KLF4对结直肠癌细胞生长抑制及化疗敏感性的影响

Effect of KLF4 on viability,apoptosis of colorectal cancer cells and chemosensitivity to cisplatin

目的:探讨Krüppel样因子4(KLF4)对结直肠癌细胞活力、凋亡及顺铂化疗敏感性的影响。方法:Western blot法检测KLF4在结直肠癌Caco2、SW480和HCT116细胞中的表达。将SW480细胞分为pc DNA3. 1组(转染pc DNA3. 1空质粒)、pc DNA3. 1-KLF4组(转染构建的pc DNA3. 1-KLF4过表达质粒)和pc DNA3. 1-KLF4+顺铂组(转染pc DNA3. 1-KLF4 48 h后用1 mg/L顺铂处理细胞48 h),Western blot检测KLF4、p-IκBα、细胞周期素D1(cyclin D1)和生存素(survivin)的蛋白水平; CCK-8法检测各组细胞活力;流式细胞术检测细胞凋亡率; DCFH-DA探针检测活性氧簇(ROS)含量。结果:KLF4在结直肠癌细胞中的表达均显著低于在人结肠黏膜上皮NCM460细胞的表达(P <0. 05)。与pc DNA3. 1组相比,pc DNA3. 1-KLF4组的KLF4蛋白表达显著增高(P <0. 05),细胞活力及cyclin D1和survivin的蛋白表达均显著降低,细胞凋亡率、ROS含量及p-IκBα的蛋白表达均显著增高;而pc DNA3. 1-KLF4+顺铂组细胞活力及cyclin D1和survivin的蛋白表达均显著低于pc DNA3. 1-KLF4组,细胞凋亡率、ROS含量及p-IκBα的蛋白表达均显著高于pc DNA3. 1-KLF4组(P <0. 05)。结论:上调结直肠癌细胞KLF4基因表达可降低肿瘤细胞活力,诱导细胞凋亡,增强顺铂化疗敏感性,其机制可能与提高细胞内ROS含量及下调NF-κB信号关键分子IκBα的磷酸化水平有关。

AIM:To investigate the effect of Krüppel-like factor4(KLF4)on the viability,apoptosis and cisplatin chemosensitivity of colorectal cancer cells.METHODS:KLF4expression in colorectal cancer cell lines Caco2,SW480and HCT116was detected by Western blot.The SW480cells were divided into pcDNA3.1group(transfected with pcDNA3.1empty plasmid),pcDNA3.1-KLF4group(transfected with pcDNA3.1-KLF4expression plasmid)and pcDNA3.1-KLF4+cisplatin group(treated with1mg/L cisplatin for48h after pcDNA3.1-KLF4was transfected into SW480cells).The protein levels of KLF4,p-IκBα,cyclin D1and survivin were determined by Western blot.The cell viability was measured by CCK-8assay.The apoptotic rate was analyzed by flow cytometry.The content of reactive oxygen species(ROS)was measured by DCFH-DA probe.RESULTS:The expression of KLF4in the colorectal cancer cells were significantly lower than that in the human colon mucosal epithelial NCM460cells(P<0.05).Compared with pcDNA3.1group,the protein expression of KLF4in pcDNA3.1-KLF4group was significantly increased(P<0.05).Compared with pcDNA3.1group,the cell viability and the protein expression of cyclin D1and survivin were significantly decreased,and the apoptotic rate,the content of ROS and the protein level of p-IκBαwere significantly increased in pcDNA3.1group(P<0.05).Compared with pcDNA3.1-KLF4group,the cell viability and the expression of cyclin D1and survivin proteins were significantly decreased,and the apoptotic rate,the content of ROS and the protein level of p-IκBαwere significantly increased in pcDNA3.1-KLF4+cisplatin group(P<0.05).CONCLUSION:Upregulation of KLF4gene expression in colorectal cancer cells reduces the cell viability,induces apoptosis and increases the chemosensitivity of the cells to cisplatin.The mechanism may be related to the enhancement of intracellular ROS content and down-regulaton of the phosphorylation level of IκBα,the key molecule of NF-κB signaling pathway.