GENOTOXICITY ASSESSMENT OF AROMATIC-AMINES AND AMIDES IN GENETICALLY-ENGINEERED V79 CELLS

A genetically engineered V79 cell line expressing rat CYP1A2 and anoth er cell line expressing rat CYP1A2 as well as endogenous acetyltransfe rase activity, as well as CYP-deficient parental V79 cell lines, were used to assess the genotoxicity of the aromatic amines and amides 2-am inoanthracene, 2-aminofluorene, 2-acetylaminofluorene, 4-acetylaminofl uorene and 2-amino-3-methylimidazo[4,5-f]quinoline, with chromosomal a berrations and sister chromatid exchanges as the end-points. None of t he test compounds showed a clear effect on the frequency of chromosoma l aberrations in any cell line used. Sister chromatid exchanges, howev er, were induced by 2-aminoanthracene, 2-aminofluorene and 2-acetylami nofluorene in the CYP1A2-proficient cells, but not in the CYP1A2-defic ient cells. The presence of acetyltransferase activity enhanced the ef fect of 2-aminoanthracene, 2-aminofluorene and 2-acetylaminofluorene. 4-Acetylaminofluorene and 2-amino-3-methylimidazo[4,5-f]quinoline did not induce sister chromatid exchanges in the investigated cell lines. The use of cell lines with defined metabolic capabilities seems to be a valuable tool to study specific metabolic pathways important in the activation of procarcinogens.