Fig. 4

CHOP mediated the DR5 upregulation by EEDS. a A549 cells were treated with a combination of EEDS (E, 5 μg/mL) and TRAIL (T, 100 ng/mL) for 24 h, and the intracellular expression levels of DR5 and CHOP were determined by western blot analysis. b A549 cells were transiently transfected with control or CHOP siRNA. After 48 h, the cells were treated with 5 μg/mL EEDS for 24 h. Whole cell lysates were prepared, and the intracellular expression levels of DR5 and CHOP were determined by western blot analysis. β-actin was included as a loading control. c CHOP knockdown inhibited EEDS-enhanced TRAIL toxicity. A549 cells were transfected with control or CHOP siRNA for 48 h and then treated with a combination of EEDS (5 μg/mL) and TRAIL (100 ng/mL). Cell viability was determined after 24 h of drug treatment as previously described. The data are presented as the mean ± SD of triplicate experiments. *P <0.05. d Schematic of the EEDS-mediated sensitization of A549 lung cancer cells to TRAIL