WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

Jurrit Zeilstra, Sander P. J. Joosten, Felix M. Wensveen, Mark C. Dessing, Denise M. Schütze, Eric Eldering, Marcel Spaargaren, Steven T. Pals

Research output: Contribution to journalArticleAcademicpeer-review

25 Citations (Scopus)

Abstract

In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or beta-catenin causes constitutively active beta-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc(Min/+) mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Box. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of beta-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which uncontrolled epithelial cell proliferation in the stem cell compartment can be counterbalanced by an increased propensity to undergo cell death. (C) 2010 Elsevier Inc. All rights reserved
Original languageEnglish
Pages (from-to)1-6
JournalBiochemical and Biophysical Research Communications
Volume406
Issue number1
DOIs
Publication statusPublished - 2011

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