6533b823fe1ef96bd127ee29
RESEARCH PRODUCT
Role of Gadd45a in Wip1-dependent regulation of intestinal tumorigenesis.
Yunhua ZhuDmitry V. BulavinNoboru MotoyamaOleg N. DemidovAnastasia R. GoloudinaCalvina Keksubject
Genes APCDNA RepairDNA repairDNA damageApoptosisCell Cycle ProteinsBiologyProtein Serine-Threonine KinasesReceptors G-Protein-CoupledMicePhosphoprotein PhosphatasesGene silencingAnimalsMolecular BiologyCheckpoint Kinase 2Cyclin-Dependent Kinase Inhibitor p16beta CateninMice KnockoutOriginal PaperKinaseIntestinal PolyposisStem CellsJNK Mitogen-Activated Protein KinasesNuclear ProteinsCell BiologyCell biologyProtein Phosphatase 2CCheckpoint Kinase 2Cell Transformation NeoplasticCancer researchSignal transductionStem cellTumor Suppressor Protein p53GADD45ASignal Transductiondescription
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 β-catenin signaling pathway. We propose that silencing of Gadd45a is sufficient to override p53 activation in the presence of active β-catenin under conditions of an enhanced DNA damage response.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-05-05 | Cell death and differentiation |