engleski

Transgenic Chinese hamster ovary (CHO) cells expressing the yeast apurinic/apyrimidinic endonuclease gene (APN1) are more resistant to DNA damaging agents

Although APE cDNA was markedly expressed on RNA and protein level, the enzymatic activity in nuclear extracts of CHO-9-APE transfectants was equal to the activity of the control cell line, transfected only with pSV2neo. The transfectants were as sensitive as the control to the cell killing and clastogenic effect of methyl methanesulfonate (MMS) and hydrogen peroxide (H2O2). On the contrary, cells transfected with the yeast APN1 gene, CHO-9-APN1, expressed higher AP endonuclease activity in vitro and reacted clearly more resistant to the cytotoxic and clastogenic effect of the used mutagens. The excision repair capacity and mutagen resistance in mammalian cells can be enhanced by introducing the yeast DNA repair gene, APN1. Increased repair of AP sites protects CHO cells against different classes of mutagens. AP sites are not only cytotoxic but also clastogenic lesions.

base excision repair ; AP endonucleases ; cellular defence ; genotoxic agents

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