Fig. 6.

CHOP up-regulation contributes to CPA induced DR5 up-regulation and TRAIL sensitivity in prostate cancer cells. a DU145 cells were transfected with control siRNA or CHOP siRNA for 24 h, and then treated without or with 50 μM CPA for 6 and 30 h. Cells were then harvested and subjected to western blot analysis. A representative western blot result for the indicated proteins of three separate experiments is shown. b-e DU145 cells transfected with control siRNA or CHOP siRNA were treated without or with 50 μM CPA for 24 h, followed by 6 h of treatment without or with 50 ng/ml TRAIL. Cells were then harvested and subjected to western blot analysis. A representative western blot result for the indicated proteins is shown in b. The relative DR5 protein level and cleavage of PARP were quantitated and are shown in c and d, respectively. β-actin was used as a loading control. Data shown are means ± S.E. (n > 3) with **p < 0.01. (E) Apoptosis was measured by the annexin V/PI flow cytometry method. Left panel, representative flow cytometry histograms of apoptosis assay; right panel, statistical analysis of results from three independent experiments. Data are means ± S.E. with *p < 0.05