Identification of Small Proteins and Peptides in the Differentiation of Patients with Intraductal Mucinous Neoplasms of the Pancreas, Chronic Pancreatitis and Pancreatic Adenocarcinoma.

Abstract

There are a limited number of studies investigating the type of serum proteins capable of differentiating intraductal papillary mucinous neoplasms from benign or malignant diseases of the pancreas. To select proteins able to differentiate intraductal papillary mucinous neoplasms from benign and malignant pancreatic disease using semiquantitative proteomics. Serum samples were obtained from 74 patients (19 with type II intraductal papillary mucinous neoplasms, 8 with type I/III intraductal papillary mucinous neoplasms, 24 with chronic pancreatitis, 23 with pancreatic ductal adenocarcinomas) and 21 healthy subjects. Small proteins and peptides were assayed by matrix-assisted laser desorption/ionization for the detection of differentially abundant species possibly related to tumor onset. Serum pancreatic amylase, lipase, carcinoembryonic antigen and carbohydrate antigen 19-9 (CA 19-9) were also assayed. Twenty-six of 84 peaks detected were dysregulated (7 more abundant and 19 less abundant in the type II intraductal papillary mucinous neoplasms, p<0.05). Of the differentially abundant peaks, 17 were commonly dysregulated (3 peaks more abundant and 13 less abundant in type II intraductal papillary mucinous neoplasms, and one at m/z= 9961 at variance), indicating a protein fingerprint shared by types I/III and type II intraductal papillary mucinous neoplasms and pancreatic ductal adenocarcinomas. These results suggest that our approach can be used to differentiate type II intraductal papillary mucinous neoplasms from type I/III neoplasms, and type II intraductal papillary mucinous neoplasms from pancreatic ductal adenocarcinomas.