Figure 4.

Effect of PDE5 knockdown on vincristine-induced cell-cycle distribution and protein expression. PC-3 cells were transfected with control or PDE5 siRNA as described in the Materials and methods section. After the transfection, the cells were incubated in the absence or presence of vincristine (10 nM) for 24 h and then the cells were harvested and lysed for the detection of protein expression by Western blot analysis (A) or the cells were harvested for propidium iodide staining to analyze the distribution of cell populations at various phases using FACScan flow cytometric analysis (B). Data are expressed as mean ± SEM of four independent determinations. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 compared with vincristine alone at siControl group.