A Transition Zone Showing Highly Discontinuous or Alternating Levels of Stem Cell and Proliferation Markers Characterizes the Development of PTEN-Haploinsufficient Colorectal Cancer
Fig 1
An alternating pattern of Ki-67 and PTEN at the adenoma (Ad)-adenocarcinoma (ACA) transition.
(A) Ki-67 immunohistochemical staining of a primary colon cancer section shows proliferating cells restricted to the crypts in normal/hyperplastic epithelium (left); strecthes of alternating Ki-67+ proliferating and Ki-67- quiescent cells in the adenomatous region adjacent to the first areas of invasive tumor (middle); and uniform proliferation in the invasive carcinoma (right). (B) PTEN immunostaining from the same tumor shows uniform PTEN expression in the normal/hyperplastic epithelium (left), and in most of the adenomatous epithelium and invasive tumor (right). An area within the Ad-ACA transitional zone shows on-off alternating PTEN expression overlapping with the on/off Ki-67 expression.