Searching across hundreds of databases
The p53 tumor suppressor gene has a common polymorphism at codon 72 that alters its function. We previously reported that the proline 72 polymorphic variant of p53 (P72) demonstrates increased ability to transactivate a subset of genes, relative to arginine 72 (R72); one of these genes is macrophage colony stimulating factor (CSF1). At present, the mechanism(s) underlying the increased transcriptional activity of P72 toward genes like CSF1 have not been completely elucidated. Additionally, the consequences of increased transcription of genes like CSF1 by the P72 variant to the downstream p53 pathway are unknown. In this report, we address these issues. We show that the CSF1 gene contains a conserved binding site for p53, and interestingly that the P72 variant shows increased ability to bind to this site. Moreover, we show that increased CSF1/CSF1R signaling in P72 cells feeds back on the p53 pathway to enhance p53 phosphorylation, levels, and transactivation of target genes, particularly the cyclin-dependent kinase inhibitor p21 (CDKN1A). This leads to an increase in p53-mediated growth arrest, along with a concomitant decrease in apoptosis. Notably, the CSF1/CSF1R signaling axis is overexpressed in several epithelial cancers, and there is clinical evidence that this pathway plays a role in radio-resistance of some cancers. We show that cells expressing CSF1 and CSF1R are indeed radio-resistant, and further, that this effect requires p53. These combined data are the first to implicate the CSF1/CSF1R pathway in the decision between p53-mediated growth arrest and apoptosis. They are also the first to highlight a cytokine as influential in cell fate determined by p53 in epithelial cells. Finally, these data may explain the association of the P72 variant and the CSF1/CSF1R pathway with increased senescence and radio-resistance in some epithelial tumor types.
Pubmed ID: 24019961 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
A Kernel Density Estimator-based package for analysis of massively parallel sequencing data from chromatin immunoprecipitation (ChIP-seq) experiments.
View all literature mentionsCell line HEK293-FT is a Transformed cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line p53HCT116 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line U2OS is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line Hep 3B2.1-7 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line NCI-H1299 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsMus musculus with name C57BL/6J from IMSR.
View all literature mentionsCell line Hep-G2 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsThe SciCrunch Infrastructure was developed as a cooperative data platform to be used by diverse communities in making data more FAIR.
scicrunch.org
