Construction of cuproptosis signature based on bioinformatics and experimental validation in clear cell renal cell carcinoma.

Background: Cuproptosis was defined as a novel nonapoptotic cell death pathway and its potential function in clear cell renal cell carcinoma (ccRCC) remains unclear.

Methods: We obtained gene expression profiles, somatic mutation and corresponding clinical information of 881 ccRCC samples from 3 cohorts including the cancer genome atlas cohort, GSE29609 cohort and CheckMate 025 cohort. As described in the latest published article, we enrolled 16 genes as cuproptosis-related genes (CRGs). We explored the expression level, variants and copy number variation of the CRGs. Univariate and multi-variate regression were utilized to assess the prognostic significance of the CRGs. Non-negative matrix factorization was used to identify potential subgroup and gene set variation analysis was used to explore the potential biological functions. CIBERSORT, ESTIMATE algorithm and single sample gene set enrichment analysis were used to evaluate the tumor microenvironment. In vitro experiments including CCK-8, transwell and wound healing assays were utilized to explore the potential biological function of DLAT in ccRCC.

Results: We found that except for CDKN2A, the CRGs were positively associated with patients' OS. Cuproptosis cluster, cuproptosis gene cluster and cuproptosis score were established, respectively, and higher cuproptosis score was significantly associated with a worse OS in ccRCC (p < 0.001). The area under the receiver operating characteristic curve of the cuproptosis-related nomogram at 1 year, 3 years, 5 years was 0.858, 0.821 and 0.78, respectively. In addition, we found that the cuproptosis score was positively associated with PDCD1, CTLA4 expression level, thus the cuproptosis score may also reflect the dysfunction of tumor infiltrating immune cells. In vitro experiments indicated that overexpression of DLAT could inhibited the migration and proliferation ability of ccRCC cells.

Conclusion: Our findings identify a novel cuproptosis-related signature and the cuproptosis characteristics may influence the anti-tumor immunity though complex regulating networks, and thus cuproptosis may play a role in developing novel therapeutic target of ccRCC.