Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P16104 (H2AX)
 3,930 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The patched (Ptc1) protein is a negative regulator of sonic hedgehog signaling, a genetic pathway whose perturbation causes developmental defects and predisposition to specific malignant tumors. Humans and mice with mutated Ptc1 are prone to medulloblastoma and basal cell carcinoma (BCC), both tumors showing dependence on radiation damage for rapid onset and high penetrance. Poly(ADP-ribose) polymerase (PARP-1) is a nuclear enzyme that plays a multifunctional role in DNA damage signaling and repair. In healthy and fertile PARP-1-null mice, radiation exposure reveals an extreme sensitivity and a high genomic instability. To test for interactions between PARP-1 and sonic hedgehog signaling, PARP-1-null mice were crossed to Ptc1 heterozygous mice. PARP-1 deletion further accelerated medulloblastoma development in irradiated Ptc1(+/-) mice, showing that PARP-1 inactivation sensitizes cerebellar cells to radiation tumorigenic effects. In addition to increased formation and slowed down kinetics of disappearance of gamma-H2AX foci, we observed increased apoptosis in PARP-1-deficient granule cell progenitors after irradiation. Double-mutant mice were also strikingly more susceptible to BCC, with >50% of animals developing multiple, large, infiltrative tumors within 30 weeks of age. The results provide genetic evidence that PARP-1 function suppresses sonic hedgehog pathway-associated tumors arising in response to environmental stress.
 ...
PMID:PARP-1 cooperates with Ptc1 to suppress medulloblastoma and basal cell carcinoma. 1866 May 45

WW domain containing oxidoreductase, designated WWOX, FOR or WOX1, is a known pro-apoptotic factor when ectopically expressed in various types of cancer cells, including glioblastoma multiforme (GBM). The activation of sonic hedgehog (Shh) signaling, especially paracrine Shh secretion in response to radiation, is associated with impairing the effective irradiation of cancer cells. Here, we examined the role of Shh signaling and WOX1 overexpression in the radiosensitivity of human GBM cells. Our results showed that ionizing irradiation (IR) increased the cytoplasmic Shh and nuclear Gli-1 content in GBM U373MG and U87MG cells. GBM cells with exogenous Shh treatment exhibited similar results. Pretreatment with Shh peptides protected U373MG and U87MG cells against IR in a dose-dependent manner. Cyclopamine, a Hedgehog/Smoothened (SMO) inhibitor, reversed the protective effect of Shh in U87MG cells. Cyclopamine increased Shh plus IR-induced H2AX, a marker of DNA double-strand breaks, in these cells. To verify the role of Shh signaling in the radiosensitivity of GBM cells, we tested the effect of the Gli family zinc finger 1 (Gli-1) inhibitor zerumbone and found that it could sensitize GBM cells to IR. We next examined the role of WOX1 in radiosensitivity. Overexpression of WOX1 enhanced the radiosensitivity of U87MG (possessing wild type p53 or WTp53) but not U373MG (harboring mutant p53 or MTp53) cells. Pretreatment with Shh peptides protected both WOX1-overexpressed U373MG and U87MG cells against IR and increased the cytoplasmic Shh and nuclear Gli-1 content. Zerumbone enhanced the radiosensitivity of WOX1-overexpressed U373MG and U87MG cells. In conclusion, overexpression of WOX1 preferentially sensitized human GBM cells possessing wild type p53 to radiation therapy. Blocking of Shh signaling may enhance radiosensitivity independently of the expression of p53 and WOX1. The crosstalk between Shh signaling and WOX1 expression in human glioblastoma warrants further investigation.
 ...
PMID:Modulation of Sonic hedgehog signaling and WW domain containing oxidoreductase WOX1 expression enhances radiosensitivity of human glioblastoma cells. 2559 87