Identification of Potential Biomarkers for Colorectal Cancer Using Bioinformatics Analysis

Abstract

Background Colorectal cancer (CRC) is the most common malignant tumor of the intestine, and its incidence and mortality rate are at the forefront. Early diagnosis and intervention of CRC is of great significance. however, there is a lack of precise diagnostic biomarkers. We aim to explore potential biomarkers for CRC and provide a new treatment idea for CRC. Methods We first identified differentially expressed genes (DEGs) in 26 colorectal tumor tissue samples and 26 matched non-tumor tissue samples in the GSE25070 dataset. We then performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs using the Database for Annotation Visualization and Integrated Discovery (DAVID). We further constructed protein-protein interaction (PPI) networks of DEGs using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and screened 10 hub genes using Cytoscape software. GO and KEGG enrichment analysis of hub genes was done by the WEB-based GEne SeT AnaLysis Toolkit (WebGestalt). Finally, we analyzed the expression levels and survival of hub genes using the Gene Expression Profiling Interactive Analysis (GEPIA) database. Results We obtained 756 DEGS (254 upregulated genes and 502 downregulated genes) from the GSE25070 dataset, and DEGs were mainly enriched in inflammatory response, neutrophil chemotaxis, and cytokine-cytokine receptor. Ten hub genes were identified, including five upregulated genes (VEGFA, IL1B, MMP9, CXCL8, and CCND1) and five downregulated genes (MAPK3, ADH1A, SLC26A3, ADH1C, and UGT1A8). Five upregulated genes were highly expressed in CRC patients, and IL1B and CXCL8 genes were significantly associated with overall survival in colorectal cancer patients, and high expression of IL1B and CXCL8 had a greater survival advantage. Conclusion IL1B and CXCL8 are potential biomarkers for CRC.