi, M. (1991) Cadherin cell adhesion receptors as a morphoge-netic regulator. Science, 251:1451–1455.

Tsukita, S., Tsukita, S., Nagafuchi, A., and Yonemura, S. (1992)Molecular linkage between cadherins and actin filaments in cell-celladherens junctions. Curr. Opin. Cell. Biol., 4:834–839.

Tsukita, S., Itoh, M., Nagafuchi, A., Yonemura, S., and Tsukita, S.(1993) Submembranous junctional plaque proteins include potentialtumor suppressor molecules. J. Cell. Biol., 123:1049–1053.

Valizadeh, A., Karayiannakis, A.J., El-Hariry, I., Kmiot, W., andPignatelli, M. (1997) Expression of E-cadherin associated molecules(a-, b- and g-catenins and p120) in colorectal polyps. Am. J. Pathol.,150:1977–1983.

Van-Aken, J., Cuvelier, C.A., De-Wever, N., Roels, J., Gao, Y., andMareel, M.M. (1993) Immunohistochemical analysis of E-cadherinexpression in human colorectal tumours. Pathol. Res. Pract., 189:975–978.

van-der-Wurff, A.A., ten-Kate, J., van-der-Linden, E.P., Dinjens, W.N.,Arends, J.W., and Bosman, F.T. (1992) L-CAM expression in normal,premalignant, and malignant colon mucosa. J. Pathol., 168:287–291.

van-der-Wurff, A.A., Arends, J.W., van-der-Linden, E.P., ten-Kate, J.,and Bosman, F.T. (1994) L-CAM expression in lymph node and livermetastases of colorectal carcinomas. J. Pathol., 172:177–181.

Vessey, C., Wilding, J., Folarin, N., Hirano, S., Takeichi, M., Soutter, P.,Stamp, G., and Pignatelli, M. (1995) Altered expression and functionof E-cadherin in cervical intraepithelial neoplasia and invasivesquamous cell carcinoma. J. Pathol., 176:151–159.

Vleminchx, K., Vakaet, L., Mareel, M., Fiers, W., and Van Roy, F. (1991)Genetic manipulation of E-cadherin expression by epithelial tumourcells reveals an invasion suppressor role. Cell, 66:107–119.

Wachsstock, D.H., Wilkins, J.A., and Lin, S. (1987) Specific interactionof vinculin with alpha-actinin. Biochem. Biophys. Res. Commun.,146:554–560.

Waller, D.A., Thomas, N.W., and Self, T.J. (1988) Epithelial restitutionin the large intestine of the rat following insult with bile salts.Virchows Arch. A. Pathol. Anat. Histopathol., 414:77–81.

Walter, J.B., and Talbot, I.C. (1996) The normal cell. In: Walter andIsrael General Pathology. Churchill Livingstone, New York, pp.23–58.

Wasan, H., Park, H., Liu, K., Mandir, N., Winnett, A., Saseine, P.,Bodmer, W., Goodlad, R., and Wright, N. (1998) APC in the regula-tion of intestinal crypt fission. J. Pathol. 185:246–255.

Weinel, R., Neumann, K., Kisker, O., and Rosendahl, A. (1996)Expression and potential role of E-cadherin in pancreatic carci-noma. Int. J. Pancreatol., 19:25–30.

Wheelock, M.J., and Knudsen, K.A. (1991) N-cadherin-associatedproteins in chicken muscle. Differentiation, 46:35–42.

Whitehead, I., Kirk, H., and Kay, R. (1995) Expression cloning ofoncogenes by retroviral transfer of cDNA libraries. Mol. Cell. Biol.,15:704–710.

Wilding, J., Vousden, K.H., Soutter, W.P., McCrea, P.D., Del-Buono, R.,and Pignatelli, M. (1996) E-cadherin transfection down-regulatesthe epidermal growth factor receptor and reverses the invasivephenotype of human papilloma virus-transfected keratinocytes.Cancer. Res., 56:5285–5292.

Yaw Ohene-Abuakwa, D.V.M. (1997) Catenin-APC interactions ingastrointestinal epithelium. MSc Thesis, University of London.


e-cadherin and catenins: molecules with versatile roles in normal and neoplastic epithelial cell...

Documents