Figure 5

Effect of enforced overexpresson of XIAP IRES RNA on cell apoptosis. A and B, SK-N-SH (wt-p53) and LA1-55N (p53-null) cells that were stably transfected with either XIAP IRES RNA or XIAP non-IRES RNA (control) were treated with different dose of siXIAP or control siRNA for 48 h, and cell survival was determined by WST assays. Data represent the mean percentage (±SD) of cell survival from three independent experiments, *p < 0.05 (A), p > 0.5 (B). C, time-course of apoptosis induced by IR in SK-N-SH and LA1-55N cells that were stably transfected with either XIAP IRES RNA or XIAP non-IRES RNA. Cells were treated with 10 Gy IR for the indicated time points, and then the apoptotic cells were detected by annexin-V staining and flow cytometry. Data represent the mean percentage of annexin-V positive cells from three independent experiments, bars ± SD, *p < 0.01, **p < 0.05. D, same SK-N-SH and LA1-55N cells transfected with RNA as described above were treated with 10 Gy IR or 200 nM siXIAP alone or their combination for 24 h, and then apoptosis was detected as in (C), *p < 0.01, **p > 0.5.