Figure 1
The effects of NSC109268 on the sensitivity of parental (2008) and cisplatin-resistant (2008/C13*) ovarian cancer cells to cisplatin. Cells were treated without (open circle) or with 2 μM NSC109268 (black circle) and varying concentrations of cisplatin for 72 h. Cell survival was determined by the MTT assay. The control values were based upon the results obtained in the absence of any drug but in the presence of vehicle or 2 μM NSC109268. Each value represents the mean ± SD of four determinants from a single microtiter plate. The results are representative of three independent experiments.
Figure 2
The effects of NSC109268 on the sensitivity of parental (HeLa) and cisplatin-resistant (HeLa/CP) human cervical carcinoma cells to cisplatin. Cells were treated without (open circle) or with 1 μM (black square), 2 μM (black triangle) or 3 μM (black circle) NSC109268 and varying concentrations of cisplatin for 72 h. Cell survival was determined by the MTT assay. The control values were based upon the results obtained in the absence of any drug but in the presence of vehicle or NSC109268. Each value represents the mean ± SD of four determinants from a single microtiter plate. The results are representative of three independent experiments.
Figure 3
Effect of cisplatin on induction of p53 and cleavage of PARP. Cells were treated with indicated concentrations of cisplatin for 24 h. Western blot analysis was performed with total cell lysates using indicated antibodies. Actin was used to control for loading differences.
Figure 4
Effect of NSC on p53 induction and cleavage of PARP. Cells were treated with or without 2 or 3 μM NSC109268 and 1 μM (2008) or 40 μM cisplatin (2008/C13*) for 24 h or 48 h. Western blot analysis was performed with total cell lysates using indicated antibodies. Actin was used to control for loading differences.
Figure 5
Effect of NSC on cisplatin-induced cell death. Cells were treated with or without 2 or 3 μM NSC109268 and 1 μM (2008) or 40 μM cisplatin (2008/C13*) for 48 h. Following incubation, cells were stained with Yo-Pro-1 and PI as described in the Methods. Fluorescent staining was visualized using Zeiss Axiovert 40 inverted microscope.
Figure 6
Effect of p53 knockdown on cisplatin sensitization by NSC109268. Cells were transfected with or without control non-targeting siRNA or p53 siRNA as described under Methods. Cells were then treated with or without 2 μM NSC102968 and 40 μM cisplatin. A, Western blot analysis was performed with total cell lysates as described under legend to Figure 4. B, Cells were stained with Yo-Pro-1 and PI as described under legend to Figure 5.