p53 induces CGB7 expression in different cell systems. (A–C) p53 protein was detected by immunoblot, β-actin serving as loading control. (D–F) CGB protein levels were measured by immunoassay. (G–I) mRNA levels of CGB isoforms were determined by real-time RT-PCR. (A, D and G) Human foreskin fibroblasts (HFF) were treated with doxorubicin (doxo) for 48 h. (B, E and H) In the human colorectal adenocarcinoma cell line DLD-1 carrying tet-off inducible p53 wild-type (p53wt) or R175H mutant (p53mut) transgenes in a functionally p53-negative background the expression of transgenes was induced for 9 h. (C, F and I) HCT116 cells with wild-type p53 (HCT116 p53+/+) or with targeted deletions in both p53 alleles (HCT116 p53−/−) were treated with doxorubicin for 48 h. (D–I) Mean ± SD, n = 3, *p < 0.05, **p < 0.01.