Figure 4. The proline-rich domain of p53 affects DNA damage-induced cell death in airway epithelial cells.

(A) H1299p53^tsArg and H1299p53^tsPro cells treated with 50 ng/ml DRB, and either 1 µM doxorubicin, 10 µM cyclohexamide, or 1 µM thapsigargin, and cell numbers quantified 48 h later. (B) p53 levels were increased in p53^WT and p53^AXXA MEFs when treated with 10 mJ UV irradiation. (C) p53^WT and p53^AXXA MEFs treated with 10 mJ UV irradiation in the presence of 50 ng/ml DRB and cell death analyzed by Annexin V and propidium iodide (PI) staining. (D) Quantification of Annexin V-positive cells in p53^WT and p53^AXXA MEFs following treatment for 8 h with 50 ng/ml DRB and either 10 mJ UV irradiation, 1 µM doxorubicin, 5% O₂ (hypoxia), 95% O₂ (hyperoxia), or 1 µM thapsigargin. (E) Western blot verifying the presence of p53 after infection of p53^WT and p53^AXXA MEFs with adenoviral vectors expressing p53^Arg or p53^Pro. (F) p53^WT and p53^AXXA MEFs were either left untreated (control) or infected with adenoviral vectors for p53^Arg or p53^Pro then treated with 1µM doxorubicin for 24 h and cell numbers quantified. Bars = group means ± standard error from the mean (n = 3 different treatments/group) ; * P<0.05; ** P<0.01.