Proteomics analysis of Her-2/neu-linked protein profiles in tumor microenvironment

Abstract

In this study, proteomics had been employed to analyze the HER-2/neu-linked protein profiles in breast tumor microenvironment. Proteome profiles of the HER-2/neu-positive and -negative breast tumors were generated with two-dimensional gel electrophoresis. Combinations of different pH ranges of IPG dry-strips were used to achieve high resolution separation of the proteins. With the aid of MALDI-TOF/TOF and bioinformatics tools, 38 differentially expressed proteins were identified. Gene Ontology analysis revealed that these proteins were mainly involved in intermediary metabolism, structural organization, molecular transportation, protein folding and assembly, anti-oxidative and cellular detoxification, RNA processing and signaling pathway inhibitions. Western blots analysis using more clinical specimens displayed a similar trend of expression as those observed on 2DE images, confirming our proteomics results. Besides, immunohistochemistry on tissue microarray had provided statistically significant differential expression of the proteins. With these results, the differential regulation of protein expression by HER-2/neu in breast cancer is firmly established.