Figure 4.

p53 inhibition attenuated PAB-induced senescence in A549 cells. (A–D) A549 cells were transfected with control or p53 siRNA for 24 h. (A) Western blot analysis was utilized to detect the transfection efficiency. (B) The cells were stained with PI and measured by flow cytometry. The ratios of the M1, M4 and M5 gated cells were calculated as the subG₁, G₂/M and multinucleation ratio, respectively. (C) The SA-β-Gal staining was used to examine the percentage of senescent cells. The ratio of the SA-β-Gal positive cells is shown. (D) The protein levels of p53, p-p53 (Ser 15), p21 and caspase-3 were evaluated by Western blot. (E, F) A549 cells were transfected with control or p21 siRNA for 24 h. (E) The senescent cells were determined using SA-β-Gal staining. The ratio of the SA-β-Gal positive cells is exhibited. (F) Western blot was utilized to examine the expression of p53, p-p53 (Ser 15), p21 and caspase-3. The data are presented as the mean±SD of three independent experiments. ^*P<0.05 vs PAB-treated group.