Nuclear translocation of β-catenin protein but absence of β-catenin and APC mutation in gastrointestinal carcinoid tumor
Journal
Annals of Surgical Oncology
Journal Volume
13
Journal Issue
12
Pages
1604-1609
Date Issued
2006
Author(s)
Abstract
Background: Carcinoid tumors are a group of heterogeneous tumors with neuroendocrine differentiation and are mainly located in the gastrointestinal tract. A high frequency of cytoplasmic accumulation and/or nuclear translocation of β-catenin with frequent mutations of exon 3 of β-catenin gene in gastrointestinal carcinoid tumor has been previously described, but the role of Wnt/β-catenin/APC pathway in the genesis of carcinoid tumor remains largely unknown. Methods: To further characterize the role of Wnt/β-catenin/APC pathway, we investigated 91 gastrointestinal carcinoid tumors and, for comparison, 26 extragastrointestinal carcinoid tumors by immunohistochemical detection of β-catenin protein and direct sequencing of exon 3 of the β-catenin gene and exon 15 of the APC gene. Results: Cytoplasmic accumulation and/or nuclear translocation of β-catenin were found in 27 gastrointestinal carcinoid tumors (29.7%) but not in any extragastrointestinal carcinoid tumors. Interestingly, neither β-catenin nor APC gene mutation was detected in all of the cases with nuclear expression of β-catenin. Conclusions: Our results indicate that the role β-catenin plays in the genesis of gastrointestinal and extragastrointestinal carcinoid tumors is different. Nuclear expression of β-catenin does not occur in extragastrointestinal carcinoid tumors, and mutation of exon 3 of β-catenin gene and exon 15 of APC gene does not contribute to the activation of Wnt/β-catenin/APC pathway in gastrointestinal carcinoid tumors. © 2006 Society of Surgical Oncology.
SDGs
Type
journal article