Figure 4.

RES/DDP combination treatment activates endoplasmic reticulum stress-mediated apoptotic signaling pathways. (A-C) The protein expression levels of GRP78, PERK, p-eIF2α, eIF2α, CHOP and caspase-12 were determined by western blotting. (D) Fluo-4 AM probe and flow cytometry were used to detect intracellular Ca²⁺ concentrations after RES (20 µM) and DDP (1 µg/ml) cotreatment for 48 h. (E) The median Fluo-4 fluorescence intensities are presented. The data are presented as the mean ± SD (n=3). *P<0.05, **P<0.01 and ***P<0.001. RES, resveratrol; DDP, cisplatin; GRP78, glucose-regulated protein 78; PERK, PRKR-like ER kinase; p-eIF2α, phosphorylated eukaryotic translation initiation factor 2α; CHOP, CCAAT/enhancer binding protein homologous protein; CTRL, control; COM, combination treatment.