title: Inflammation: an important parameter in the search of prostate cancer biomarkers.
abstract: BACKGROUND
  A more specific and early diagnostics for prostate cancer (PCa) is highly desirable. In this study, being inflammation the focus of our effort, serum protein profiles were analyzed in order to investigate if this parameter could interfere with the search of discriminating proteins between PCa and benign prostatic hyperplasia (BPH).
  
  
  METHODS
  Patients with clinical suspect of PCa and candidates for trans-rectal ultrasound guided prostate biopsy (TRUS) were enrolled. Histological specimens were examined in order to grade and classify the tumor, identify BPH and detect inflammation. Surface Enhanced Laser Desorption/Ionization-Time of Flight-Mass Spectrometry (SELDI-ToF-MS) and two-dimensional gel electrophoresis (2-DE) coupled with Liquid Chromatography-MS/MS (LC-MS/MS) were used to analyze immuno-depleted serum samples from patients with PCa and BPH.
  
  
  RESULTS
  The comparison between PCa (with and without inflammation) and BPH (with and without inflammation) serum samples by SELDI-ToF-MS analysis did not show differences in protein expression, while changes were only observed when the concomitant presence of inflammation was taken into consideration. In fact, when samples with histological sign of inflammation were excluded, 20 significantly different protein peaks were detected. Subsequent comparisons (PCa with inflammation vs PCa without inflammation, and BPH with inflammation vs BPH without inflammation) showed that 16 proteins appeared to be modified in the presence of inflammation, while 4 protein peaks were not modified. With 2-DE analysis, comparing PCa without inflammation vs PCa with inflammation, and BPH without inflammation vs the same condition in the presence of inflammation, were identified 29 and 25 differentially expressed protein spots, respectively. Excluding samples with inflammation the comparison between PCa vs BPH showed 9 unique PCa proteins, 4 of which overlapped with those previously identified in the presence of inflammation, while other 2 were new proteins, not identified in our previous comparisons.
  
  
  CONCLUSIONS
  The present study indicates that inflammation might be a confounding parameter during the proteomic research of candidate biomarkers of PCa. These results indicate that some possible biomarker-candidate proteins are strongly influenced by the presence of inflammation, hence only a well-selected protein pattern should be considered for potential marker of PCa.
authors.affiliation: Department of Diagnostic Medicine, Clinic and Public Health, Proteomic Lab, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Bergamini
authors.affiliation: Department of Diagnostic Medicine, Clinic and Public Health, Proteomic Lab, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bellei
authors.affiliation: Section of Pathologic Anatomy, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Reggiani Bonetti
authors.affiliation: Department of Diagnostic Medicine, Clinic and Public Health, Proteomic Lab, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Monari
authors.affiliation: Department of Diagnostic Medicine, Clinic and Public Health, Proteomic Lab, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Aurora
authors.initials: A
authors.lastname: Cuoghi
authors.affiliation: Department of Urology, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Borelli
authors.affiliation: Department of Urology, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Sighinolfi
authors.affiliation: Department of Urology, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Bianchi
authors.affiliation: Department of Biochemistry, Medical Faculty, Akdeniz University, Antalya, Turkey.
authors.forename: Tomris
authors.initials: T
authors.lastname: Ozben
authors.affiliation: Department of Diagnostic Medicine, Clinic and Public Health, Proteomic Lab, University Hospital of Modena and Reggio Emilia, Via del Pozzo 71, 41124 Modena, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Tomasi
keywords: 2-DE; Inflammation; Prostate cancer biomarkers; Proteomics; SELDI-ToF-MS