Figure 3
Methylation of the MTA1 promoter CpG island 1 leads to inhibition of p53 binding. (a) Schematic presentation of the human MTA1 promoter encoding p53-binding sequences (p53RE) and DNA regions for ChIP and pull-down experiments. (b) Chang liver cells were transfected with empty vector (EV) or p3XFLAG7.1-HBx. DNA fragments that immunoprecipitated by anti-p53 (left) and anti-acetyl histone 3 lysine 9 (right) were amplified by PCR using primers specific for ChIP1 and ChIP2. (c) Nuclear extracts obtained from HCT116 cells were incubated with unmethylated or methylated double-stranded biotin end-labeled oligonucleotide probes. Precipitates pulled down by sterptoavidine beads were analyzed for p53 binding by western blotting. (d) WRL-68 cells were transfected with si-GFP or si-p53. After 24 h of transfection, cells were transfected with EV or p3XFLAG7.1-HBx for another 24 h. Expression of the indicated proteins was analyzed by western blotting.
