A Novel Defined Pyroptosis-Related Gene Prognostic Index for Clear Cell Renal Cell Carcinoma
Abstract Background: Clear cell renal cell carcinoma (ccRCC), a common pathological subtype of renal cancer with high aggressiveness, has been reported to be associated with chronic inflammation. Pyroptosis, a newly discovered inflammatory form of programmed cell death, can aggravate the inflammatory response. However, the influence of pyroptosis-related genes on ccRCC patient outcomes is yet unknown.Methods: In this study, 43 differentially expressed pyroptosis-related hub genes were identified by analysing The Cancer Genome Atlas–Kidney Renal Clear Cell Carcinoma dataset. The risk-score model was selected using the least absolute shrinkage and selection operator Cox regression and Cox multivariate methods, and all patients were divided into two risk subgroups based on the risk score. Prognostic value of the risk-score model was verified through survival curve, receiver operating characteristic curve and risk curve. Gene ontology and Kyoto Encyclopaedia of Genes and Genomes analyses suggested that the differentially expressed genes between the two subgroups were enriched in immune-mediated categories. Furthermore, the relationship between the risk-score model and ESTIMATE immune score and immunophenoscore was analysed. Finally, Nomogram was constructed based on the results of cox regression analyses. Results: The training cohort and the validation cohort enrolled 346 and 148 ccRCC patients respectively. The risk-score model was constructed by two genes (AIM2 and GSDMB). The area under curve of the ROC curve in two cohorts were both greater than 0.6. The grade and risk score were selected as independent factors and used to construct a nomogram to predict ccRCC patients' survival rate with the c-index of 0.68. Moreover, high-risk score subgroup was associated with a higher immune score and a lower percentage of PBRM1 mutations. The risk score was positively related to the degree of immune infiltration of CD8+ T, T follicular helper, gamma delta T, and regulatory T cells, and patients with a higher risk score were more likely to benefit from immune checkpoint inhibitor therapy. Conclusion: The risk-score model based on pyroptosis-related genes constructed in our study is a promising biomarker to predict the prognosis, molecular and immune characteristics, and immune benefit from immune checkpoint inhibitor therapy in ccRCC patients.