Figure 7
Bim expression is involved in denbinobin-induced apoptosis in A549 cells. (A) Following transfection with control siRNA or bim siRNA for 6 h, cells were treated with vehicle or 20 μM denbinobin for another 24 h. The DNA content was then analyzed by flow cytometry of PI-stained cells as described in "Materials and methods". Each column represents the mean ± S.E.M. of at least three independent experiments. * p < 0.05, compared to the control siRNA group in the presence of denbinobin. Cells were incubated with 20 μM denbinobin (B) or 5 mM H2O2 (C) for the indicated intervals, pretreated with 1 mM NAC, 100 μM GSH, or 10 μM SP600125 (D), or transiently transfected with pcDNA, ASK1DN, JNK1DN, or JNK2DN for 6 h (E). Cells were then treated with vehicle or 20 μM denbinobin for 2 h. Following treatment, RNA was collected to assess bim expression by semiquantitative RT-PCR as described in "Materials and methods". Samples were normalized for β-actin intensities. Typical traces are representative of three experiments with similar results.