title: Fragments of human oncoprotein MDM2 reveal variable distribution within and on cultivated human hepatoma cells.
abstract: Human oncoprotein MDM2 reveals a MHC class I binding motif HMDM441 characterizing MDM2 as a potential tumor antigen. To analyze the distribution of MDM2 proteins containing this motif in liver cancer cells we produced rabbit anti-HMDM441 serum. The novel antibodies bound to an MDM2 fragment of approximately 55 kDa which lacked the N-terminal region and was present in lysate and supernatant of a human hepatoma cell line overexpressing normal 90-kDa MDM2. The 55-kDa fragment was detected in the cytoplasm and nucleoli and at the nuclear envelope of hepatoma cells, whereas normal hepatocytes were negative. Double-fluorescence labeling indicated that the MDM2 fragments and MHC class I molecules were coexpressed on the surface of the hepatoma cells. Further studies must clarify whether MDM2 fragments containing motif HMDM441 are novel targets of immunotherapy and immunochemical tumor diagnosis.
authors.affiliation: Department of Cytopathology, Georg-August-University, Goettingen, Germany. tschlott@med.uni-goettingen.de
authors.forename: T
authors.initials: T
authors.lastname: Schlott
authors.forename: J G
authors.initials: JG
authors.lastname: Scharf
authors.forename: A
authors.initials: A
authors.lastname: Soruri
authors.forename: A
authors.initials: A
authors.lastname: Fayyazi
authors.forename: C
authors.initials: C
authors.lastname: Griesinger
authors.forename: C
authors.initials: C
authors.lastname: Albrecht
authors.forename: H
authors.initials: H
authors.lastname: Eiffert
authors.forename: M
authors.initials: M
authors.lastname: Droese
mesh_terms: D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2; D014407:Tumor Cells, Cultured
chemical_list: D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2