苯并(a)芘对HELF细胞S期细胞周期相关蛋白的作用

Effect on the cell cycle proteins of arrested S phase cells in human embryo lung fibroblasts cells induced by benzo(a) pyrene

目的观察由于苯并(a)芘(Ba P)作用阻滞于S期的人胚肺成纤维细胞(HELF)的细胞周期蛋白和关卡蛋白表达水平的改变,探讨Ba P影响细胞周期的作用机制。方法 5μmol/L Ba P处理4 h,于处理后24 h收获细胞,利用流式细胞术对Ba P作用后的G0/G1期和S期细胞进行分选,Western blot方法分析相关蛋白表达水平的变化。结果Ba P作用HELF后,在总细胞群中和分选获得的S期细胞中均发现Chk1磷酸化水平升高,Cdc25A的表达水平降低;只在分选获得的S期细胞中,发现Cyclin E表达水平降低,CDK2和p53的表达水平升高。结论 Ba P通过启动Chk1-Cdc25A和p53两条信号转导通路共同作用于Cyclin E/CDK2,从而引发HELF细胞发生S期阻滞。

Objective To observe the cell cycle proteins of arrested S phase cells in human embryo lung fibroblasts cells（HELF）caused by benzo（a） pyrene（BaP） and to provide clues to explore molecular mechanism of carcinogenesis induced by BaP. Methods After exposure with 5 μmol/L BaP for 4 h,the HELF cells were harvested for cell cycle sort and western blot analysis at 24 h. Results After treatment of BaP,phosphorylated Chk1 level increased and Cdc25 A expression level decreased in both total cell group and the sorted S phase cell group. However,we only observed that Cyclin E decreased and CDK2 and p53 increased in the sorted S phase cell group. Conclusion The co-effect of Chk1-Cdc25 A and p53 on Cyclin E/CDK2 compound participated in the S-phase arrest induced by BaP in HELF cells.