Identification of Prognostic Related Hub Genes in Clear-Cell Renal Cell Carcinoma via Bioinformatical Analysis

Objective To identify new genes that correlate with prognosis of clear-cell renal cell carcinoma (ccRCC) via bioinformatics analysis. Methods The gene expression profiles of 62 ccRCC and 54 normal kidney tissues were available from the Gene Expression Omnibus database: GSE12606, GSE36895 and GSE66272. The differentially expressed genes were screened with GEO2R and J Venn online tools. Functional annotation including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) was applied to identify the possible function of the hub genes involved in prognosis of ccRCC. In protein protein interaction network (PPI network), the STRING online tool was used to visualize the network of the differentially expressed genes, and the core gene was selected by MCODE App in Cytoscape software. Finally, GEPIA Survival Plot was performed to assess genes associated with worse survival. Results We totally found 648 differentially expressed genes, including 222 up-regulated genes and 426 down-regulated genes. PPI network showed that in 28 up-regulated genes 7 (CCNE2, CDK1, CDC6, CCNB2, BUB1, TTK and PTTG1) enriched in cell cycle and 4 genes (CCNE2, CDK1, CCNB2 and RRM2) enriched in p53 signaling pathway. GEPIA Survival Plot assay revealed that ccRCC patients carrying CDK1, CCNB2, RRM2, BUB1, and PTTG1 had a worse survival. GEPIA Box Plot showed that BUB1, CCNB2, PTTG1, and RRM2 were over expressed in the ccRCC tissues in contrast to the normal tissues (P<0.05). Conclusion ccRCC patients with the four up-regulated differentially expressed genes including BUB1, CCNB2, PTTG1, and RRM2 might manifest a poor prognosis.