p27kip1 Regulates cdk2 Activity in the Proliferating Zone of the Mouse Intestinal Epithelium: Potential Role in Neoplasia

Abstract

Background & Aims: Reduced p27kip1 expression is a marker of poor prognosis in colorectal neoplasia, and inactivation of p27 in mice (p27Δ51/Δ51) causes increased intestinal epithelial cell proliferation and small and large intestinal neoplasia in a diet-dependent manner. Here, we addressed the role of p27 in untransformed intestinal epithelial cells in vivo and the consequence of its targeted inactivation. Methods: A sequential fractionation procedure was used to isolate murine intestinal epithelial cells relative to their position along the crypt-villus axis, and the levels of cyclins, cyclin-dependent kinases (cdks), and cdk inhibitors and of the complexes formed among them was determined..