title: Identification of plasma biomarker candidates in glioblastoma using an antibody-array-based proteomic approach.
abstract: BACKGROUND
  Glioblastoma multiforme (GBM) is a brain tumour with a very high patient mortality rate, with a median survival of 47 weeks. This might be improved by the identification of novel diagnostic, prognostic and predictive therapy-response biomarkers, preferentially through the monitoring of the patient blood. The aim of this study was to define the impact of GBM in terms of alterations of the plasma protein levels in these patients.
  
  
  METHODS
  We used a commercially available antibody array that includes 656 antibodies to analyse blood plasma samples from 17 healthy volunteers in comparison with 17 blood plasma samples from patients with GBM.
  
  
  RESULTS
  We identified 11 plasma proteins that are statistically most strongly associated with the presence of GBM. These proteins belong to three functional signalling pathways: T-cell signalling and immune responses; cell adhesion and migration; and cell-cycle control and apoptosis. Thus, we can consider this identified set of proteins as potential diagnostic biomarker candidates for GBM. In addition, a set of 16 plasma proteins were significantly associated with the overall survival of these patients with GBM. Guanine nucleotide binding protein alpha (GNAO1) was associated with both GBM presence and survival of patients with GBM.
  
  
  CONCLUSIONS
  Antibody array analysis represents a useful tool for the screening of plasma samples for potential cancer biomarker candidates in small-scale exploratory experiments; however, clinical validation of these candidates requires their further evaluation in a larger study on an independent cohort of patients.
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia.
authors.forename: Klemen
authors.initials: K
authors.lastname: Zupancic
authors.affiliation: Department of Entomology, National Institute of Biology, Ljubljana, Slovenia.
authors.forename: Andrej
authors.initials: A
authors.lastname: Blejec
authors.affiliation: Blood Transfusion Centre, Immunohaematology Department Ljubljana, Slovenia.
authors.forename: Ana
authors.initials: A
authors.lastname: Herman
authors.affiliation: Educell Ltd., Trzin, Slovenia.
authors.forename: Matija
authors.initials: M
authors.lastname: Veber
authors.affiliation: Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia.
authors.forename: Urska
authors.initials: U
authors.lastname: Verbovsek
authors.affiliation: Department of Neurosurgery, University Medical Centre Ljubljana, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Marjan
authors.initials: M
authors.lastname: Korsic
authors.affiliation: Educell Ltd., Trzin, Slovenia.
authors.forename: Miomir
authors.initials: M
authors.lastname: Knezevic
authors.affiliation: Blood Transfusion Centre, Immunohaematology Department Ljubljana, Slovenia.
authors.forename: Primoz
authors.initials: P
authors.lastname: Rozman
authors.affiliation: Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia ; Faculty of Chemistry and Chemical Engineering, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Tamara Lah
authors.initials: TL
authors.lastname: Turnsek
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Gruden
authors.affiliation: Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia.
authors.forename: Helena
authors.initials: H
authors.lastname: Motaln
keywords: antibody array; biomarker; glioblastoma; plasma; proteomics