KLF5对吉西他滨诱导的肺腺癌细胞凋亡的促进作用及其机制

目的 研究krüppel-like factor 5基因（KLF5）的表达对吉西他滨介导的肺腺癌细胞凋亡的影响及分子机制。 方法 在体外培养的肺腺癌细胞H441中，分别转染KLF5表达质粒和空载体对照质粒培养68 h后，加入100 nmol/L的凋亡诱导药物吉西他滨处理4 h，使用细胞计数和流式细胞术方法检测细胞增殖和凋亡； Western blot检测KLF5蛋白的表达，RT-PCR检测KLF5及凋亡相关基因CD95和BAX的表达；免疫荧光染色比较凋亡相关蛋白Caspase 3的表达。 结果 Western blot结果证明KLF5转染成功。无吉西他滨诱导情况下，KLF5高表达对H441细胞的凋亡无显著影响，CD95和BAX基因的表达差异无统计学意义；吉西他滨诱导情况下，与对照组相比，KLF5高表达的H441细胞中凋亡细胞比例增加（P<0.05），CD95和BAX基因的表达上升（P<0.05），Caspase 3的表达上调。 结论 在吉西他滨诱导下，体外KLF5高表达促进肺腺癌细胞H441的凋亡。其机制可能是通过抑制细胞增殖和修复激活Caspase 3、CD95和BAX等细胞凋亡通路相关蛋白实现。

Promotive Effect and Its Molecular Mechanism of KLF5 on Gemcitabine-induced Apoptosis in Human LungAdenocarcinoma Cell Line H441

Objective To investigate the effects of krüppel-like factor 5 (KLF5) overexpression on gemcitabine (GEME)-induced lung adenocarcinoma cell apoptosis and its molecular mechanisms. Methods Lung adenocarcinoma cell line H441 were transfected with KLF5 plasmid or control plasmid. 68 h later, cells were treated with 100 nmol/L GEME for 4 h，then cell number counting and flow cytometry were applied to detect cell proliferation and apoptosis; Western blot were used to analyse the expression level of KLF5, RT-PCR were used to analyse the KLF5gene, apoptosis-related genes CD95 and BAX; Immunofluorescence staining was performed to detect the expression level of apoptosis-related protein Caspase 3. Results The overexpressions of KLF5 protein were detected in cultured- lung adenocarcinoma cell line H441 cells when KLF5 plasmids were transfected 68 h. Further flow cytometry, overexpression of KLF5 in H441 cell line affected the biological process of apoptosis significantly. No significant changes of apoptosis and expression level of CD95 and BAXin H441 cells were observed by KLF5 overexpression without GEME treatment (P >0.05). Under GEME induction, the proportion of apoptotic cells and expression level of CD95 and BAXwere increased significantly in H441 cells by KLF5 overexpression, compared with that of control (P <0.05); The overexpression of KLF5 restrained the proliferation of H441 cells; Immunofluorescence staining of Caspase 3 was also enhanced after KLF5 overexpression. Conclusion Under GEME induction, the overexpression of KLF5 promoted the apoptosis of lung adenocarcinoma cell line H441 in vitro, possibly through the inhibition of cell proliferation and repair/activation of apoptosis pathway proteins, such as Caspase 3, CD95 and BAX.