Bioinformatics analysis of colorectal cancer genome microarray based on GEO database

Abstract

Objective To explore the key genes and pathogenesis of colorectal cancer (CRC) by bioinformatics analysis. Methods The microarray data of whole genome expression profiles containing normal colorectal tissue, colorectal adenoma, and colorectal cancer were downloaded from the GEO and identified differential expression genes (DEGs) of colorectal cancer by GCBI. The DEGs were analyzed by gene ontology (GO), KEGG pathway, and protein-protein interaction (PPI) network. Then, the interaction model was established by cytoscape using PPI results. Results A total of 740 DEGs (248 upregulated and 492 downregulated) were obtained when gene expression gradually increased or gradually reduced in normal colorectal tissue, colorectal adenoma tissue, and colorectal cancer tissue. GO analysis results showed that DEGs were significantly enriched in metabolic processes, cell proliferation, regulation of signaling, and RNA polymerase II transcription factor activity. KEGG pathway analysis showed the DEGs were enriched in transcriptional misregulation in cancer, cell cycle and p53 signaling pathway and so on. The key genes related to colorectal cancer including CDK1, MCM2, CDC6, CCNA1, CCNB2, CDKN1B, ORC1, E2F1, CHEK1, PCNA were obtained from the interaction model. Then, KEGG pathway analysis showed the key genes were enriched in cell cycle, viral carcinogenesis, pathways in cancer, p53 signaling pathway, and PI3K-Akt signaling pathway. Conclusion The key genes and their related pathways in colorectal cancer were obtained from bioinformatics analysis of gene chip data and provided the basis for follow-up study. Key words: Bioinformatics; Colorectal cancer; Microarray; Differential expression genes