Figure 4
Analysis of p53 inducibility of BH3-only protein expression. Constitutive protein expression and inducibility of Nbk expression as compared with the BH3-only proteins Puma and Bim was determined by Western blot analysis. Cells were stressed either by adenoviral overexpression of p53 or Nbk. Ad-LacZ served as a negative control for adenoviral gene transfer. Ad-Nbk served both as a positive control for Nbk expression and as an independent cellular stress stimulus. Expression of BimEL and BimL (but not BimS) was detected in RCC-MF but not in the other six RCC lines. Constitutive expression of Nbk was absent in all seven lines, but was inducible by p53 in RCC-MF. Puma was expressed constitutively and was inducible upon p53 overexpression. Analysis of p21CIP/WAF-1 expression served as a control for p53 function. Detection of actin was performed as a loading control
