PTEN-deficient intestinal stem cells initiate intestinal polyposis

Intestinal Polyposis

Suppression of intestinal polyposis in Mdr1-deficient ApcMin/+ mice.

Aberrant transactivation of a certain set of target genes by the beta-catenin and T-cell factor/lymphoid enhancer factor complex has been considered crucial for the initiation of intestinal tumorigenesis. The human multidrug resistance (MDR)1 (ABCB1) gene contains multiple beta-catenin-T-cell factor4-binding elements in its promoter and is one of the immediate targets of the complex. In the cur...

Putative intestinal stem cells

A heterogeneous set of intestinal stem cells markers has been described in intestinal glands but the ultrastructural identity of intestinal stem cells remains unknown. By using electron microscopy, this study demonstrated the presence of cells with stem morphology in the intestinal glands of mice of different ages. These putative intestinal stem cells have large, euchromatic, irregular shaped n...

Familial intestinal polyposis.

Familial polyposis is of interest for its own sake as a sort of pathological curiosity and also in relation to the problem of cancer. The term " polyposis " is used to describe a widespread adenomatous proliferation of the intestinal mucous membrane, leading to the formation of multiple adenomata. It should not be applied to intestinal polyps of different histological structure, such as inflamm...

Gastrointestinal stem cells. II. Intestinal stem cells.

Current views of the identity, distribution, and regulation of small intestinal epithelial stem cells and their immediate progeny are discussed. Recent works implicating Wnt signaling in stem and progenitor proliferation, the involvement of Notch signaling in epithelial lineage specification, and the role of hedgehog and bone morphogenetic protein families in crypt formation are integrated. We ...