title: The utility of isotope-coded protein labeling for prioritization of proteins found in ovarian cancer patient urine.
abstract: Urine offers a number of attractive features as a sample type for biomarker discovery, including noninvasive sampling, quantity and availability, stability, and a narrow dynamic range. In this study we report the first application of isotope coded protein labeling (ICPL), coupled with in-solution isoelectric fractionation and LC-MALDI-TOF/TOF, to examine and prioritize urinary proteins from ovarian cancer patients. Following the definition of stringent exclusion criteria a total of 579 proteins were identified with 43% providing quantitation data. Protein abundance changes were validated for selected proteins by ESI-Qq-TOF MS, following which Western blot and immunohistochemical analysis by tissue microarray was used to explore the biological relevance of the proteins identified. Several established markers (e.g., HE4, osteopontin) were identified at increased levels in ovarian cancer patient urine, validating the approach used; we also identified a number of potential marker candidates (e.g., phosphatidylethanolamine binding protein 1, cell-adhesion molecule 1) previously unreported in the context of ovarian cancer. We conclude that the ICPL strategy for identification and relative quantitation of urine proteins is an appropriate tool for biomarker discovery studies, and can be applied for the selection of potential biomarker candidates for further characterization.
authors: Prince Henry's Institute, Monash Medical Centre, Clayton, Victoria, Australia, 3168.
authors: Adam
authors: A
authors: Rainczuk
authors: Mark
authors: M
authors: Condina
authors: Matthias
authors: M
authors: Pelzing
authors: Sebastiaan
authors: S
authors: Dolman
authors: Jyothsna
authors: J
authors: Rao
authors: Nicole
authors: N
authors: Fairweather
authors: Tom
authors: T
authors: Jobling
authors: Andrew N
authors: AN
authors: Stephens
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D014408:Biomarkers, Tumor / Q000737:chemistry / Q000652:urine*; D016022:Case-Control Studies; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000652:urine; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry / Q000652:urine; D018969:Insulin-Like Growth Factor Binding Proteins / Q000737:chemistry / Q000652:urine; D007553:Isotope Labeling; D008875:Middle Aged; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms / Q000652:urine*; D049488:Phosphatidylethanolamine Binding Protein / Q000737:chemistry / Q000652:urine; D053719:Tandem Mass Spectrometry
chemical_list: D014408:Biomarkers, Tumor; C403514:CADM1 protein, human; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D018969:Insulin-Like Growth Factor Binding Proteins; C511482:PEBP1 protein, human; D049488:Phosphatidylethanolamine Binding Protein; C102529:insulin-like growth factor binding protein-related protein 1