Purpose
To identify the key genes and epigenetics biomarkers in HCV-cirrhosis based on informatics analysis of 4 GEO datasets.
Methods
After downloaded GEO datasets from NCBI, two GEO datasets (GSE6764 and GSE14323) were used to screen for the differentially expressed genes (DEGs) by limma package in R. Then DEGs were applied for Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis by clusterProfiler package in R. Protein-protein interaction network was constructed by cytoscape to identify the hub genes of HCV-cirrhosis. DNA methylation dataset GSE60753 was analyzed by ChAMP package in R to identify the differentially methylated genes (DMGs). Cross-analysis of DEGs and DMGs were performed to identify the genes differentially expression and methylation, and further more indicated the methylation of them.
Results
357 DEGs and 8830 DMGs were identified in HCV-cirrhosis. Functional analysis of DEGs obtained pathways that may involved in the pathgenesis of HCV-cirrhosis, including focal adhesion, influenza A, ECM-receptor interaction, protein digestion and absorption, etc. Cross-analysis of DEGs and DMGs identified 212 genes that changed in mRNA level and methylation status, and most of them were methylated in genebodies, but not CpG island. PPI construction in cytoscape revealed 25 hub genes in GEGs, and 5 of which were further analyzed for their probability as markers of HCV-cirrhosis by ROC curve and validation in another GEO dataset.
Conclusions
Our study identified the key genes in HCV-cirrhosis patient, which may provide new approach for clarifying the mechanism and new therapy of HCV-cirrhosis.