塞来昔布诱导大肠癌细胞凋亡与细胞色素C依赖性信号途径活化相关

Induction of apoptosis by celecoxib through activation of cytochrome C pathway in HT-29 cell

目的 观察塞来昔布对大肠癌细胞株HT 2 9的凋亡诱导作用 ,并通过分析塞来昔布作用后的HT 2 9细胞的细胞色素C、Caspase 9和多聚ADP核糖多聚酶 (PARP)蛋白表达的变化 ,探讨其诱导大肠癌细胞凋亡的分子机制。方法 大肠癌细胞凋亡用吖啶橙 /溴化乙啶染色结合荧光显微镜、流式细胞仪 (FCM )技术测定 ,细胞色素C、Caspase 9和PARP蛋白表达用Western印迹技术检测。 结果 荧光染色法显示塞来昔布在 0～ 12 0 μmol/L呈浓度和时间依赖性诱导HT 2 9结肠癌细胞凋亡。FCM结果显示典型的亚二倍体“凋亡峰” ,凋亡率分别为 (7.31± 2 .37) %～ (4 8.30± 2 .86 ) %。塞来昔布诱导线粒体释放细胞色素C入胞质 ,激活Caspase 9,继而裂解活化PARP。结论 塞来昔布可诱导大肠癌细胞株HT 2 9细胞凋亡 ,其机制涉及细胞色素C依赖性凋亡调节信号通路。

Objective To study the effect of selective cyclooxygenase-2 inhibitor celecoxib on cell apoptosis of human colorectal cancer cell line HT-29 and the probable mechanism involved by detecting the expressions of cytochrome C, Caspase-9 and poly ADP-ribose polymerase(PARP) at protein level. Methods Apoptosis was determined by Acridine orange and Ethidium bromide staining under fluorescence microscope and flow cytometry. The protein expression of cytochrome C, Capsase-9 and PARP were examined by Western blotting.Results Celecoxib induced apoptosis of HT-29 human colorectal cancer cells in a concentration and time-dependent manner from 0 to 120 μmol/L. Sub-G 1 peak was detected by flowcytometry, and the apoptotic rate was between(7.31±2.37)%-(48.30 ±2.86)%. Celecoxib induced cytochrome C release into the cytosol from mitochondria, then activated Caspase-9 and consequently triggered PARP cleavage.Conclusion Celecoxib can induce apoptosis through a cytochrome C-dependent pathway in human colorectal cancer cell line HT-29.