beta-catenin


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beta-catenin

A cell–cell adhesion protein that binds to the cytoplasmic domain of E-cadherin. The beta-catenin-cadherin complex recruits alpha-catenin, which in turn binds actin of the cytoskeleton, together forming intercellular adherens junction. Beta-catenin also acts as a component of the Wnt signal transduction pathway, which regulates cell proliferation and differentiation. Tissue concentrations of free beta-catenin are controlled by a protein complex (adenomatous polyposis coli protein and glycogen synthetase kinase3a) which facilitates its breakdown. Wnt inactivates glycogen synthetase kinase3b, allowing beta-catenin to accumulate in cytoplasm and in the nucleus, where it activates the TCF/LEF transcription factors, which in turn act on c-myc, tcf-1 and cyclin D1.

Normal expression
Normal cells show membrane staining for beta-catenin. Beta-catenin expression is regulated by the adenomatous polyposis coli (APC) gene.
 
Abnormal expression
Cytoplasmic and/or nuclear staining is abnormal. Mutant CTNNB1 can lead to stabilisation of beta-catenin in the cytoplasm and translocation to the nucleus; disregulation of beta-catenin occurs in Gardner syndrome, leading to familial adenomatous polyposis and fibromatosis. Beta-catenin expression is increased in aggressive fibromatosis, synovial sarcoma, osteosarcoma, liposarcoma and malignant fibrous histiocytoma. High nuclear expression is seen in some mesenchymal tumours; cytoplasmic staining is seen in many. In contrast, cytoplasmic accumulation of beta-catenin is a generally good prognostic marker in upper and lower GI adenocarcinomas.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
References in periodicals archive ?
The relative mRNA expression levels of genes (DKK-1, beta-catenin, c-myc, cyclin D1, and survivin) were normalized to GAPDH, calculated by using the [2.sup.-[DELTA][DELTA]Ct] method.
Kaykas, "WNT and beta-catenin signalling: diseases and therapies," Nature Reviews.
Biotin-rich, optically clear nuclei express estrogen receptor-beta: tumors with morules may develop under the influence of estrogen and aberrant beta-catenin expression.
Thus, beta-catenin, GSK-3beta, and the ratio of phosphorylated/dephosphorylated GSK-3beta were detected to determine whether inhibiting the Wnt/beta-catenin signaling pathway is the key to induce MSCs differentiation into cardiomyocytes.
The microphthalmia-associated transcription factor Mitf interacts with beta-catenin to determine target gene expression.
Nuclear beta-catenin expression distinguishes deep fibromatosis from other benign and malignant fibroblastic and myofibroblastic lesions.
Expression of epithelial-cadherin, alpha-catenin and beta-catenin during human intrahepatic bile duct development: a possible role in bile duct morphogenesis.
Our data suggest that the broad spectrum of pharmacological action of Uncaria tomentosa involves inhibition of the Wnt-signaling pathway, downstream of beta-Catenin activity.
Beta-catenin, an inducer of uncontrolled cell proliferation and migration in malignancies, is localized in the cytoplasm of vascular endothelium during neovascularization after myocardial infarction.
Frecuent mutations of beta-catenin in mouse colon tumors induces by azoxymethane.
Biphenotypic sinonasal sarcoma: an expanded immunoprofile including consistent nuclear beta-catenin positivity and absence of SOX10 expression.