beta-catenin has a role in cell adhesion and Wnt signaling. It is mutated or otherwise dysregulated in a variety of human cancers. In this study we assess beta-catenin alteration in 145 thyroid tumors samples from 127 patients. beta-catenin was localized using immunofluorescence and mutational analysis was performed by single-strand conformational polymorphism. Membrane beta-catenin expression was decreased in eight of 12 (66%) adenomas and in all 115 carcinomas (P: < 0.0001). Among carcinomas, reduced membrane beta-catenin was associated with progressive loss of tumor differentiation (P: < 0.0001). CTNNB1 exon 3 mutations and nuclear beta-catenin localization were restricted to poorly differentiated [7 of 28 (25%) and 6 of 28 cases (21.4%), respectively] or undifferentiated carcinomas [19 of 29 (65.5%) and 14 of 29 (48.3%) cases, respectively]. Poorly differentiated tumors always featured mutations involving Ser and Thr residues and were characterized by Thr to Ile amino acid substitutions (P: = 0.0283). The association between CTNNB1 exon 3 mutations and aberrant nuclear immunoreactivity (P: = 0.0020) is consistent with Wnt activation because of stabilizing beta-catenin mutations. Low membrane beta-catenin expression as well as its nuclear localization or CTNNB1 exon 3 mutations are significantly associated with poor prognosis, independent of conventional prognostic indicators for thyroid cancer but not of tumor differentiation. Analysis of beta-catenin dysregulation may be useful to objectively subtype thyroid neoplasms and more accurately predict outcomes.
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http://dx.doi.org/10.1016/s0002-9440(10)64045-x | DOI Listing |
J Clin Pathol
December 2024
Institute of Tissue Medicine and Pathology, University of Bern, Bern, Switzerland
Aims: Mutations affecting exon 3 of the β-catenin () gene result in constitutive activation of WNT signalling and are a diagnostic hallmark of several tumour entities including desmoid-type fibromatosis. They also define clinically relevant tumour subtypes within certain entities, such as endometrioid carcinoma. In diagnostics, β-catenin immunohistochemistry is widely used as a surrogate for mutations.
View Article and Find Full Text PDFbioRxiv
November 2024
Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, USA.
Missense mutations in exon 3 of , the gene encoding β-catenin, are associated with poor outcomes in endometrial carcinomas (EC). Clinically, mutation status has been difficult to use as a predictive biomarker as β-catenin oncogenic activity is modified by other factors, and these determinants are unknown. Here we reveal that CD73 restrains the oncogenic activity of exon 3 β-catenin mutants, and its loss associates with recurrence.
View Article and Find Full Text PDFHistopathology
November 2024
Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
Aims: The frequency of CTNNB1 mutation, one of the most frequent genetic events in hepatocellular carcinoma (HCC), is lower in Asian countries and in hepatitis B virus (HBV)-related HCCs. In this study, we evaluated the prevalence and types of CTNNB1-mutation in HBV-related HCC and correlated the molecular status with the histomorphological and immunohistochemical features.
Methods And Results: A total of 108 consecutive cases of treatment-naïve, surgically resected HBV-related HCCs were selected.
Am J Clin Pathol
October 2024
Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, US.
Ann Surg Oncol
December 2024
Sarcoma Service, Department of Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
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