title: Visualization of CD44 and CD133 in normal pancreas and pancreatic ductal adenocarcinomas: non-overlapping membrane expression in cell populations positive for both markers.
abstract: Tumor-initiating cells of pancreatic ductal adenocarcinoma (PDAC) have been isolated based on expression of either CD133 or CD44. The authors aimed to visualize pancreatic cells simultaneously expressing both these cell surface markers by employing the same antibodies commonly used in cell-sorting studies. Normal and diseased pancreatic tissue, including 51 PDAC cases, were analyzed. CD44 and CD133 expression was determined by immunohistochemical double staining on formalin-fixed material and subcellular protein distribution evaluated by immunofluorescence/confocal microscopy. In the normal pancreas, CD44 and CD133 were coexpressed in the centroacinar regions but in non-overlapping subcellular compartments. As expected, CD44 was found mainly basolaterally, whereas CD133 was present on the apical/endoluminal membrane. This was also the case in chronically inflamed/atrophic pancreatic tissue and in PDAC. In some malignant ducts, CD44 was found at the apical cell membrane adjacent to but never overlapping with CD133 expression. CD44 level was significantly associated with the patient's lymph node status. In conclusion, a CD44+/CD133+ cell population does exist in the normal and neoplastic pancreas. The preferentially centroacinar localization of the doubly positive cells in the normal parenchyma suggests that this population could be of particular interest in attempts to identify tumor-initiating cells in PDAC.
authors.affiliation: Section for Pathology, Gade Institute, University of Bergen, Bergen, Norway.
authors.forename: Heike
authors.initials: H
authors.lastname: Immervoll
authors.forename: Dag
authors.initials: D
authors.lastname: Hoem
authors.forename: Ole Johnny
authors.initials: OJ
authors.lastname: Steffensen
authors.forename: Hrvoje
authors.initials: H
authors.lastname: Miletic
authors.forename: Anders
authors.initials: A
authors.lastname: Molven
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D016022:Case-Control Studies; D002462:Cell Membrane / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis*; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis*; D053208:Kaplan-Meier Estimate; D010179:Pancreas / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D010455:Peptides
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; C497483:CD44 protein, human; D006023:Glycoproteins; D018960:Hyaluronan Receptors; C000606023:PROM1 protein, human; D010455:Peptides