July 2009

Document Type


Degree Name



Dept. of Molecular and Medical Genetics


Oregon Health & Science University


The Wnt signaling pathway is an essential regulator of the intestinal epithelium, during development and throughout adulthood. Inappropriate activation of this pathway leads to over-proliferation of the epithelium and intestinal cancer, whereas inhibition causes a loss of stem cells and collapse of the intestinal epithelium. To date, there are 19 Wnt ligands that have been identified in both mice and humans, several of which are expressed in the intestine. However, not all Wnt ligands serve to activate the canonical pathway that signals through β-catenin, and the functional role of the various ligands in the intestinal epithelium has not been conclusively determined. In the mature intestine, proliferation is confined to the relatively quiescent stem cells and the rapidly cycling transient-amplifying cells within the intestinal crypts. Although the Wnt signal has previously been reported to regulate all proliferating intestinal cells, this has not been definitively demonstrated. A preci




School of Medicine



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.