Fig. 6

HIF-1a expression in NSCLCs following heat treatment is regulated through both the AKT and ERK signaling pathways. NCI-H1650-b sublines are seeded and pretreated with different concentrations of heregulin and then exposed to 1 % oxygen. Expression levels of AKT, ERK, phosphorylated AKT, and phosphorylated ERK were determined by western blot analysis. a After treatment with heregulin, AKT and ERK total protein expression levels showed no obvious change (^* p > 0.05 between different groups), but p-AKT and p-ERK were significantly up-regulated (^※ p < 0.05 between different groups). b NCI-H1650 –b cells are seeded and pretreated with wortmannin and PD98059, then treated with heregulin. Cells are harvested and protein is detected by western blotting. When treated with heregulin, HIF-1a expression is significantly up-regulated (^▲ p < 0.05 heregulin group vs control group), but is inhibited after co-treatment with wortmannin or PD98059 (^* p < 0.05 heregulin group vs heregulin + wortmannin group or heregulin + PD98059 group). Total AKT and ERK protein showed no significant changes, whether treated singly or co-treated with wortmannin or PD98059, according to the analysis of optical density (^※ p > 0.05 heregulin group vs control group, heregulin + wortmannin group or heregulin + PD98059 group). However, p-AKT and p-ERK expression was up-regulated when cells were treated with heregulin, but was inhibited after co-treatement with wortmannin or PD98059 (^# p < 0.05 heregulin group vs control group, heregulin + wortmannin group or heregulin + PD98059 group)