title: Mesothelin is overexpressed in pancreaticobiliary adenocarcinomas but not in normal pancreas and chronic pancreatitis.
abstract: Mesothelin, a cell surface glycoprotein present on normal mesothelial cells, has been reported to be expressed in pancreatic adenocarcinomas. We conducted this study to fully characterize mesothelin expression in surgically resected, formalin-fixed, paraffin-embedded tissue specimens of 18 pancreatic adenocarcinomas, 9 adenocarcinomas of the ampulla of Vater, 12 adenocarcinomas of the common bile duct, and 17 cases of chronic pancreatitis. Mesothelin immunostaining was performed using the antimesothelin monoclonal antibody 5B2. All 18 cases (100%) of pancreatic adenocarcinomas showed mesothelin expression, as did 8 (89%) of 9 cases of ampullar adenocarcinoma and all 12 cases (100%) of common bile duct adenocarcinoma. In all cases of pancreaticobiliary adenocarcinoma, the adjacent normal pancreas did not stain for mesothelin. Of 17 specimens of chronic pancreatitis, 16 were negative for mesothelin expression, and 1 case showed weak mesothelin staining of fewer than 5% of normal pancreatic ducts. Our results demonstrated mesothelin expression in the majority of pancreaticobiliary adenocarcinomas and no expression in normal pancreatic tissues and in chronic pancreatitis.
authors.affiliation: Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264, USA.
authors.forename: Raffit
authors.initials: R
authors.lastname: Hassan
authors.forename: Zoltan G
authors.initials: ZG
authors.lastname: Laszik
authors.forename: Megan
authors.initials: M
authors.lastname: Lerner
authors.forename: Mark
authors.initials: M
authors.lastname: Raffeld
authors.forename: Russell
authors.initials: R
authors.lastname: Postier
authors.forename: Daniel
authors.initials: D
authors.lastname: Brackett
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis*; D003135:Common Bile Duct / Q000378:metabolism / Q000473:pathology; D058851:GPI-Linked Proteins; D006801:Humans; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D000090204:Mesothelin; D010179:Pancreas / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D050500:Pancreatitis, Chronic / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D000090204:Mesothelin