Effect of JNK pathway on the upregulation of DR4 or DR5, and cell death by snake venom toxin. a, Effect of snake venom toxin on the expression of MAPK proteins in colon cancer cells. HCT116 cells and HT-29 cells were treated with snake venom toxin for 24 h and whole cell extracts were analyzed by western blotting using the relevant antibodies. b, Effect of SP600125 on the cell viability in snake venom toxin treated cancer cells. Cells were pretreated with SP600125 (0, 5, 10 μM) for 1 h and then treated with snake venom toxin for 24 h. The results were expressed as a percentage of viable cells. c, Effect of JNK inhibitor (SP600125) on the expression of death receptors. Cells were pretreated with SP600125 (10 μM) for 1 h, and then cells were treated with snake venom toxin for 24 h, and whole cell extracts were analyzed by Western blotting using DR4, DR5, p-JNK and β-actin antibodies. Each band is representative for three experiments. Columns, means of three experiments, with triplicates of each experiment; bars, SD. *, p <0.05, significantly different from non treated control group. #, p <0.01 significantly different from SVT-treated group.