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Objective: Gastric cancer is a multi-stage multiple genes involved in invasive disease, gastric cancer early diagnosis is critical, therefore, particularly important in the early detection of cancer, this study through a comparative analysis of gastric cancer and normal gastric mucosa differentially expressed protein spectrum, Screening and identification of differentially expressed significance of protein molecules, looking for early diagnosis and treatment of cancer molecular markers provide preliminary experimental evidence. Methods: In this study, laser capture microdissection (laser capture microdissection, LCM) technology, access high-purity gastric cancer tissue and normal gastric glandular tissue by isotope iTRAQ labeling and normal gastric mucosa total protein, and then with a strong cation exchange / reversed-phase liquid chromatography (SCX / nanoHPLC) for electrospray ionization tandem mass spectrometry (ESI-MS/MS), obtained two samples of peptides and relative abundance of information through a database search and comparison, identification of differentially expressed proteins . Results: In this study, quantitative proteomics methods to compare poorly differentiated adenocarcinoma of gastric cancer and normal gastric glands gland cell protein differences were identified 319 proteins, of which more than 2-fold differentially expressed in the 88 , was highly expressed in gastric cancer of 12, showed low expression 76. Press the protein function is divided into seven categories: cytoskeletal proteins, chaperones, signal transduction, biological metabolism, apoptosis, protein synthesis and metabolism and other kinds of proteins. 12 kinds of highly expressed proteins are secreted proteins and cytoskeletal proteins such as vimentin, CK18, Decorin, Lumican so low expression of 76 proteins, there is associated with signal transduction proteins such as Septin9, Ras-related protein Rab-44, S100P and so on, there are biological oxidation associated with proteins such as Peroxiredoxins-1, Cytochrome c oxidase subunit 5B, etc., there is protein synthesis associated with proteins such as 60S ribosomal protein L8, Histone H1x etc., there cytoskeletal proteins such as CK19, Cofilin-1, etc., there is the apoptosis-related proteins such as Microtubule-associated protein 1S, Protein-glutamine gamma glutamyltransferase 2, etc., there is associated with the molecular chaperone proteins, such as HSP60, HSP70, HSP90β. Gastric altered expression of the protein may be involved in the occurrence and development of gastric cancer. Conclusions: 1. Combined LCM with iTRAQ quantitative proteomics technology successfully screened differentially expressed proteins in gastric adenocarcinoma were identified 319 proteins, 12 protein is highly expressed in gastric adenocarcinoma, 76 protein expression in gastric adenocarcinoma low. (2) Identification of differentially expressed proteins Ezrin, Septin9, Prdx1, Prdx 6 such as gastric adenocarcinoma tumor marker discovery and molecular mechanism of providing valuable information.
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