FIG. 4.

Knockdown of death receptors abrogates Zyflamend's ability to enhance TRAIL-induced apoptosis. (A) HCT-116 cells were transfected with DR5 siRNA, DR4 siRNA, alone or in combination, and control siRNA. After 48 h, cells were treated with 250 μg/mL Zyflamend for 24 h, and whole-cell extracts were analyzed by Western blotting using DR5 and DR4 antibodies. (B) After 48 h of transfection with siRNA, cells were pre-treated with 100 μg/mL Zyflamend for 12 h and then incubated with 25 ng/mL TRAIL for 24 h. Cell death was determined by the live/dead assay. (To see this illustration in color the reader is referred to the web version of this article at www.liebertonline.com/ars).