Figure 3

Involvement of JNK activation in denbinobin-induced apoptosis in A549 cells. (A) Cells were pretreated with SP600125 (10 μM) for 30 min before incubation with 20 μM denbinobin for 24 h, and then apoptosis was detected using flow cytometry of PI-stained cells as described in "Materials and methods". Each column represents the mean ± SEM of at least three independent experiments. *p < 0.05, compared to the denbinobin group. Cells were treated with 20 μM denbinobin for the indicated time intervals. Cell lysates were then prepared and subjected to JNK phosphorylation (B) or JNK kinase activity (C) as described in "Materials and methods". Equal loading in each lane is demonstrated by similar intensities of JNK. Compiled results are shown in the lower panel. Each column represents the mean ± S.E.M. of at least three independent experiments. * p < 0.05, compared to the control group.