Fig. 5: p53 downregulates BRCA1 and BRCA2 expression indirectly via inducing expression of p21/CDKN1A.
From: BRCA1 and BRCA2 gene expression: p53- and cell cycle-dependent repression requires RB and DREAM
A p53-positive wild-type (p53+/+) or p21-negative (p21-/-) HCT116 cells were treated for 48 h with nutlin-3a, or DMSO as control. Expression levels of mRNAs were determined by qPCR (Mean ± SD, n = 3, two-way ANOVA; ***p ≤ 0.001). B HCT116 p21-/- cells were transfected with wild-type (wt) BRCA1 or BRCA2 promoter reporter constructs together with expression plasmids for wild-type or mutant variants of p53 (p53 wt; p53 mut) or p21 (p21 wt; p21 mut). 24 h after transfection, promoter reporter activities were analyzed by luciferase assays with relative luciferase activity calculated as the ratio of firefly luciferase activity from the promoter reporter constructs to Renilla luciferase activity from a cotransfected control plasmid lacking a promoter (Mean ± SD, n = 2 to 4; two-way ANOVA; *p ≤ 0.05; ***p ≤ 0.001).
