The p53 isoform delta133p53ß regulates cancer cell apoptosis in a RhoB-dependent manner
Fig 3
Delta133p53ß protects cancer cells from camptothecin-induced apoptosis.
(a) Apoptosis assay showing the sensitivity to 5μM camptothecin of mock-transfected (control) SW620 cells and after transfection with siRNAs against RhoB. Results are expressed as the apoptosis ratio of untreated versus camptothecin-treated cells and represent the mean ± SEM of four independent experiments; *, p<0.05. (b) Immunoblot showing RhoB downregulation in siRhoB-transfected SW620 cells compared with mock-transfected cells (control). (c) Apoptosis assay to test the sensitivity of SW480 and SW620 cells to 5μM camptothecin. Results are expressed as the percentage of apoptotic cells relative to all Hoechst-positive cells and represent the mean ± SEM of three independent experiments; *, p<0.05. (d) Apoptosis assay showing the sensitivity to 5μM camptothecin of mock-transfected (control) and SW480 cells that stably express delta133p53α, ß or γ. Results are expressed as the percentage of apoptotic cells relative to all Hoechst-positive cells and represent the mean ± SEM of three independent experiments; *, p<0.05. (e) Apoptosis assay showing the sensitivity to 5μM camptothecin of mock-transfected and SW480 cells that stably express delta133p53ß. Results are expressed as the percentage of apoptotic cells relative to all Hoechst-positive cells and represent the mean ± SEM of four independent experiments; *, p<0.05.