Figure 3. Mono-Pt but not cisplatin induces a nonapoptotic cell death in human ovarian carcinoma Caov-3 cells. (A) Caov-3 cells were treated with 10 μM Mono-Pt or 50 μM cisplatin for indicated time, then stained with TUNEL-FITC and subjected to flow cytometric assay. Data represent mean ± SEM of three different experiments. *p < 0.05, **p < 0.01, as compared with untreated group. (B) Caov-3 cells were treated with 10 μM Mono-Pt or 50 μM cisplatin for 36 h, then stained with DAPI and TUNEL-FITC, and subjected to immunofluorescence imaging. Cells treated with DNase I (1 μg/ml) were used as positive control. The results shown are one of three different experiments. Scale bar: 10 μm. (C) Expression of cleaved CASP3 in Caov-3 cells. Cells were treated with Mono-Pt or cisplatin for 24 h, and then subjected to western blotting. The results shown are representative of three different experiments. (D) CASP3 activity in Caov-3 cells. Cells were treated with 10 μM Mono-Pt or 50 μM cisplatin for indicated time, and then subjected to CASP3 activity analysis. Data represent mean ± SEM of three different experiments. *p < 0.05, **p < 0.01, as compared with untreated group. (E) Mono-Pt-induced cell death was caspase-independent. Caov-3 cells were pretreated with different concentrations of zVAD.fmk for 6 h, and then incubated with 10 μM Mono-Pt or 50 μM cisplatin for 48 h. Cell death was assessed by trypan blue dye exclusion assay. Data represent mean ± SEM of three different experiments. *p < 0.05, **p < 0.01, as compared with the zVAD.fmk-untreated group.