Identification of cuproptosis-related subtypes and tumor microenvironment characteristics in colon cancer

Cuproptosis is a form of regulated cell death, which is characterized by the lethal accumulation of excessive copper in cells. However, its role in colon adenocarcinoma (COAD) remains elusive. Our study aimed to decipher the biological function of cuproptosis-related genes (CRGs) in patients with COAD. The expression data were obtained from The Cancer Genome Atlas, while the Gene Expression Omnibus database was used to verify the results. A total of eight differentially expressed CRGs were selected from patients with COAD. Subsequently, patients were stratified into three subtypes with distinct clinical and biological features. In view of the huge differences in the prognosis between subtypes A and C, we selected them for further study, including the variations in clinical progressions, oncogenic pathways, and immune cell infiltration. For the sake of better evaluation, we also established a cuproptosis index (CI) to quantify the heterogeneity of CRGs expression. Enrichment analysis showed that the high-CI group was enriched in immune activation pathways. Meanwhile, the immunosuppressive cell infiltration and immune checkpoints were elevated in the high-CI group. The CI we constructed had its predicting function in different clinical groups. Besides, we noticed that CRGs, especially CDKN2A, were closely related to the clinical progression in patients with COAD and immune cell infiltration in tumors. Moreover, CDKN2A could become a potential novel target for immunotherapy in the setting of COAD.