Cell Context Dependent p53 Genome-Wide Binding Patterns and Enrichment at Repeats

ABSTRACT: We mapped the genomic binding sites of the tumor suppressor protein p53 in the human colorectal cancer cell line HCT116 and report here that the binding patterns of endogenous wild type p53 differed significantly between the genomes of the cancer cell line HCT116 and the normal human IMR90 fibroblasts (GSE31558) under the same experimental conditions (6 hr treatment with 5-fluorouracil). p53 binding differences affect promoter regions, CpG islands and major families of human repeat elements such as LTR, LINE and SINE. While p53 genomic binding sites residing in repeats have been reported before, we show here that the fraction of the p53 genomic binding sites residing in different repeat families differs between the normal and cancer human cell lines. We confirm that the p53 genomic binding sites in HCT116 cells are excluded from CpG islands, an observation we made previously based on analysis of data reported by others. While the p53 ability to elicit stress-specific and cell-type-specific responses is well documented, how this specificity is established, at the level of binding to the genome and/or during post-binding events, represents an open question. Our data indicate that p53 binding to the human genome is cell line-specific and highly selective. The differences in the p53 genome-wide binding patterns between the cancer cell line HCT116 and the normal cell line IMR90, namely exclusion from CpG islands and enrichment at repeats in HCT116, likely reflect cancer-associated epigenetic changes in the chromatin. Identification of genomic p53 binding sites in HCT116 cells by ChIP-seq.

ORGANISM(S): Homo sapiens

SUBMITTER: Krassimira Botcheva 

PROVIDER: E-GEOD-58714 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress