表没食子儿茶素没食子酸酯调控食管癌细胞线粒体膜电位诱导细胞凋亡作用研究

Epigallocatechin-3-gallate induced Ec9706 cell apoptosis by regulating the mitochondrial transmembrane potential

目的探讨表没食子儿茶素没食子酸酯(epigallocatechin-3-gallate,EGCG)调控食管癌细胞Ec9706线粒体膜电位诱导细胞凋亡作用。方法不同浓度(100、200、300 mg/L)EGCG作用Ec9706细胞24 h后,Annexin V/PI双标流式细胞术方法检测细胞凋亡水平;流式细胞术检测细胞线粒体膜电位;Western Blot方法检测细胞中Caspase-3蛋白表达水平,0.9%氯化钠溶液代替EGCG作为对照组。结果 100、200、300 mg/L EGCG作用Ec9706细胞24 h后,与对照组相比Ec9706细胞凋亡率显著增高(P<0.01),300 mg/L EGCG组细胞凋亡率显著高于100、200 mg/L EGCG组(P<0.01)。EGCG可显著降低细胞线粒体膜电位(P<0.01),且具有剂量依赖性。western-blot结果显示,EGCG组与对照组相比Caspase-3蛋白表达水平显著增高(P<0.05)。结论 EGCG具有诱导食管癌Ec9706细胞凋亡作用,其作用机制可能与调控线粒体膜电位引起内源性细胞凋亡有关。

Objective To investigate the effects of and action mechanism of epigallocatechin-3-gallate（ EGCG） in inducing cell apoptosis of esophageal cancer（ Ec9706 cell） through regulating mitochondrial transmembrane potential.Methods The Ec9706 cells were treated by different doses of EGCG（ 100,200,300 mg / L） for 24 h,then the cell apoptosis rates were detected by Annexin V / PI staining. The mitochondrial transmembrane potential was measured by flow cytometry.Moreover the expression levels of Caspase-3 protein were detected by Western Blot. Normal saline instead of EGCG was used as control group. Results After Ec9706 cells were treated by different doses of EGCG（ 100,200,300 mg / L） for 24 h,the cell apoptosis rates in EGCG groups were significantly increased,as compared with those in control group（ P〈0. 05）,moreover,which in 300 mg / L EGCG group were significantly higher than those in 100 mg / L and 200 mg / L EGCG group（ P〈0. 01）.EGCG could obviously decrease mitochondrial transmembrane potential（ P〈0. 01）,with a dose- dependent manner. The results by Western Blot showed that the expression levels of Caspase-3 protein in EGCG groups were significantly increased,as compared with those in control group（ P〈0. 05）. Conclusion EGCG has the effects of inducing Ec9706 cell apoptosis,and its action mechanism may be correlated to regulating mitochondrial transmembrane potential to induce endogenous cell apoptosis.