Abstract:

OBJECTIVE: To discuss the interaction between autophagy and endoplasmic reticulum stress in human gastric cancer SGC-7901 cells treated with vitamin E succinate (VES). METHODS:Human gastric cancer SGC-7901 cells were treated with VES of different doses (0, 5, 10, 15, 20 μg/mL), then after 24 h laser confocal microscope was used to study fluorescence intensity and distribution of the autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3). Western blot was used to evaluate the level of endoplasmic reticulum stress markers glucose regulative protein 78(GRP78), glucose regulative protein 94(GRP94) and LC3, Beclin-1. SGC-7901 cells were pre-treated with autophagy inhibitors, 3-methyladenine(3-MA) and chloroquine (CQ), inhibitor of endoplasmic reticulum stress, 4-phenylbutyric acid(4-PBA), then human gastric cancer SGC-7901 cells were treated with 20 μg/mL VES for 24 h. Western blot evaluated the level of GRP78, GRP94, LC3 and Beclin-1. RESULTS:With increasing doses of VES, the LC3 in cells began to gather and intensity, GRP78 and GRP94 were decreased, then increased again and peaked at 24 h. The levels of GRP78 and GRP94 in VES+3-MA group and VES+CQ group were significately higher compared with VES alone (all P<0.05). The levels of LC3 and Beclin-1 in VES+4-PBA group were higher compared with VES alone(both of P<0.05). CONCLUSION:In VES-treated human gastric cancer cells, the autophagy and endoplasmic reticulum stress could interact and regulate each other.

Key words: vitamin E succinate, endoplasmic reticulum stress, autophagy, gastric cancer cells