PEOL induced ROS-dependent ER stress.

<p>HCT116 and HCT8 cells were treated with PEOL for 24 h then eIF2α phosphorylation and CHOP mRNA expression were determined by western blotting (A,B) and Real-time PCR (C,D), respectively. HCT116 were treated incubated with NAC (0.5 mM) before PEOL treatment for 24 h, then CHOP mRNA expression (E) or Annexin V and 7-AAD labeling were performed (F). Data represent means ± SEM (n = 6). *,**,*** represent <i>p</i> < 0.05, <i>p</i> < 0.01, <i>p</i> < 0.001 respectively as compared to untreated cells.‡‡‡ represent <i>p</i> < 0.001 for Annexin V+ comparison between NAC-treated and untreated cells. <i>p</i> values were obtained by one-way ANOVA, followed by Fisher’s LSD test.