Fig. 3.

Hypoxia activates the PERK pathway in HCC cells. a HepG2 cells were cultured in normoxia or hypoxia for 24 h or 48 h. The PERK targets, GRP78, ATF4, CHOP and GADD34 mRNA were detected by Real-time PCR analysis. b Expressions of phospho-eIF2α, eIF2α, ATF4, and CHOP protein in HepG2 cells were detected using Western blotting. All experiments were repeated three times with similar results. c Densitometry analysis of the ratio of phosphorylated eIf2α to total eIf2α bands normalised to tubulin and relative to the corresponding control. Quantitative results of the phosphorylation of eIf2α are presented as the mean ± SD. d Real-time PCR analysis of the PERK targets in Huh7 and e Hep3B cells. *p < 0.05, **p < 0.01, ***p < 0.001