Abstract: 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 20 μg/ml and at 3 μg/ml tunicamycin (TM) for 24 h or at 20 μg/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 20 μg/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.

Key words: endoplasmic reticulum stress, vitamin E succinate, apoptosis