Analysis Of The Differentially Expressed Genes Of Gastric Cancer Gene Chip

Objective:Gene chip is one of the revolutionary developments in the field of molecular biology technology within these 20 years. With the mature of expression profile chip technology,a lot of gene chips and vast amounts of biological information generated. How to use gene chip data from numerous laboratories,and understand the biological significance involved in the numerous and complicated gene expression data is a challenge and target of biologists.Gastric cancer is one of the most common cancers worldwide.Gastric cancer has become the fourth most common malignancy and the second in mortality of total cancers worldwide[1].However,the mechanisms involved in this cancer are still poorly understood. A better understanding of the biology,genetics and molecular mechanisms of gastric cancer would be useful in developing novel targeted approaches for treating this disease. In the study,we used the gene chip data to explore the molecular mechanisms of gastric cancer by biological software.Methods: We downloaded GSE29272 and GSE19826 from GEO(Gene Exprssion Omnibus),each chip data was divided into T(gastric cancer tissue) and N(tissue adjacent to carcinoma) two groups.The GeneSpring GX 11.5 provided a new and intuitive tool for this purpose in detecting differentially expressed genes(DEGs). We got the common up-regulated genes and down-rugulated genes by Venny.Then we used DAVID to investigate the gene ontology,signaling pathways involved in gastric cancer,and mined the function of these genes and signaling pathways,their roles in the occurrence and development of gastric cancer combined with the literature data. Finally,we adopt the real- time PCR technology to verify these differentially expressed genes.Results: We got 91 differentially expressed genes by gene chip data.Among them,56 genes are up-regulated and 35 genes are down-regulated(Differences are all more than 2 times). The results of gene ontology analysis mainly include : Extracellular matrix organization,Cell adhesion,Blood vessel development,Collagen metabolism,et al. The results of signaling pathway enrichment analysis mainly include:ECM-receptor interactions and focal adhesion. The RT-PCR validation results of COL1A1, COL1A2, COL3A1, FN1, THBS2 were consistent with the testing results of gene chip,which proved the reliability of experimental data.Conclusion: The two signaling pathways of ECM- receptor interactions and focal adhesion are the main pathogenesis of gastric cancer.