[Studies on mutagenicity of polycyclic aromatic hydrocarbon-DNA adduct]

Mutagenic effect of polycyclic aromatic hydrocarbon (PAH)-DNA adduct was studied to explore mechanism of carcinogenecity of PAH. Adduct was formed by chemical group protection and nucleophilic displacement methods with modification of deoxyadenosine by PAH-dihydrodiol epoxide. Partial analogous sequence of human protooncogene ras (H-ras) containing mutagenic hotspot 61 codon (CAG) was synthesized by a DNA assembler and DNA was duplicated with a template of partial analogous sequence containing adduct protooncogene. Results showed that PAH-DNA adduct could obviously affect the process of DNA duplication, cause interruption of duplication of DNA or translesional bypass, lower fidelity of duplication, and induce misincorporation of bases in corresponding locus of the adduct, with point mutation of transversion (from A-T to T-A).