title: ERC/mesothelin is expressed in human gastric cancer tissues and cell lines.
abstract: ERC/mesothelin is expressed in mesothelioma and other malignancies. The ERC/mesothelin gene (MSLN) encodes a 71-kDa precursor protein, which is cleaved to yield 31-kDa N-terminal (N-ERC/mesothelin) and 40-kDa C-terminal (C-ERC/mesothelin) proteins. N-ERC/mesothelin is a soluble protein and has been reported to be a diagnostic serum marker of mesothelioma and ovarian cancer. Gastric cancer tissue also expresses C-ERC/mesothelin, but the significance of serum N-ERC levels for diagnosing gastric cancer has not yet been studied. We examined the latter issue in the present study as well as C-ERC/mesothelin expression in human gastric cancer tissues and cell lines. We immunohistochemically examined C-ERC/mesothelin expression in tissue samples from 50 cases of gastric cancer, and we also assessed the C-ERC/mesothelin expression in 6 gastric cancer cell lines (MKN-1, MKN-7, MKN-74, NUGC-3, NUGC-4 and TMK-1) using reverse transcription-polymerase chain reaction, flow cytometry, immunohistochemistry and immunoblotting. We also examined the N-ERC/mesothelin concentrations in the supernatants of cultured cells and in the sera of gastric cancer patients using an enzyme-linked immunosorbent assay (ELISA). N-ERC/mesothelin was detected in the supernatants of 3 gastric cancer cell lines (MKN-1, NUGC-4 and TMK-1) by ELISA, but its concentration in the sera of gastric cancer patients was almost same as that observed in the sera of the normal controls. In the gastric cancer tissues, C-ERC/mesothelin expression was associated with lymphatic invasion. N-ERC/mesothelin was secreted into the supernatants of gastric cancer cell lines, but does not appear to be a useful serum marker of gastric cancer.
authors.affiliation: Department of Surgery, Juntendo Shizuoka Hospital, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Ito
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kajino
authors.forename: Masaaki
authors.initials: M
authors.lastname: Abe
authors.forename: Koichi
authors.initials: K
authors.lastname: Sato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Maekawa
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Sakurada
authors.forename: Hajime
authors.initials: H
authors.lastname: Orita
authors.forename: Ryo
authors.initials: R
authors.lastname: Wada
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kajiyama
authors.forename: Okio
authors.initials: O
authors.lastname: Hino
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D045744:Cell Line, Tumor; D005260:Female; D058851:GPI-Linked Proteins / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D000090204:Mesothelin; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000097:blood / Q000235:genetics / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; C000715527:MSLN protein, human; D000090204:Mesothelin