First Author | Demidov ON | Year | 2012 |
Journal | Cell Death Differ | Volume | 19 |
Issue | 11 | Pages | 1761-8 |
PubMed ID | 22555459 | Mgi Jnum | J:204789 |
Mgi Id | MGI:5543355 | Doi | 10.1038/cdd.2012.57 |
Citation | Demidov ON, et al. (2012) Role of Gadd45a in Wip1-dependent regulation of intestinal tumorigenesis. Cell Death Differ 19(11):1761-8 |
abstractText | Conversion of intestinal stem cells into tumor-initiating cells is an early step in Apc(Min)-induced polyposis. Wild-type p53-induced phosphatase 1 (Wip1)-dependent activation of a DNA damage response and p53 has a permanent role in suppression of stem cell conversion, and deletion of Wip1 lowers the tumor burden in Apc(Min) mice. Here we show that cyclin-dependent kinase inhibitor 2a, checkpoint kinase 2, and growth arrest and DNA damage gene 45a (Gadd45a) exert critical functions in the tumor-resistant phenotype of Wip1-deficient mice. We further identified Gadd45a as a haploinsufficient gene in the regulation of Wip1-dependent tumor resistance in mice. Gadd45a appears to function through its ability to activate the Jnk-dependent signaling pathway that in turn is a necessary mediator of the proapoptotic functions of p53 that respond to activation of the beta-catenin signaling pathway. We propose that silencing of Gadd45a is sufficient to override p53 activation in the presence of active beta-catenin under conditions of an enhanced DNA damage response. |