Decoding Colorectal Cancer: Key Genes and Pathways in the Chinese Population Revealed

Background: As the leading cause of cancer-related deaths globally, colorectal cancer (CRC) ranks third in prevalence. Gene Expression Omnibus (GEO) offers clinicians and bioinformaticians an accessible platform for genomic research across various cancer types, with a particular emphasis on CRC. Objective: We aim to uncover key genes and pathways in the Chinese CRC population. Methods: We identified differentially expressed genes (DEGs) in CRC utilizing four microarray datasets sourced from the GEO database, all specifically from the Chinese population. Functional enrichment analysis was conducted to uncover the molecular mechanisms at play in CRC. The PPI network and CytoHubba tools were employed to identify key genes linked to CRC, with further validation through databases such as Gene Expression Profiling Interactive Analysis (GEPIA), ONCOMINE, and the Human Protein Atlas (HPA). Results: Our analysis identified 188 DEGs with overlapping significance, comprising 97 upregulated and 91 downregulated genes. Gene Ontology (GO) analysis indicated that upregulated DEGs were predominantly involved in the extracellular space. In contrast, the downregulated ones were linked to bicarbonate transport and extracellular exosomes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis highlighted the involvement of upregulated DEGs in cytokine-cytokine receptor interactions and the TNF signaling pathway. In contrast, the downregulated genes were associated with nitrogen metabolism and bicarbonate reclamation in the proximal tubule. Notably, the transcriptional levels of CCL20, CDC20, CXCL1, CXCL2, CXCL5, NEK2, and PPBP were elevated in CRC tissues compared to normal tissues. In addition, CXCL12 showed a decreased expression. Additionally, the translational levels of CDC20 and PPBP were found to be higher in CRC tissues. Conclusions: Eight genes (CCL20, CDC20, CXCL1, CXCL12, CXCL2, CXCL5, NEK2, and PPBP) were identified as potential diagnostic indicators for CRC. The identified pathways, such as cytokine-cytokine receptor interactions and TNF signaling, along with nitrogen metabolism and bicarbonate reclamation in the proximal tubule, are hypothesized to have a role in the genesis and progression of CRC. This study provides unique insights into the etiology and progression of CRC within the Chinese population.