FIGURE 5.

ADR-mediated recruitment of p53 and RUNX1 onto p53 target promoters. A--C, ChIP assay. HCT116 cells were treated with 0.5 μm ADR or were left untreated. Twenty four hours after ADR treatment, cells were fixed in formaldehyde and lysed in SDS-lysis buffer, and chromatin DNA-protein complexes were immunoprecipitated (IP) with anti-p53 (A) or with anti-RUNX1 (B) antibody. The immunoprecipitated DNA was purified and subjected to RCR analysis. Alternatively, p53-deficient H1299 cells were transiently transfected with the indicated combinations of the expression plasmids. Forty eight hours after transfection, cells were fixed in formaldehyde and lysed in SDS-lysis buffer, and chromatin DNA-protein complexes were immunoprecipitated with anti-p53 or with anti-RUNX1 antibody. The immunoprecipitated DNA was purified and analyzed by PCR (C).