Fig. 5: p53 is important for ECRG2 induction in response to DNA damage.

a ECRG2 promoter is activated by DNA damage in a p53-depenent manner. p53^+/+ or p53^−/− RKO cells were transiently transfected with ECRG2-full-luc reporter plasmid for 24 hours. The cells were treated with 30 μM etoposide or DMSO for additional 24 h, and the promoter activity was measured by luciferase assay. The values are presented as mean ± SEM (n = 3). b, c Induction of ECRG2 mRNA and protein in response to DNA damage is p53-dependent. p53^+/+ or p53^−/− RKO cells were treated with 30 μM etoposide or DMSO for 24 hours. The mRNA levels were analyzed by qRT-PCR (b), and the protein levels were analyzed by Western blotting (c). Results in (b) represent mean ± SEM (n = 3). Numbers underneath the blot in (c) indicate fold induction in ECRG2 protein levels. Ponceau S staining was used to corroborate total protein loading indicated by vinculin. *p < 0.05, **p < 0.01.