title: Identification of markers for the selection of patients undergoing renal cell carcinoma-specific immunotherapy.
abstract: Renal cell carcinoma (RCC) represents the most common malignant tumor in the kidney and is resistant to conventional therapies. The diagnosis of RCC is often delayed leading to progression and metastatic spread of the disease. Thus, validated markers for the early detection of the disease as well as selection of patients undergoing specific therapy is urgently needed. Using treatment with the monoclonal antibody (mAb) G250 as a model, proteome-based strategies were implemented for the identification of markers which may allow the discrimination between responders and nonresponders prior to application of G250-mediated immunotherapy. Flow cytometry revealed G250 surface expression in approximately 40% of RCC cell lines, but not in the normal kidney epithelium cell lines. G250 expression levels significantly varied thereby distinguishing between low, medium and high G250 expressing cell lines. Comparisons of two-dimensional gel electrophoresis expression profiles of untreated RCC cell lines versus RCC cell lines treated with a mAb directed against G250 and the characterization of differentially expressed proteins by mass spectrometry and/or Edman sequencing led to the identification of proteins such as chaperones, antigen processing components, transporters, metabolic enzymes, cytoskeletal proteins and unknown proteins. Moreover, some of these differentially expressed proteins matched with immunoreactive proteins previously identified by proteome analysis combined with immunoblotting using sera from healthy donors and RCC patients, a technique called PROTEOMEX. Immunohistochemical analysis of a panel of surgically removed RCC lesions and corresponding normal kidney epithelium confirmed the heterogeneous expression pattern found by proteome-based technologies. In conclusion, conventional proteome analysis as well as PROTEOMEX could be successfully employed for the identification of markers which may allow the selection of patients prior to specific immunotherapy.
authors.affiliation: The Johannes Gutenberg-University, IIIrd Department of Internal Medicine, Mainz, Germany. b.seliger@3-med.klinik.uni-mainz.de
authors.forename: Barbara
authors.initials: B
authors.lastname: Seliger
authors.forename: Matthias
authors.initials: M
authors.lastname: Menig
authors.forename: Rudolf
authors.initials: R
authors.lastname: Lichtenfels
authors.forename: Derek
authors.initials: D
authors.lastname: Atkins
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bukur
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Halder
authors.forename: Michael
authors.initials: M
authors.lastname: Kersten
authors.forename: Alois
authors.initials: A
authors.lastname: Harder
authors.forename: Angelika
authors.initials: A
authors.lastname: Ackermann
authors.forename: Joachim
authors.initials: J
authors.lastname: Beck
authors.forename: Bernd
authors.initials: B
authors.lastname: Muehlenweg
authors.forename: Walburgis
authors.initials: W
authors.lastname: Brenner
authors.forename: Sebastian
authors.initials: S
authors.lastname: Melchior
authors.forename: Roland
authors.initials: R
authors.lastname: Kellner
authors.forename: Friedrich
authors.initials: F
authors.lastname: Lottspeich
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism / Q000627:therapeutic use; D014408:Biomarkers, Tumor; D002292:Carcinoma, Renal Cell / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D005434:Flow Cytometry; D006801:Humans; D007167:Immunotherapy; D007680:Kidney Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D013058:Mass Spectrometry; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D020539:Sequence Analysis, Protein
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; C106533:G250 monoclonal antibody; D011506:Proteins