Carcinogen-mediated induction of SV40 DNA amplification is enhanced by acrylamide in Chinese hamster CO60 cells

The exposure of SV40-transformed Chinese hamster cells (line CO60) to 50-150 micrograms/ml of monomeric acrylamide for 24 h resulted in a very weak induction of the amplification of the SV40 DNA inserts as measured by in situ hybridization with radioactive SV40 DNA as probe. The weak SV40 DNA amplification observed might result from a weak DNA-damaging activity as biologically illustrated by the capacity of high concentrations of acrylamide to irreversibly inhibit the DNA synthesis rate of CO60 cells. Moreover, acrylamide synergistically enhanced both the cytotoxicity and the induction of SV40 DNA synthesis by the carcinogens ethylmethane sulfonate, benzo[a]pyrene, mitomycin C, 4-nitroquinoline-1-oxide, 8-azaguanine and 5-fluorodeoxyuridine. Although a weak inducer of SV40 DNA amplification by itself, acrylamide potentiated the genotoxicity of a series of chemical carcinogens. This finding should be taken into consideration when assessing the risk of this widely used chemical.