FIGURE 5.

Unlike prolonged ΔNp53 overexpression, transient silencing of p53 in p53-expressing cells cannot induce p73-mediated apoptosis following DNA damage. a and b, p53 siRNA-transfected (a) and ΔNp53 overexpressed p53-expressing HL-60 cells (b) were challenged with 25 μm curcumin for different time periods, and expression levels of p53, MDM2, p73, Chk-1, Chk-2, ΔNp73, and Bax were analyzed by Western blotting. c, untransfected, p53 siRNA-transfected, and ΔNp53 overexpressed ectopically p53-expressing HL-60 cells were further transfected with control/p73 siRNA and then incubated with or without curcumin for 24 h, and the percent cell death was analyzed by Annexin-V-/7AAD positivity. α-Actin was used as internal loading control. Values are mean ± S.E. (error bars) of five independent experiments in each case or representative of a typical experiment.