Fig. 6

Stress-induced miR-22 transcriptional expression patterns depended on the p53 activation. a Time-dependent changes of PI3K/Akt/NF-κB pathway molecules and p53 after exposure to low doses (0.5μg/ml) of CDDP; accordingly, there were no significant difference on increments of expression of miR-22 and C17orf91 quantified by qRT-PCR. b, Time-dependent changes of PI3K/Akt/NF-κB pathway molecules and p53 after exposure to higher doses (10μg/ml) of CDDP; accordingly, significant difference was observed on increments of expression of miR-22 and C17orf91 quantified by qRT-PCR, versus no treatment, *p < 0.05. c and d Ectopic overexpression of p53 in CAL-27 cells enhanced the expression of miR-22 and C17orf91 at the transcriptional level, versus control, *p < 0.05. e Chromatin immunoprecipitation assays identified p53 binding sites within the putative promoter. PCR reaction products from the miR-22 promoter group, site A and site B represent p53 immunoprecipitation, and the input represent DNA directly after lysis. In the GAPDH group, the PCR product from the RNA Polymerase antibody represents positive control, and the PCR from IgG and ddH2O (no DNA) represent the negative controls; f the activity of the putative promoter of miR-22 was higher in CAL27 cells with endogenous miR-22 overexpression. g and h, HCT116 WT and HCT116 p53^−/− cells were treated with control or CDDP (10 μg/ml). Relative fold induction of miR-22 expression and NF-kB activity were shown as mean ± s.d. *P < 0.05