Unveiling the Prognostic Significance and Immunological Characteristics of T Cell Marked Ubiquitination Related Genes in Colorectal Adenocarcinoma via Single-Cell and bulk RNA Sequencing

Background T cell activation and function play a crucial role in antitumor therapy, particularly in the context of the rise of immunotherapy. This process is tightly controlled by ubiquitination, and the potential involvement of genes linked to both T cells and ubiquitination in colorectal cancer development is still uncertain. Method In this study, we identified T cell Marked Ubiquitination Related genes (TCMURGs) from single-cell sequencing data and mRNA data of COAD (Colorectal Adenocarcinoma). We analyzed the expression and mutation characteristics of TCMURGs in COAD, identified COAD molecular subtypes through clustering analysis, and analyzed the differences in biological behavior between subtypes and the variations in the tumor microenvironment. We utilized LASSO regression and Xgboost machine learning methods to screen for feature genes, constructed a risk-prognostic model, and assessed the impact of the model genes on prognosis through SHapley Additive exPlanations (SHAP) analysis. We predicted the patient's immune status and the effectiveness of drug treatment through immune cell infiltration, Tumor Mutational Burden (TMB) analysis, and drug sensitivity analysis. We validated the expression of key genes in clinical samples using immunohistochemistry results from the Human Protein Atlas (HPA) database and Quantitative PCR(qPCR). Result Through multi-omics data analysis, we identified seven TCMURGs and identified two COAD subtypes. There were significant differences in biological behavior and immune microenvironment between two subtypes. The B subtype is biologically enriched in ubiquitination proteasome, T cell receptor signaling pathway and antigen processing and presentation. Ultimately, we established a COAD prognosis risk model using five feature genes. SHAP analysis further explained the impact of the model genes on prognosis. We found that patients in the high-risk group were more likely to form an inhibitory immune microenvironment, and survival analysis suggested a poorer prognosis. We also predicted that some targeted drugs such as Afatinib, Erlotinib, Gefitinib, Lapatinib, Osimertinib, and Sorafenib were more effective in low-risk patients. Finally, the expression of these key genes was validated in clinical samples, and the results were consistent. Conclusions Our research findings provide evidence for the role of TCMURGs in COAD and offer new insights for personalized and precise treatment of COAD.