title: Secretion of N-ERC/mesothelin and expression of C-ERC/mesothelin in human pancreatic ductal carcinoma.
abstract: ERC/mesothelin gene (MSLN) encodes a precursor protein, which is cleaved by proteases to generate N-ERC/mesothelin and C-ERC/mesothelin. N-ERC/mesothelin is a soluble protein, also known as megakaryocyte-potentiating factor, which is released into extracellular space. N-ERC/mesothelin is known to be a serum marker of mesothelioma. We have previously developed an enzyme-linked immunosorbent assay system for N-ERC/mesothelin, which can detect mesothelioma. C-ERC/mesothelin is expressed in normal mesothelial cell, pancreatic cancers, ovarian cancers, mesotheliomas and some other cancers. Pancreatic ductal carcinoma remains a fatal disease because its diagnosis often occurs very late. In this study, we examined ERC/mesothelin expression in human pancreatic cancer cell lines (MIA-PaCa2, PK-1, KP-3, TCC-PAN2, PK-59 and PK-45H) by reverse transcription-polymerase chain reaction and immunoblotting and N-ERC/mesothelin concentration in the supernatant of cultured cancer cells by the ELISA system. We also investigated C-ERC/mesothlein expression in human pancreatic ductal carcinoma tissues by immunostaining using 5B2 anti-mesothelin monoclonal antibody and N-ERC/mesothelin concentration in sera obtained from patients with pancreatic ductal carcinoma via ELISA. In vitro, N-ERC/mesothelin concentration in cell culture medium nearly correlated with the expression level of C-ERC/mesothelin. Although C-ERC/mesothelin was frequently expressed in human pancreatic ductal carcinoma, serum N-ERC/mesothelin concentration of cancer patients was equivalent to healthy controls. N-ERC/mesothelin was not useful as a serum marker of pancreatic ductal carcinoma, but because of frequent expression, C-ERC/mesothelin might be useful as a target of molecular imaging and immunotherapy.
authors.affiliation: Department of Pathology and Oncology, Juntendo University School of Medicine, Tokyo 113-8421, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Inami
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kajino
authors.forename: Masaaki
authors.initials: M
authors.lastname: Abe
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hagiwara
authors.forename: Masahiro
authors.initials: M
authors.lastname: Maeda
authors.forename: Masafumi
authors.initials: M
authors.lastname: Suyama
authors.forename: Sumio
authors.initials: S
authors.lastname: Watanabe
authors.forename: Okio
authors.initials: O
authors.lastname: Hino
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000737:chemistry; D000951:Antigens, Neoplasm / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism*; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D058851:GPI-Linked Proteins; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000097:blood* / Q000378:metabolism*; D000090204:Mesothelin; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; C000715527:MSLN protein, human; D008562:Membrane Glycoproteins; D000090204:Mesothelin