TRRAP silencing attenuates stabilization and activity of wtp53 upon genotoxic stress. (A) Seraphina wtp53 BL cells were transduced with shRNAs against TRRAP, p53, or a nontargeting control (NT). 5 days after transduction, cells were treated with DMSO (0.1%) or etoposide (25 µM) for 8 hours before they were subjected to p53 flow cytometry. Values denote p53 MFI normalized to cells transduced with the NT. Hollow histograms indicate isotype control stainings, and filled histograms indicate samples stained with anti-p53. (B) Protein level of p53, p21, and PARP in Seraphina wtp53 BL cells transduced with shRNAs against TRRAP, p53, or a nontargeting control (NT). Cells were selected with puromycin for 72 hours. 6 days after transduction, cells were treated with DMSO (0.1%) or etoposide (25 µM) and harvested at the indicated time points. Expression was determined by western blot and normalized to GAPDH and to cells transduced with the NT. Arrows indicate the specific bands for p53.