Figure 5.

TRAIL-induced apoptosis in Med-treated cells is mediated through DR5. (a) K562 and U937 cells were pretreated with indicated antioxidants for 1 h before Med treatment and cell lysate was prepared for western blot analysis. (b) K562 and U937 cells were pretreated with inhibitors of JNK (SP600125), p38 MAPK (SB202190), and ERK1/2 (PD98059) before Med treatment for 1 h and cell lysates were prepared for performing western blotting. (c) K562 (left) and U937 (right) cells were transfected with CHOP siRNA and then treated with Med and cell lysates were prepared for performing western blotting for DR5 antibody. (d) K562 and U937 cells were treated with TRAIL or Med or combination of Med and TRAIL or Med and TRAIL with DR5 antagonist or Med and TRAIL with DR4 antagonist or Med and TRAIL with DR4 and DR5 antagonist together and cell viability was measured as described under ‘Material and Methods'. (e) K562 and U937 cells were treated with Med or TRAIL or combination of Med and TRAIL or Med with DR4 agonist or Med and TRAIL with DR4 agonist and cell viability was measured as described under ‘Material and Methods. (f) K562 and U937 cells were treated with Med or TRAIL or Med with DR5 agonist or Med and TRAIL with DR5 agonist and cell viability was measured as described under ‘Material and Methods. Data are presented as mean±S.D. *P>0.05, **P>0.001, ***P>0.0001 in treated groups versus control group