title: Proteomic analysis of ovarian cancer proximal fluids: validation of elevated peroxiredoxin 1 in patient peripheral circulation.
abstract: BACKGROUND
  Epithelial ovarian cancer (EOC) is the deadliest gynecologic malignancy in the United States. Unfortunately, a validated protein biomarker-screening test to detect early stage disease from peripheral blood has not yet been developed. The present investigation assesses the ability to identify tumor relevant proteins from ovarian cancer proximal fluids, including tissue interstitial fluid (TIF) and corresponding ascites, from patients with papillary serous EOC and translates these findings to targeted blood-based immunoassays.
  
  
  RESULTS
  Paired TIF and ascites collected from four papillary serous EOC patients at the time of surgery underwent immunodepletion, resolution by 1D gel electrophoresis and in-gel digestion for analysis by liquid chromatography-tandem mass spectrometry, which resulted in an aggregate identification of 569 and 171 proteins from TIF and ascites, respectively. Of these, peroxiredoxin I (PRDX1) was selected for validation in serum by ELISA and demonstrated to be present and significantly elevated (p = 0.0188) in 20 EOC patients with a mean level of 26.0 ng/mL (±9.27 SEM) as compared to 4.19 ng/mL (±2.58 SEM) from 16 patients with normal/benign ovarian pathology.
  
  
  CONCLUSIONS
  We have utilized a workflow for harvesting EOC-relevant proximal biofluids, including TIF and ascites, for proteomic analysis. Among the differentially abundant proteins identified from these proximal fluids, PRDX1 was demonstrated to be present in serum and shown by ELISA to be elevated by nearly 6-fold in papillary serous EOC patients relative to normal/benign patients. Our findings demonstrate the facile ability to discover potential EOC-relevant proteins in proximal fluids and confirm their presence in peripheral blood serum. In addition, our finding of elevated levels of PRDX1 in the serum of EOC patients versus normal/benign patients warrants further evaluation as a tumor specific biomarker for EOC.
authors: Division of Gynecologic Oncology, Department of Obstetrics, Gynecology, and Reproductive Sciences at Magee-Womens Hospital of the University of Pittsburgh School of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America.
authors: Ebony R
authors: ER
authors: Hoskins
authors: Brian L
authors: BL
authors: Hood
authors: Mai
authors: M
authors: Sun
authors: Thomas C
authors: TC
authors: Krivak
authors: Robert P
authors: RP
authors: Edwards
authors: Thomas P
authors: TP
authors: Conrads
mesh_terms: D000328:Adult; D000368:Aged; D015153:Blotting, Western; D000077216:Carcinoma, Ovarian Epithelial; D002853:Chromatography, Liquid; D045604:Extracellular Fluid / Q000378:metabolism; D005260:Female; D006801:Humans; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000378:metabolism*; D054464:Peroxiredoxins / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D054464:Peroxiredoxins