Differential proteomic analysis of pancreatic juice in pancreatic cancer patients / 中华消化杂志

ABSTRACT

Objective To analyze the differential expression of proteins among patients with pancreatic cancer,chronic pancreatitis and choledocholithiasis in order to find potential biomarkers for diagnosis of pancreatic cancer and to differentiate pancreatic cancer from chronic pancreatitis. Methods The pancreatic juice were connected from 5 pancreatic cancer patients,6 chronic pancreatitis patients and 3 choledocholi-thiasis patients by naso-pancreatic drainage using endoscopic retrograde cholanglopancreatography(ERCP).The proteins in pooled pancreatic juice were separated by two-dimensional gel electrophoresis (2-DE).The differential expression of proteins were analyzed by image analysis software and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).Results ①There were 35-200 ml of pancreatic juice collected,and protein concentration were ranged from 0.8 to 4.6 μg/μl.The 2-DE showed that the protein spots in pancreatic cancer,chronic pancreatitis and choledocholithiasis juice were 196±12,209±15 and 199±10,respectively.The matched proteins among three groups all exceeded 75%.②MALDI-TOF-MS revealed that the expression of chain A of a covalent dimer of transthyretin in pancreatic cancer was up-regulated(＞2-fold)while the expressions of chain A of crystal structure of lipid-free human apolipoproteinA-1,chain of human lithostathin and regenerating islet-derived 1 beta precursor were down-regulated. Conclusions Protein spectra are different in patients with pancreatic cancer,chronic pancreatitis and choledocholithiasis.Transthyretin,apolipoproteinA-1,human lithostathin and regenerating islet-derived 1 beta might be the biomarkers of human pancreatic cancer and may be useful in distinguishing pancreatic cancer from chronic panceatitis.