Fig. 4

S9 stabilizes p53 and increases p53 transcriptional activity. A U2OS and HCT116 cells were treated with described concentration of S9 for 24 h. MDM2, p53 and p21 protein levels were detected by western blot analysis. B U2OS and HCT116 cells were treated with 50 μM of S9 for different time course. MDM2, p53 and p21 protein levels were detected by western blot analysis. C U2OS and HCT116 cells were treated with or without 25 μM of S9 for 24 h followed with cycloheximide (CHX, 50 μg/ml), and harvested at the indicated time points. p53 and actin levels were detected by western blot analysis. p53 expression normalized with actin was quantified using Image J software. D U2OS cells were treated with described concentration of S9 for 24 h. mRNA levels of MDM2, p21, Puma and Bax were analyzed by RT-PCR. Fold expression changes are relative to the control and correspond to mean ± SD of three independent experiments