title: The Ca-MOv18 molecule, a cell-surface marker of human ovarian carcinomas, is anchored to the cell membrane by phosphatidylinositol.
abstract: The structure of the 38 kD cell surface glycoprotein identified by the monoclonal antibody MOv18 and specifically expressed by human ovarian carcinomas has been investigated at a molecular level. The ovarian carcinoma cell line IGROV-1, which expresses high levels of Ca-MOv18, was treated with the phosphatidylinositol-specific phospholipase C from B. thuringiensis. The phospholipase C specifically released most of the Ca-MOv18 molecules as shown by flow cytometric analysis of the treated cells and by radioimmunometric assays of the corresponding supernatants. Consistent with the known structure of other phosphatidylinositol-linked molecules, Ca-MOv18 was biosynthetically labeled by [3H]ethanolamine and the labeled molecules were immunoprecipitated from the supernatant fo the phospholipase C treated cells. Evidence that Ca-MOv18 is anchored to the cell membrane via phosphatidylinositol may prove to be relevant in current investigations regarding the biological and clinical significance of this tumor marker.
authors.affiliation: Laboratory of Immunology, Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Alberti
authors.forename: S
authors.initials: S
authors.lastname: Miotti
authors.forename: M
authors.initials: M
authors.lastname: Fornaro
authors.forename: L
authors.initials: L
authors.lastname: Mantovani
authors.forename: S
authors.initials: S
authors.lastname: Walter
authors.forename: S
authors.initials: S
authors.lastname: Canevari
authors.forename: S
authors.initials: S
authors.lastname: Menard
authors.forename: M I
authors.initials: MI
authors.lastname: Colnaghi
mesh_terms: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry / Q000276:immunology; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008970:Molecular Weight; D010051:Ovarian Neoplasms; D010716:Phosphatidylinositols / Q000032:analysis*
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D010716:Phosphatidylinositols