title: Comparative Proteomic Analysis of Whole-Gut Lavage Fluid and Pancreatic Juice Reveals a Less Invasive Method of Sampling Pancreatic Secretions.
abstract: OBJECTIVE
  There are currently no reliable, non-invasive screening tests for pancreatic ductal adenocarcinoma. The fluid secreted from the pancreatic ductal system ("pancreatic juice") has been well-studied as a potential source of cancer biomarkers. However, it is invasive to collect. We recently observed that the proteomic profile of intestinal effluent from the bowel in response to administration of an oral bowel preparation solution (also known as whole-gut lavage fluid, WGLF) contains large amounts of pancreas-derived proteins. We therefore hypothesized that the proteomic profile is similar to that of pancreatic juice. In this study, we compared the proteomic profiles of 77 patients undergoing routine colonoscopy with the profiles of 19 samples of pure pancreatic juice collected during surgery.
  
  
  METHODS
  WGLF was collected from patients undergoing routine colonoscopy, and pancreatic juice was collected from patients undergoing pancreatic surgery. Protein was isolated from both samples using an optimized method and analyzed by LC-MS/MS. Identified proteins were compared between samples and groups to determine similarity of the two fluids. We then compared our results with literature reports of pancreatic juice-based studies to determine similarity.
  
  
  RESULTS
  We found 104 proteins in our pancreatic juice samples, of which 90% were also found in our WGLF samples. The majority (67%) of the total proteins found in the WGLF were common to pancreatic juice, with intestine-specific proteins making up a smaller proportion.
  
  
  CONCLUSIONS
  WGLF and pancreatic juice appear to have similar proteomic profiles. This supports the notion that WGLF is a non-invasive, surrogate bio-fluid for pancreatic juice. Further studies are required to further elucidate its role in the diagnosis of pancreatic cancer.
authors.affiliation: Proteomics and Mass Spectrometry Laboratory, University of South Alabama Mitchell Cancer Institute, Mobile, Alabama, USA.
authors.forename: Jana M
authors.initials: JM
authors.lastname: Rocker
authors.affiliation: Proteomics and Mass Spectrometry Laboratory, University of South Alabama Mitchell Cancer Institute, Mobile, Alabama, USA.|Department of Surgery, University of South Alabama, Mobile, Alabama, USA.
authors.forename: Marcus C
authors.initials: MC
authors.lastname: Tan
authors.affiliation: Cancer Surgery of Mobile, PC, Mobile, Alabama, USA.
authors.forename: Lee W
authors.initials: LW
authors.lastname: Thompson
authors.affiliation: Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Carlo M
authors.initials: CM
authors.lastname: Contreras
authors.affiliation: Division of Gastroenterology, University of South Alabama, College of Medicine, Mobile, Alabama, USA.
authors.forename: Jack A
authors.initials: JA
authors.lastname: DiPalma
authors.affiliation: Proteomics and Mass Spectrometry Laboratory, University of South Alabama Mitchell Cancer Institute, Mobile, Alabama, USA.
authors.forename: Lewis K
authors.initials: LK
authors.lastname: Pannell