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(P0.05).CONCLUSION: Endoplasmic reticulum stress might be involved in VES-induced apoptosis in human gastric cancer SGC-7901 cells.