Fig. 4

Thapsigargin could not mimic the effects of tunicamycin on MDR GC cells. a Concentration-survival curves of GC cells treated with Tg or Tu (wide dose range) for 48 h. Tg, thapsigargin. b Expressions of UPR-related proteins in GC cells after Tg treatment (2 μg/ml) for 48 h determined by WB. All proteins were normalized to β-actin. c The effects of Tg on the chemosensitivity of GC cells after treatment for 48 h. ns, non-significant; *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 (green/red, +Tg 0.5/2 versus standard, respectively)