대사활성계 존재하의 포유동물 배양세포에 있어 DNA 사 절단과 복제에 미치는 벤조피렌의 영향 = Effects of Benzo (a) Pyrene on DNA Strand Breaks and Replication in the Presence of Metabolic Activation System in Mammalian Cells

다국어 초록 (Multilingual Abstract)

DNA single strand breaks were induced by BP treatment in a small extent in CHO-K1 cells, but none in XP20S cells (complementation group A). By coculturing with mouse embryo fibroblast cells, however, CHO-K1 cells showed a significant formation of strand breaks and their accumulation by post-incubation with hydroxyurea and ara-C in a dose dependant manner, which was not seen in XP20S cells, indicating the UV-mimetic nature of BP-induced DNA damages. The pattern of DNA replication in CHO-K1 cells was different from that in XP20S cells by 24hr treatment of BP according to their repair abilities. The dose dependant inhibition of replicon initiation at 12hr exposure of CHO-K1 cells to BP changed to the blocking of chain elongation by 24hr exposure period. Inhibition of different modes of DNA replication was demonstrated when metabolic activation system was introduced into XP20S cells. All these results suggested that lower doses and shorter times were required for both strand break formation and inhibition of replication by the presence of metabolic activation system than by the absence of it during the exposure to BP, and that BP-DNA adducts were efficiently removed in CHO-K1 cells but not in XP20S cells resulting in differences in the single strand breaks or in the mode of inhibition of DNA replication.