PCNA 泛素化对Hela 细胞苯并芘损伤敏感性的影响

目的:观察PCNA泛素化修饰对Hela细胞损伤敏感性的影响。方法:Western blot法检测His-PCNA及His-mutant PCNA(mPCNA,K164R)在Hela细胞中的表达。DNA损伤剂苯并芘(BaP)和依托泊苷(VP-16)分别处理Hela细胞后,MTT法检测不同细胞系对DNA损伤药物的敏感性;Western blot法检测细胞PCNA的泛素化修饰。结果:Western blot结果显示His-PCNA和His-mPCNA在Hela细胞中稳定高表达。MTT结果显示,苯并芘损伤后,稳定高表达mPCNA的细胞系与野生型及高表达PCNA细胞系相比,其细胞存活率呈明显下降趋势,而VP-16作用后,三种细胞存活率无明显差异。Western blot结果显示苯并芘损伤可特异性诱导PCNA发生泛素化修饰。结论:苯并芘损伤能够诱导PCNA发生泛素化修饰,从而降低Hela细胞对苯并芘损伤的敏感性。

Effects of PCNA Ubiquitination on Benzopyrene(Bap)-InducedCytotoxicity in HeLa Cells

Objective: To investigate the effect of ubiquitinated PCNA on BaP induced DNA damage response.Method:The expression of the His-PCNA and His-mPCNA(mPCNA,K164R) in Hela cells were detected by Western blot.The Hela cells were dealt by using the DNA damaging agents Benzopyrene(BaP) and Etoposide(VP-16),and,the sensitivity of different cell lines was detected with MTT assay.Results: His-PCNA and His-mPCNA had stably expression in Hela cells.mPCNA-Hela cells were more sensitive to BaP induced cytotoxicity compared with the wild type Hela cells and PCNA-Hela cells.While the survival of the three kinds of Hela cells treated with VP-16 didn’t appear significant difference.DNA Damaging agents BaP could induce PCNA ubiquitination specially.Conclusions: PCNA ubiquitination even plays an important role in BaP induced damage response.Ubiqitinated PCNA may improve the survival of Hela cells treated by BaP cytotoxicity.