CD133 expression is not restricted to stem cells, and both CD133⁺ and CD133^– metastatic colon cancer cells initiate tumors
J. Clin. Invest. Sergey V. Shmelkov, et al. 118:2111 doi:10.1172/JCI34401 [Go to this article.]

Figure 2
CD133 expression identifies differentiated luminal epithelium in organs with hollow cavities. (A–D) CD133 expression in bile ducts of murine liver. X-gal staining (which reflects β-galactosidase expression) of CD133^lacZ/+ mouse liver (A) and immunohistochemistry of wild-type mouse liver with anti-CD133 antibody (B) localize CD133 expression to a columnar cells within the hepatic triad morphologically defined as a bile duct (BD). Costaining with X-gal and anti-CD31 antibody (C) and coimmunofluorescence with anti-CD133 (red) and anti-CD31 antibodies (green) (D) demonstrate that CD133 is not expressed on the vessels of hepatic triads. Original magnification, ×200 (A, inset); ×400 (B and C, insets). (E–H) CD133 expression in pancreatic ducts. X-gal staining of CD133^lacZ/+ mouse pancreas (E) and immunohistochemistry of wild-type mouse pancreas with anti-CD133 antibody (F) localize CD133 expression to a ductal epithelium. Costaining with X-gal and anti-CD31 antibody (G) and coimmunofluorescence with anti-CD133 (red) and anti-CD31 antibodies (green) (H) demonstrate that CD133 is not expressed on pancreatic vessels. (I–L) CD133 expression in bronchus. X-gal staining of CD133^lacZ/+ mouse lung (I) and immunohistochemistry of wild-type mouse lung with anti-CD133 antibody (J) localize CD133 expression ubiquitously to all of the ciliated bronchial epithelium. Costaining with X-gal and anti-CD31 antibody (K) and coimmunofluorescence with anti-CD133 (red) and anti-CD31 antibodies (green) (L) demonstrate that CD133 is not expressed on the mature vessels in lungs. BRN, bronchus; BV, blood vessel; CV, central vein; PD, pancreatic duct; PV, portal vein. Scale bar: 50 μm.