CRIF1 enhances p53 activity via the chromatin remodeler SNF5 in the HCT116 colon cancer cell lines

CR6-interacting factor 1 (CRIF1) is ubiquitously expressed in human tissues. CRIF1 was first identified as a Gadd45γ (also known as CR6)-interacting protein, and it was also identified in a human colon cancer cell line stably transformed with p53. These results suggested that CRIF1 functions in the nucleus with p53 and Gadd45 family proteins in the suppression of cell growth and tumor development. Here, we found that CRIF1 could be recruited to a specific region in the promoter of the p53 gene, eliciting an increase in the mRNA and protein levels of p53 as well as p53 functional target genes. These functions required CRIF1 to interact with SNF5. CRIF1 was further recruited to the upstream promoter region of the p53 gene to suppress cell cycle progression in HCT116 cells. To our knowledge, this is the first evidence indicating that SNF5 is indispensable for CRIF1-enhanced p53 activity and its function in the suppression of cell cycle arrest in human cancer cells.