Environmental Toxic Agents on Genetic Material and Cellular Ativity V. The Roles of DNA Polymerases on Mutagen-Induced DNA Repair Synthesis in Relation to Cell Cycle in Chinese Hamster Ovary Cells

환경성 유해요인이 유전물질과 세포활성에 미치는 영향 V. CHO세포에서 세포주기에 따라 돌연변이원에 의해 유발된 DNA회복합성에 미치는 DNA중합효소의 역할

Chinese hamster ovary (CHO)-K1 cells echibited a differential sensitivity in the process of DNA repair synthesis induced by ethyl methanesulfonate (EMS) or bleomycin (BLM) in relation to cell cycle. Two assays were employed in this study: alkaline elution and unscheduled DNA synthesis. The post-treat-ment with aphidicolin (APC), an inhibitor of DNA polymerase alpha, inhibited DNA repair synthesis induced by EMS in G2 phase, while APC did not show any effect on BLM-induced DNA repair synthesis in all phases. On the other hands, the 2', 3'-dideoxythymidine (ddTTP), an inhibitor of DNA polymerase beta, inhibited DNA repair synthesis induced by EMS or BLM in both of G1 and G2 phases. These results suggested that the involvement of DNA polymerase alpha and beta in DNA repair was dependent on cell stage or used chemical agent.