Identifying Effective Pathways and Genes in Colorectal Cancer according to Stage by Analyzing RNA Sequencing Data

Introduction: Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide.Numerous studies have demonstrated dysregulated gene expression in CRC. However, comprehensiveinvestigations are still needed to clarify the underlying biological pathways disrupted by these dysregulatedgenes. This study was designed to identify differentially expressed genes (DEGs) common across all CRCstages compared to normal samples, as well as to identify hub genes and their related pathways.Methods: RNA sequencing data were downloaded from the TCGA database. Samples were classified into fourstages, and DEGs between each stage and normal samples were identified. Genes present in all four groupswere selected for further analysis. Gene enrichment analyses were performed using the DAVID database tovalidate the data. A protein-protein interaction (PPI) network was constructed, and hub genes were identifiedusing the CytoHubba plugin. The UALCAN database was used to perform in silico validation of the potentialgenes of interest.Results: A total of 2,899 genes were commonly expressed across all four groups. Biological pathway analysisshowed that these genes are enriched in known CRC pathways. PPI network analysis and hub gene identificationusing the CytoHubba plugin highlighted key hub genes. Validation through the UALCAN database confirmedthe relevance of these genes, and enrichment analysis demonstrated their association with G protein-coupledreceptor (GPCR) signaling.Conclusion: The hub genes are functionally associated with the GPCR signaling pathway. Given the welldocumentedinvolvement of the GPCR pathway in various cancers, especially CRC, further research on thesegenes and pathways is essential to enhance our understanding of this disease