p53 regulates miR-30a-5p and miR-30a-3p expression. a Ectopic p53 expression in MDA157 results in an augment of mature miR-30a-5p and miR-30a-3p levels. The immunoblot on the right shows p53 expression in MDA157 engineered cells. GAPDH was used as a loading control. b p53 silencing in HCT116 results in a decrement of both miR-30a-5p and miR-30a-3p. The extent of p53 silencing is shown in the right panel. c Ectopic p53 induces an increase of pri-miR-30a levels in MDA157. d Decrease of pri-miR-30a levels in p53-depleted HCT116 and MCF7 cells. a–d Gray columns represent p53-modulated samples; black columns represent control cells. e p53 regulates the MIR30A promoter. Silencing of p53 results in a decrement of the MIR30A promoter activity (30wt). The mutagenesis of the two p53 binding sites, singularly (30mut1, 30mut2) or in combination (30mut1/2), abrogates this effect. Results represent the mean value of three independent experiments ± SD. f p53 binds the miR-30a promoter. Chromatin immunoprecipitation was performed with the DO-1 anti-p53 monoclonal antibody on HCT116 genomic DNA. Isotype-matched pre-immune mouse IgG was used as a negative control. The immunoprecipitated chromatin was assayed for the enrichment of the target MIR30A promoter (miR30-1 and 2, the regions encompassing the two p53BS) by qPCR. The p53 binding region of the p21 promoter and an irrelevant genomic region (CTR neg)  were used as positive and negative control, respectively. Data are reported as fold enrichment over control samples (immunoprecipitation with pre-immune IgG) p values were calculated by two-tailed t-test; *p < 0.05, **p < 0.01.