Comprehensive pan-cancer analysis reveals SIRT5 is a predictive biomarker for prognosis and immunotherapy response

Sirtuin 5 (SIRT5) is a promising therapeutic target involved in regulating multiple metabolic pathways in cells and organisms. The role of SIRT5 in cancer is currently unclear, and a comprehensive systematic pan-cancer analysis is required to explore its value in diagnosis, prognosis, and immune function. We investigated the role of SIRT5 in tumorigenesis, diagnosis, prognosis, metabolic pathways, the immune microenvironment, and pan-cancer therapeutic response. Moreover, we explored chemicals affecting the expression of SIRT5 and computed the relationship between SIRT5 and drug sensitivity. Finally, the role of SIRT5 in melanoma was analyzed using a series of experiments in vitro and in vivo. We found that SIRT5 is differentially expressed and shows early diagnostic value in various tumors and that somatic cell copy number alterations and DNA methylation contribute to its aberrant expression. SIRT5 expression correlates with clinical features. Besides, it is negatively (positively) correlated with several metabolic pathways and positively (negatively) correlated with several important metastasis-related and immune-related pathways. High SIRT5 expression predicts poor (or good) prognosis in various tumors and can affect drug sensitivity. We also demonstrated that SIRT5 expression significantly correlates with immunomodulator-associated molecules, lymphocyte subpopulation infiltration, and immunotherapeutic response biomarkers. In addition, we showed that SIRT5 is differentially expressed in immunotherapy cohorts. In addition, we explored various chemicals that may affect SIRT5 expression. In conclusion, we demonstrated that SIRT5 is a key pathogenic gene that promotes melanoma progression. Our study provides a systematic analysis of SIRT5 and its regulatory genes. SIRT5 has excellent diagnostic and prognostic capabilities for many cancers. This may remodel the tumor microenvironment. The potential of SIRT5-based cancer therapies is emphasized and helps predict the response to immunotherapy.