Gastrointestinal tumors beta-catenin

Eew studies have been done on the molecular features of gastrointestinal endocrine tumors. Allelic loss of llq has been detected in GI endocrine tumors associated with MENl, and LOH of 1 Iq is also present in a subset of sporadic GI endocrine tumors. Mutations of the MENl gene are present in approximately 30% of sporadic gastrinomas and in occasional midgut and hindgut endocrine tumors. In contrast to pancreatic endocrine tumors, the CpG island methylator phenotype is frequent in GI endocrine tumors. Beta-catenin exon 3 mutations are relatively common (38%) in these tumors, and up to 80% of the tumors show nuclear and cytoplasmic localization of the corresponding protein. Other studies, however, reported absence of exon 3 mutations, but nuclear f5-catenin was found in 30% of cases. In contrast, extra-GI endocrine tumors were negative for nuclear f5-catenin. 

Fujimori M, Ikeda S, Shimizu Y, et al. Accumulation of beta-catenin gene in gastrointestinal carcinoid tumor. Cancer Res. 2001 61 6656-6659. 

Su MC, Wang CC, Chen CC, et al. Nuclear translocation of beta-catenin and APC mutation in gastrointestinal carcinoid tumor. Ann Surg Oncol. 2006 13 1604-1609. 

Montgomery E, Torbenson MS, Kaushal M, et al. Beta-catenin immunohistochemistry separates mesenteric fibromatosis from gastrointestinal stromal tumor and sclerosing mesenteritis. Am J Surg Pathol. 2002 26 1296-1301. 

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