Fig. 3

Effect of p53 silencing on cytotoxicity of FrA. a, b Western blotting analysis of p53 expression in RT112 cells treated with FrA for 48 h (a) or transfected with p53 siRNA versus cells transfected with scrambled siRNA (b). c Viability of transfected cells treated with FrA or Cis for 48 h. Cell viability was analyzed by flow cytometry analysis using annexin-V-FITC/PI double staining. Viable cells appearing in the lower left quadrant were quantified using the Cell Quest Pro software. d, e Effect of pifithrin-α (Pif-α)–an inhibitor of p53 activity–on the cytotoxic activity of FrA and Cis in nontransfected RT112 cells. Cells were pretreated with 40 μM of Pif-α for 30 min and then cotreated with FrA (d) or Cis (e) for 48 h. Cell viability was determined using MTT-assay