Aneuploidy induction by benzo[a]pyrene and polyploidy induction by 7,12-dimethylbenz[a]anthracene in Chinese hamster cell lines V79-MZ and V79

We found that different ploidy effects were induced in fourChinese hamster-derived cell lines (V79-MZ, V79, CHL and CHO-K1)treated through two cell cycles with polycyclic aromatic hydrocarbonsin the absence of a metabolic activation system. 5-Bromodeoxyuridinewas used to investigate cell cycle delay and sister chromatidexchanges (SCE) induced by the chemicals. Benzoa]pyrene (BP)induced aneuploidy at 2.5–10 µg/ml in V79-MZ cells.7,12-Dimethylbenza]anthracene (DMBA) induced polyploidy at3.125–6.25 and 6.25–12.5 µg/ml in V79-MZ andV79 cells respectively. Higher concentrations caused cell cycledelay and, therefore, did not affect ploidy. BP and DMBA didnot induce a significant increase in SCE frequency at the abovedoses. 3-Methylcholanthrene tested up to its solubility limit(10 µg/ml) did not induce numerical aberrations in anycell line. The clastogen mitomycin C, tested up to 0.01 µg/ml,did not produce numerical aberrations but did significantlyincrease SCE frequency in all cell lines. The spindle poisoncolchicine, tested up to 0.1 µg/ml, induced ploidy changesin the four cell lines that showed different sensitivities.Four cell lines showed no arylhydrocarbon hydroxylase activity,and V79-MZ, but not the other cells lines, showed high glutathioneS-transferase activity. Aneuploidy induction by BP and polyploidyinduction by DMBA in the absence of S9 mix in vitro have notbeen described before, and the finding might be due to the effecton tubulin. Due to their specificity and high sensitivity, theV79-MZ and V79 cell lines might be good systems for detectinganeuploidogens ³To whom correspondence should be addressed