Figure 5.

NB124 promotes p53-dependent apoptosis. (A) Induction of PARP-1 cleavage: Western blot analysis of poly (ADP-ribose) polymerase (PARP-1) cleavage in cell lysates obtained from H1299-p53R213X cells treated with NB124 (0.4 mg/ml) or gentamicin (0.8 mg/ml) for 30 or 50 hours. NT: non treated. Visible bands correspond to the full-length PARP-1 (116 kDa) and the larger fragment of the cleaved protein (89 kDa), and the β-actin used as a loading control. Percentage of the cleaved form is calculated as the ratio cleaved/ (cleaved + full length). (B) AnnexinV-PE staining: H1299-p53R213X cells were transiently transfected with a p53-targeting siRNA (p53-siRNA) or a non-targeted siRNA (NT-siRNA) or were left untransfected (−). Cells were then left untreated or treated with NB 124 (0.4 mg/ml) or gentamicin (1.2 mg/mL) for 50 hours. Percentages indicate the proportion of Annexin-PE-positive cells detected on flow cytometry, corresponding to cells undergoing apoptosis, with exposed PS (overall apoptosis).