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Abstracts / Toxicology L

32-02oxicogenomic profiling of formaldehyde-dependent effectsn vitro

ebecca Ceder 1, Marina Merne 2, Jan-Anders Nilsson 2, Claudiataab 3, Jan-Olov Höög 3, Roland C. Grafström 2

Karolinska Institutet, Sweden, 2 IMM, Karolinska Institutet, Sweden,MBB, Karolinska Institutet, Sweden

Toxicogenomics in vitro might serve to generate novel toxic-ty biomarkers and support the replacement of animals in toxicityesting. Toxicity of formaldehyde (FA), a human carcinogen, wastudied in a cell culture model for cancer development, includingormal (NOK), immortalized (SVpgC2a), and malignant (SqCC/Y1)ells. Repeated 1 h FA exposure of SVpgC2a caused cell transfor-ation as indicated from the evolution of a new cell line followingcrises period. The new line, termed SVpgC3a, exhibited alteredorphology, soft agar growth, but was non-tumorigenic in athymic

ude mice. Cytotoxicity and genotoxicity assessments indicatedimilar initial damage levels in all lines, whereas the longer-termonsequences differed (toxicity assessments indicated a sensi-ivity order of NOK > SVpgC2a > SVpgC3a≈SqCC/Y1). FA inducedell death primarily by terminal differentiation in NOK whereasVpgC2a, SVpgC3a and SqCC/Y1 died by other means e.g., apo-tosis. Over a dose range, the highest level of genetic damage inVpgC2a was observed at the concentration that induced transfor-ation. Proteomics and transcriptomics profiling showed that cell

ransformation coupled with multiple changes in single genes, genentologies and molecular networks. Likewise, transcript profilingf the respective cell lines for up to 48 h following FA exposurendicated multiple genomic changes, some of which overlappedo results from cancer-inducing protocols in vivo. In conclusion,he sensitivity to FA toxicity might differ between stages in can-er development. Specific gene expression changes coupled to theespective phenotypes. The SVpgC3a cell line extended the currentancer model of normal, immortal and malignant cells.

oi:10.1016/j.toxlet.2012.03.700

32-03robabilistic toxicogenomics studies in vitro

uuso Parkkinen 1, Rebecca Ceder 2, Egon Willighagen 2, Kristerennerberg 3, Samuel Kaski 4, Roland Grafström 5

Helsinki Institute for Information Tech., Finland, 2 IMM, Karolinskanstitutet, Sweden, 3 Institute for Molecular Medicine, Finland, 4 HIIT,alto University & Univ. Helsinki, Finland, 5 IMM, Karolinska

nstitutet & VTT Turku, Sweden

Background: Collections of molecular profiling and cell survivalata from drug-treated cell lines enables analyses of toxicity effectselative to gene expression changes.

Results: A probabilistic component model was applied to bioin-ormatically assess publically available microarray data from threerug-treated cell lines. Our preliminary work decomposed molec-lar changes relative to specific biological responses. As could bexpected, different drugs caused overall at toxic levels a broadange of genomic alterations, some of which differed with dose andevel of cell killing, including with differences noted also among cell

ines.

Conclusion: Although additional data sets remain to be analyzed,e foresee already that component analyses can serve to identify

211S (2012) S43–S216 S195

novel views and biomarkers for the multitude of different geneexpression changes that can drive toxicity effects.

doi:10.1016/j.toxlet.2012.03.701

P32-04Lymphocyte DNA damage in Turkish asphalt workers detectedby the comet assay

Aysegül Bacaksiz 1, Zeliha Kayaalti 1, Esma Soylemez 1, EnginTutkun 2, Tülin Soylemezoglu 1

1 Ankara University, Turkey, 2 Ankara Occupational DiseasesHospital, Turkey

Asphalt is highly complex and contains several organic com-pounds, including polycyclic aromatic hydrocarbons (PAHs) andheterocyclic compounds. According to International Agency forResearch on Cancer (IARC), PAHs in the asphalt fumes are eitherknown or suspected to be human carcinogens. Comet assay hasbeen widely used for genotoxic studies and rapid technique thatshows evidence of DNA damage in exposed population.

In this study, comet assay was used to detect the DNA damagein blood lymphocyte of 30 workers exposed to asphalt fumes and30 non-exposed individuals for control group. Hippuric acid levelswere also determined in asphalt workers as a biomarker of occu-pational exposure to PAHs. DNA damage was evaluated in terms offour image-analysis parameters, tail intensity (TI), tail DNA (DNAt),tail moment (TM), and olive tail moment (OTM).

According to our results, mean of TI, DNAt, TM and OTM inexposed group had higher than in control group and statisticallysignificant association was found between the asphalt workers andcontrol group (p < 0.01). Smoker-exposed group had significantlyhigher DNA damage than smoker-control groups (p < 0.01). Meanof TI, DNAt, TM and OTM in non-smoker exposed group had higherthan in non-smoker control group but only TI and TM were sta-tistically significant (p < 0.01). The study showed that the cometassay is a suitable biomarker in the determination of DNA damagein asphalt workers and a significant increased DNA damage wasobserved in the exposed group according to the controls.

doi:10.1016/j.toxlet.2012.03.702

P32-05The effect of blood cadmium levels in smokers to lymphocyteDNA damage

Tülin Soylemezoglu, Esma Söylemez, Zeliha Kayaalti, VugarAliyev

Ankara University, Turkey

Cigarette smoke contains high concentrations of toxic andcarcinogenic compounds that readily react to form other reac-tive substances such as polycyclic aromatic hydrocarbons,N-nitrosamines and heavy metals. Cadmium is one of the heavymetals in the cigarette smoke and effects on genome stabilityappear to be indirect, mainly via an increase in oxidative stress,causing DNA damage like single strand breaks in DNA, chromo-somal aberrations, sister chromatid exchanges and DNA–proteinbinding failures. The aim of this study was to determine Cd levels

in blood of smokers and non-smokers and investigate the relation-ship between the Cd levels and DNA damage in lymphocytes usingthe comet assay (single cell gel electrophoresis, SSGE).