N-甲基-N'-硝基-N-亚硝基胍对人支气管上皮16HBE细胞周期进程的影响

The effects of N-methyl-N′-nitro-N-nitrosoguanidine on cell cycle progression in human bronchial epithelial(16HBE) cells

目的探讨N-甲基-N'-硝基-N-亚硝基胍(MNNG)对人支气管上皮16HBE细胞周期进程的影响及相关分子机制。方法 16HBE细胞经MNNG处理后,噻唑蓝(MTT)法检测MNNG对16HBE细胞增殖的影响,PI染色检测细胞凋亡,Hoechst 33342和PI双染检测细胞坏死,流式细胞术检测细胞周期分布,在周期变化明显的时点应用蛋白免疫印记检测周期相关蛋白含量变化。结果 MNNG能够剂量依赖性的抑制细胞增殖和诱导凋亡,亚致死剂量的MNNG使细胞引起明显的S期和G2/M期阻滞,同时细胞周期相关蛋白p-Cdk2(Thr160)和Cdc25A含量下降明显。结论 MNNG通过降低细胞p-Cdk2(Thr160)和Cdc25A的含量诱导16HBE细胞发生S期和G2/M期阻滞。

Objective To explore the effects of N-methyl-N′-nitro-N-nitrosoguanidine（MNNG） on cell cycle progression and related molecular mechanisms in human bronchial epithelial（16HBE） cells.Methods The 16HBE cells were exposed to MNNG.After the treatment,the cell proliferation was measured by the MTT assay.The cells were stained with Propidium Iodide（PI） for the detection of apoptosis and stained with both Hoechst 33342 and PI for the detection of necrosis.The cell cycle distribution was studied by flow cytometry,and the cellular levels of cell cycle-related proteins between different checkpoints were compared by western blot.Results MNNG suppressed cell proliferation and induced apoptosis in 16HBE cells in a dose-dependent manners.Within the sublethal dose,MNNG significantly induced S and G2/M arrest.The levels of p-Cdk2（Thr160） and Cdc25A were significantly decreased after treatment of MNNG.Conclusion MNNG could induce S and G2/M arrest by decreasing the levels of p-Cdk2（Thr160） and Cdc25A in 16HBE cells.