title: Local radiotherapy increases the level of autoantibodies to ribosomal             P0 protein but not to heat shock proteins, extracellular matrix molecules and             EGFR/ErbB2 receptors in prostate cancer patients.
abstract: Prostate cancer is a common cancer among men in developed countries. Although             hormonotherapy and radiotherapy (RT) represent valid therapies for prostate cancer             treatment, novel immunological approaches have been explored. The development             of clinical trials employing cancer vaccines has indicated that immune response             to tumor antigens can be boosted and that vaccine administration can improve patient             survival. Immune response to tumor antigens could also be enhanced after standard             therapies. In the present study, we determined the occurrence of antibodies to             extracellular matrix (ECM) molecules, heat shock protein (HSP), ribosomal P0 protein,             EGFR, ErbB2 and prostate-specific antigen (PSA) in 35 prostate cancer patients             prior to and following local RT and hormonotherapy. We demonstrated that immunity             to P0, ECM molecules [collagens (C) CI, CIII, CV, fibronectin (FN) and laminin             (LM)] and to HSP90 was associated with malignancy in untreated patients. None             of the patient sera showed antibodies to EGFR, while 2 and 1 patients showed reactivity             to ErbB2 and PSA, respectively. We also demonstrated that 8 months after therapy             the IgG serum levels to CI, CIII, FN and HSP90 significantly decreased. Conversely,             the level of P0 autoantibodies increased after therapy in 10 patients. Five of             the 10 patients with increased levels of P0 autoantibodies were treated with RT             plus hormonotherapy. Treatment of patients did not change the levels of antibodies             against EGFR, ErbB2 and PSA. Our results indicated that the modification of antibody             level to self molecules after standard treatment of prostate cancer patients is             influenced by the type of antigen. Ribosomal P0 protein appears to be a high immunogenic             antigen and its immunogenicity increases following RT. In addition, 10 patients             with increased levels of autoantibodies to P0 showed PSA mean levels lower than             the remaining 25 patients at 18 months. This study may contribute to a better             understanding of the immunobiological behavior of prostate cancer patients following             standard treatment.
authors.affiliation: Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Ingrosso
authors.forename: Massimo
authors.initials: M
authors.lastname: Fantini
authors.forename: Alessandra
authors.initials: A
authors.lastname: Nardi
authors.forename: Monica
authors.initials: M
authors.lastname: Benvenuto
authors.forename: Pamela
authors.initials: P
authors.lastname: Sacchetti
authors.forename: Laura
authors.initials: L
authors.lastname: Masuelli
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ponti
authors.forename: Giovanni Vanni
authors.initials: GV
authors.lastname: Frajese
authors.forename: Florigio
authors.initials: F
authors.lastname: Lista
authors.forename: Orazio
authors.initials: O
authors.lastname: Schillaci
authors.forename: Riccardo
authors.initials: R
authors.lastname: Santoni
authors.forename: Andrea
authors.initials: A
authors.lastname: Modesti
authors.forename: Roberto
authors.initials: R
authors.lastname: Bei
mesh_terms: D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D016022:Case-Control Studies; D066246:ErbB Receptors / Q000276:immunology*; D016326:Extracellular Matrix Proteins / Q000276:immunology*; D006360:Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D056724:Immunity, Humoral; D007074:Immunoglobulin G / Q000097:blood; D007610:Kallikreins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000276:immunology; D011471:Prostatic Neoplasms / Q000097:blood / Q000276:immunology / Q000532:radiotherapy*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology*; D012269:Ribosomal Proteins / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D066246:ErbB Receptors; D016326:Extracellular Matrix Proteins; D006360:Heat-Shock Proteins; D007074:Immunoglobulin G; D007610:Kallikreins; D017430:Prostate-Specific Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D012269:Ribosomal Proteins; C054675:ribosomal protein P0; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C549870:KLK3 protein, human