Background: This study was carried out to identify the aberrantly methylated-differentially expressed genes in gastric cancer (GC).
Methods: We downloaded data of gene expression microarrays GSE118916 and gene methylation microarrays GSE25869 from the Gene Expression Omnibus (GEO) database. The DEGs and DMGs were analyzed by the limma software package and Venn diagram. The PPI network was mapped and the enrichment analysis was conducted by the DAVID database. GEPIA online tool, Oncomine database, HPA, and cBioPortal tool were used to verify hub genes.
Result: We obtained 110 Hypo-HGs, 9 high-regulation hypomethylation oncogenes, 23 Hyper-LGs, and 2 low-regulation hypermethylation tumor suppressor genes. Hypo-HGs biological process mainly involves cell adhesion and extracellular matrix organization, Hyper-LGs biological process mainly involves response to nicotine and xenobiotic metabolic process. KEGG analysis showed that Hypo-HGs significantly enriched in Focal adhesion, PI3K-Akt signaling pathway, and ECM-receptor interaction. Hyper-LGs significantly enriched in Drug metabolism-cytochrome P450, Chemical carcinogenesis, and Metabolism of xenobiotics by cytochrome P450. The database identified the hub genes were COL1A1, THBS1, COL5A2, COL12A1, and CXCR.
Conclusion: COL1A1, THBS1, COL5A2, COL12A1, and CXCR4 can be used as a target for precise diagnosis and treatment of GC. Focal adhesion, PI3K-Akt signaling pathway, and ECM-receptor interaction are important mechanisms of GC.