Construction of cuproptosis‑associated prognostic signature in colon adenocarcinoma based on bioinformatics and RT‑qPCR analysis

Colon adenocarcinoma (COAD) is the most common pathological subtype of colon cancer with a high degree of malignancy. Cuproptosis is a newly discovered copper-dependent cell death pattern distinguished from all the other known programmed cell death. Hence, it can be used as a potential therapeutic target for cancer. The present study aimed to clarify the relationship between cuproptosis and prognosis of COAD. The variations of 12 cuproptosis-associated genes based on 623 patients with COAD were comprehensively identified. It was found that 8 out of 12 were differentially expressed in tumors and normal tissues and CDKN2A showed a higher prognostic value. Therefore, two molecular subtypes were explored and the subtype A, with higher expression of cuproptosis-associated genes, showed more enrichment of immune pathways and survival advantage over those with lower cuproptosis-associated genes expression. The risk score and a nomogram predicting pattern were constructed to quantify a single patient and the risk score could serve as an independent prognostic factor by multivariate Cox regression analysis (P<0.001, HR: 1.350, 95% CI: 1.189-1.534). The expression levels of key prognostic genes (PMM2, ACOX1, KDM3A, HSPB1, PPARGC1A, UPK3B and EPHB2) was analyzed by HCT-116 colon cancer cells and HT-29 colorectal cancer cells using reverse transcription-quantitative PCR. The high-risk group, characterized by higher immune infiltration, increased microsatellite instability-high, high tumor mutation burden and high expression level of immune checkpoints, indicated higher drug sensitivity. In conclusion, our analysis confirms the potential role of cuproptosis-associated genes in the prognosis of COAD and it will provide new ideas for immunotherapy.