title: An adaptation of the human HepaRG cells to the in vitro micronucleus assay.
abstract: The in vitro micronucleus test is considered as an attractive tool for genotoxicity testing of chemicals because of its simplicity of scoring and wide applicability in different cell types. However, most of the cells currently in use are devoid of the enzyme equipment required for activation of promutagens in the genotoxic metabolites. We postulated that the human HepaRG cell line, which can express xenobiotic metabolising enzymes at levels close to those found in primary human hepatocytes and has retained the indefinite growth capacity of transformed cells, could represent a more suitable model for genotoxicity testing of chemicals requiring metabolic activation. Based on the recommendations of the Organisation for Economic Co-operation and Development test guideline TG 487 for testing of chemicals, HepaRG cell cultures containing >80% mature hepatocytes were treated in situ with various chemicals for 24 h followed by a 3-day mitogenic stimulation with epidermal growth factor without cytokinesis block. In such culture conditions, HepaRG cells underwent >1.5 cell cycle per cell during the mitogenic stimulation. While non-genotoxic compounds (mannitol and staurosporine) did not increase the rate of micronucleated mononucleated cells, all aneugens (colchicine, nocodazole and dichlorodiphenyldichloroethylene) as well as the direct acting clastogen methyl methanesulfonate and clastogens requiring metabolic activation (aflatoxin B1, benzo(a)pyrene and 2-nitrofluorene) induced a statistically significant concentration-related increase in the number of mono-micronucleated cells. The micronucleus test was also performed after 7-day repeat exposure of HepaRG cells to the chemicals. Noticeably, a time-dependent effect was obtained with the three clastogens requiring metabolic activation. In conclusion, our results obtained with HepaRG hepatocytes exposed to various genotoxic compounds requiring or not bioactivation, compared favorably with those reported in various other cell types. They support the view that metabolically competent HepaRG cells have unique potential benefits for testing genotoxic compounds using the in vitro micronucleus assay.
authors: Inserm, UMR991, Liver Metabolisms and Cancer, F-35043 Rennes, France.
authors: Rozenn
authors: R
authors: Jossé
authors: Alexandra
authors: A
authors: Rogue
authors: Elisabeth
authors: E
authors: Lorge
authors: André
authors: A
authors: Guillouzo
mesh_terms: D024422:Aneugens / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D002461:Cell Line, Transformed; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D065702:Cytochrome P-450 CYP2B6; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D006801:Humans; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced*; D015162:Micronucleus Tests / Q000379:methods; D009152:Mutagenicity Tests; D009153:Mutagens / Q000494:pharmacology; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D015203:Reproducibility of Results; D013739:Testosterone / Q000378:metabolism; D018675:Toxicity Tests
chemical_list: D024422:Aneugens; D009153:Mutagens; D013739:Testosterone; D001189:Aryl Hydrocarbon Hydroxylases; C585599:CYP2B6 protein, human; D065702:Cytochrome P-450 CYP2B6; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D010089:Oxidoreductases, N-Demethylating