Figure 4.

DNA-damaging agents increase ET-1 mRNA abundance in a p53-dependent manner. (a) The 786-O and 786-O/VHL cells were treated with increasing concentrations of CPT for 24 h and analyzed for mRNA expression of ET-1 by real-time quantitative PCR relative to GAPDH. (b) Cells as indicated were treated with 2 μM CPT (+) or vehicle DMSO (−) for 24 h and analyzed for mRNA expression of ET-1 by real-time quantitative PCR relative to GAPDH. (c) The 786-O/VHL cells were treated with vehicle DMSO, 2 μM CPT, 100 μM etoposide (ETO) or 10 μM nutlin-3a (N3) and analyzed for mRNA expression of ET-1 by real-time quantitative PCR relative to GAPDH. (d) The 786-O and RCC4 cells and their VHL-expressing counterparts were treated with vehicle control, 10 μM or 50 μM nutlin-3a (N3) for 2 or 24 h. Whole-cell lysates were assayed by western blot for phosphorylated-S15-p53, p53 and cleaved PARP proteins. Actin was used as a loading control. In the graphs, mean±S.E. of duplicate values of one representative experiment is shown. * P<0.05 as compared with control