Preliminary study on two-dimensional gel electrophoresis of human pancreatic juice for proteome analysis

Abstract

Objective To establish an optimal method of two-dimensional gel electrophoresis (2-DE) for proteomic analysis of human pancreatic juice (pj) on the basis of former work and explore the feasibility of differential proteomic analysis of human pancreatic juice by the use of mixed pancreatic juice samples. Methods Pj samples from 5 pancreatic cancer patients (two cases were pathologically diagnosed moderately differentiated adenocarcinoma and intraduetal papilloma canceration respectively,three cases were diagnosed by inageology and clinical manifestations) and 6 chronic pancreatitis pa-tients were included in this study. Pj samples were collected by naso-pancreatic drainage during endo-scopic retrograde cholangiopancreatography. 2-DE was conducted on one pj sample of chronic panerea-titis by improving sample preparation techniques. Compositions of rehydration solutions and methods of isoelectric focusing and 2-DE maps were compared with those got from former 2-DE method. 2-DE method and 2-DE maps of single pj sample and mixed pj samples of the same pancreatic disease were also compared by the optimized method of 2-DE. Results With the improved 2-DE method and when 200 μg protein of pancreatic juice was loaded, about 280 protein spots could be successfully separated with better differentiation rate as compared with the former method. There was higher similarity (>75%)between the 2-DE maps of single pj sample and mixed pj samples of the same pancreatic disease. Conclusion Optimized method of 2-DE has reliable effect and the comparison of 2-DE maps of mixed pj samples of different pancreatic diseases would become the basis of differential proteomic analysis of human pancreatic juice. Key words: Human; Pancreatic juiee; Proteomics; Two-dimensional gel electrophoresis