维生素E琥珀酸酯通过内质网应激诱导胃癌SGC-7901细胞凋亡的研究

目的:探讨内质网应激在维生素E琥珀酸酯(vitamin E succinate,VES)诱导人胃癌SGC-7901细胞凋亡过程中的作用。方法:分别采用Western blotting和RT-PCR检测VES不同剂量(0、5、10和20μg/ml)处理SGC-7901细胞24 h和20μg/ml VES处理SGC-7901细胞不同时间对内质网应激标志物葡萄糖调节蛋白(glucose regulative protein,GRP)GRP78、GRP94和内质网应激凋亡途径关键因子C/EBP同源蛋白(C/EBP-homologous protein,CHOP)的蛋白和mRNA表达的影响;进一步采用RNA瞬时干扰阻断CHOP的表达后用20μg/ml VES作用SGC-7901细胞24 h,采用DAPI染色法观察细胞凋亡的改变。结果:20μg/ml VES组在mRNA水平卜均诱导GRP78、GRP94和CHOP的表达增加;在蛋白水平上20μg/ml VES显著增加GRP78和CHOP的表达,GRP94表达先降低,而后又升高;阻断CHOP后VES诱导的细胞凋亡由46.3%降低为27.9%(P0.05)。结论:内质网应激可能参与了VES诱导的SGC-7901细胞凋亡。

Vitamin E succinate-induced apoptosis of SGC-7901 cells via endoplasmic reticulum stress

OBJECTIVE：To investigate the roles of endoplasmic reticulum stress（ERS） in vitamin E succinate（VES）-induced apoptosis in human gastric cancer SGC-7901 cells.METHODS：SGC-7901 cells were treated with VES at 5,10 and 20μg/ml and at 3μg/ml tunicamycin（TM） for 24 h or at 20μg/ml for up to 24 h.Glucose regulative protein 78（GRP78）,GRP94 and C/EBP-homologous protein（CHOP） were explored using Western blotting and RT-PCR.When the cells were transfected with CHOP siRNA,apoptosis was assessed by DAPI staining. RESULTS：The mRNA levels of GRP78,GRP94,CHOP and protein levels of GRP78,CHOP increased in 20μg/ml VES-treated cells.GRP94 protein levels were decreased at 6 h,12 h and 18 h,then increased again and reached the top level at 24 h.Downregulation of the CHOP mRNA reversed VES-induced apoptosis（P〈0.05）.CONCLUSION： Endoplasmic reticulum stress might be involved in VES-induced apoptosis in human gastric cancer SGC-7901 cells.