The aims of this study were to characterize the proteome of normal pancreatic juice, to analyze the effect of secretin on the normal proteome, and to compare these results with published data from patients with pancreatic cancer.
Paired pancreatic fluid specimens (before and after intravenous secretin stimulation) were obtained during endoscopic pancreatography from 3 patients without significant pancreatic pathology. Proteins were identified and quantified by mass spectrometry-based protein quantification technology. The human RefSeq (NCBI) database was used to compare the data in samples from patients without pancreatic disease with published data from 3 patients with pancreatic cancer.
A total of 285 proteins were identified in normal pancreatic juice. Ninety had sufficient amino acid sequences identified to characterize the protein with a high level of confidence. All 90 proteins were present before and after secretin administration but with altered relative concentrations, usually by 1 to 2 folds, after stimulation. Comparison with 170 published pancreatic cancer proteins yielded an overlap of only 42 proteins.
Normal pancreatic juice contains multiple proteins related to many biological processes. Secretin alters the concentration but not the spectrum of these proteins. The pancreatic juice proteome of patients without pancreatic disease and that of patients with pancreatic cancer differ markedly.
From the *Department of Surgery, Indiana University School of Medicine, Indianapolis; †Indiana University Cancer Center, Indianapolis;‡Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis; §Department of Biostatistics, Monarch LifeSciences LLC, Indianapolis; ∥Department of Medicine, Indiana University School of Medicine, Indianapolis, IN; ¶Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD.
Received for publication March 19, 2010; accepted March 18, 2011.
Reprints: C. Max Schmidt, MD, PhD, MBA, Departments of Surgery and Biochemistry and Molecular Biology, 980 W. Walnut St, R3-C541, Indianapolis, IN 46202 (e-mail: firstname.lastname@example.org).
This work was supported by NIH 1R03CA112629-01A1 (CMS).
Portions of this paper were presented at the Pancreas Club Annual Meeting in Washington, DC, May 20, 2007, and the American Pancreatic Association Meeting in Chicago, Illinois, November 1–3, 2007.
The authors declare no conflict of interest.