title: Cellular and tissue distribution of MRK20 murine monoclonal antibody-defined 85-kDa protein in adriamycin-resistant cancer cell lines.
abstract: A murine monoclonal antibody (MAb) specific to adriamycin-resistant K-562 (K-562/ADM) cells, MRK20, was found to react strongly with an 85-kDa protein present in K-562/ADM and adriamycin-resistant ovarian cancer (2780AD) cells. This protein was present at only very low levels in parental cells (K-562 and A2780), methotrexate-resistant K-562 cells (K-562/MTX3, K-562/MTX4 and K-562/MTX5) and cisplatin-resistant ovarian cells (KFr). Immunoelectron microscopically, the protein was found to be located on the cell membrane of K-562/ADM and 2780AD cells. Furthermore, the presence of the protein in various cell lines, normal tissues and surgical materials from patients given no anti-cancer agents was examined by immunocytochemistry and flow cytometry. MRK20 reacted with granulocytes, monocytes and endothelial cells in various tissues, but did not react with tissue macrophages. This 85-kDa protein recognized by MRK20 seems to be the second multidrug-resistance gene-encoded product appearing in adriamycin-resistant cancer cells, following the characterization of 170-180-kDa glycoprotein, and may be important for elucidating the multidrug-resistance mechanism relevant to adrimycin and Vinca alkaloids.
authors.affiliation: Department of Pathology, University of Tokyo.
authors.forename: I
authors.initials: I
authors.lastname: Sugawara
authors.forename: E
authors.initials: E
authors.lastname: Ohkochi
authors.forename: H
authors.initials: H
authors.lastname: Hamada
authors.forename: T
authors.initials: T
authors.lastname: Tsuruo
authors.forename: S
authors.initials: S
authors.lastname: Mori
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000818:Animals; D000911:Antibodies, Monoclonal; D004317:Doxorubicin / Q000494:pharmacology*; D004351:Drug Resistance; D004727:Endothelium / Q000032:analysis; D015151:Immunoblotting; D007951:Leukemia, Myeloid / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000032:analysis; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D009363:Neoplasm Proteins / Q000032:analysis* / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000911:Antibodies, Monoclonal; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D004317:Doxorubicin