title: Discovery of novel bladder cancer biomarkers by comparative urine proteomics using iTRAQ technology.
abstract: A urine sample preparation workflow for the iTRAQ (isobaric tag for relative and absolute quantitation) technique was established. The reproducibility of this platform was evaluated and applied to discover proteins with differential levels between pooled urine samples from nontumor controls and three bladder cancer patient subgroups with different grades/stages (a total of 14 controls and 23 cancer cases in two multiplex iTRAQ runs). Combining the results of two independent clinical sample sets, a total of 638 urine proteins were identified. Among them, 55 proteins consistently showed >2-fold differences in both sample sets. Western blot analyses of individual urine samples confirmed that the levels of apolipoprotein A-I (APOA1), apolipoprotein A-II, heparin cofactor 2 precursor and peroxiredoxin-2 were significantly elevated in bladder cancer urine specimens (n = 25-74). Finally, we quantified APOA1 in a number of urine samples using a commercial ELISA and confirmed again its potential value for diagnosis (n = 126, 94.6% sensitivity and 92.0% specificity at a cutoff value of 11.16 ng/mL) and early detection (n = 71, 83.8% sensitivity and 94.0% specificity). Collectively, our results provide the first iTRAQ-based quantitative profile of bladder cancer urine proteins and represent a valuable resource for the discovery of bladder cancer markers.
authors.affiliation: Molecular Medicine Research Center, Chang Gung University, Taiwan.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Chen
authors.forename: Chien-Lun
authors.initials: CL
authors.lastname: Chen
authors.forename: Hsiao-Wei
authors.initials: HW
authors.lastname: Chen
authors.forename: Ting
authors.initials: T
authors.lastname: Chung
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Wu
authors.forename: Chi-De
authors.initials: CD
authors.lastname: Chen
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Hsu
authors.forename: Meng-Chieh
authors.initials: MC
authors.lastname: Chen
authors.forename: Ke-Hung
authors.initials: KH
authors.lastname: Tsui
authors.forename: Phei-Lang
authors.initials: PL
authors.lastname: Chang
authors.forename: Yu-Sun
authors.initials: YS
authors.lastname: Chang
authors.forename: Jau-Song
authors.initials: JS
authors.lastname: Yu
mesh_terms: D014408:Biomarkers, Tumor / Q000652:urine*; D016022:Case-Control Studies; D006801:Humans; D009363:Neoplasm Proteins / Q000652:urine; D040901:Proteomics / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins