Impact of CDKN2A gene expression on colon adenocarcinoma via biosignature analysis

Colorectal adenocarcinoma (COAD) has a poor prognosis. Cyclin-dependent kinase inhibitor 2A (CDKN2A) significantly affects the development and progression of various human tumors. However, the significance and pathological mechanisms of CDKN2A in COAD remain to be elucidated. We assessed expression levels, clinical significance, biological function, co-expressed genes, and enrichment of related pathways of CDKN2A in COAD using various databases, including The University of Alabama at Birmingham Cancer Data Analysis Portal, Gene Expression Profiling Interactive Analysis, Tumor Immune Estimation Resource, Human Protein Atlas, STRING, GeneMANIA, cBioPortal, and Linked Omics. Our investigation showed that CDKN2A was highly expressed in colon adenocarcinomas (P < .001). It is weakly expressed or not expressed in normal tissues. The survival time of patients with colon adenocarcinoma with high CDKN2A expression is significantly shorter than that of patients with low expression levels (P = .011). There was a significant positive correlation between the expression level of CDKN2A in colon adenocarcinoma tissues and the infiltration of CD4+ T cells, macrophages, and neutrophils. Moreover, there was a significant negative association between the expression level of CDKN2A in colon adenocarcinoma tissues and B cell infiltration. The ten hub genes included tumor protein 53, V-myc Avian Myelocytomatosis Viral Oncogene Homolog, AKT serine/threonine kinase 1, cyclin-dependent kinase 2, phosphatase and tensin homolog deleted on chromosome ten, cyclin D1, cyclin dependent kinase 4, cyclin dependent kinase inhibitor 1A, catenin beta 1, and B-Raf proto-oncogene, serine/threonine kinase. Mutations in the CDKN2A genome in colon adenocarcinoma reduce survival. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that the differentially expressed genes were enriched in apoptotic signaling pathways and multiple pathways related to metabolic progression. Our results indicate that CDKN2A can be used as a marker of poor prognosis in patients with colon adenocarcinoma. CDKN2A may regulate the occurrence and development of colon adenocarcinomas by influencing immune cell infiltration and metabolic pathways.