Nitrobenzo[a]pyrene-induced DNA amplification in SV40-transformed Chinese hamster embryo cells

Nitrobenzo[a]pyrenes (NBaPs) are ubiquitous environmental pollutants that produce mutations in Salmonella typhimurium and Chinese hamster ovary cells. In this study, 1-, 3-, and 6-NBaP induced amplification of SV40 DNA sequences in an SV40-transformed Chinese hamster embryo cell line which is sensitive to DNA amplification by various known carcinogens. Of the three isomers, 3-NBaP produced the highest level of gene amplification, which was 4.8 relative to untreated controls at a dose of 5 micrograms/ml. Considering the relationship between gene amplification and tumorigenesis, it seems prudent to carry out a more exhaustive analysis of the carcinogenic potential of these agents.