Use of the human liver cell line Hep G2 in a modified Salmonella reversion assay

The human hepatoma cell line Hep G2 was used to activate promutagenic chemicals to mutagens in a modified Salmonella typhimurium reversion assay. Hep G2 cells mediated positive mutagenic responses in tester strain TA98 with 5 and 25 micrograms/plate of 2-aminofluorene, but these responses were consistently lower than those seen using primary rat hepatocytes. In addition, 3 and 6 X 10(6) Hep G2 cells per assay produced positive mutagenic responses with 2-aminoanthracene, benzidine, acetylbenzidine and aflatoxin B1, while benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene, 3-methylcholanthrene, 4-aminobiphenyl and 4- and 11-aminobenzo[a]pyrene were nonmutagenic with Hep G2-cell activation. These results indicate that Hep G2 cells may be a useful intact cellular metabolizing system of human origin for predicting the genotoxicity of promutagenic agents, but that the use of Salmonella as a target cell may limit the classes of mutagens detected.