2D-page analysis of Vietnamese colorectal cancer tissue samples

Abstract

Colorectal cancer is one of the five most common cancers in both men and women worldwide. This study aimed to find out the differences in the protein profile of the normal and CRC tissue samples which could aid the finding of potential biomarkers for diagnostics. Protein expression in colorectal carcinoma tissues and their paired normal tissues was examined by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) to identify differentially expressed protein spots. Ten pairs of colorectal cancer tissues and adjacent normal tissues were randomly collected from surgical pathology department, Cho Ray Hospital during the period of March 2014 to December 2014. The protein samples were extracted via sonication by using urea buffer in liquid nitrogen. 2D-PAGE analysis was performed at pH range 4–7 and differentially expressed protein spots were determined by using DECOCON Delta 2D software (version 4.6). We have found significant change in the protein expression between carcinoma and normal tissues. In brief, 68 protein spots on 2D gel images substantially increased or decreased in tumors and normal specimens. Of these, a total of 37 up-regulated spots in carcinoma tissues were detected and a total of 31 down-regulated spots in the normal tissues. Although there have been plenty of methods or techniques to analyze protein from a mixture recently, 2D-PAGE is still powerful in its ability to separate different proteins simultaneously on a single gel. However, via establishing and performing 2D-PAGE in this study, we recognized that this technique is quite powerful but costly and particularly has low reproducibility which produces lots of difficulty in analyzing and extracting valuable data.