SIRT5/7 desuccinylation in cancer: linking metabolism, immunity, and drug resistance.
The sirtuin family proteins SIRT5 and SIRT7, as NAD⁺-dependent lysine desuccinylases, exert critical yet context-dependent roles in cancer progression. Mitochondrial SIRT5 functions as a metabolic rheostat, desuccinylating key enzymes in the TCA cycle, glutaminolysis, and fatty acid oxidation to maintain redox balance and bioenergetic output. Conversely, nuclear SIRT7 acts as an epigenetic modulator, regulating chromatin architecture and DNA damage repair via histone and non-histone desuccinylation. These compartmentalized activities converge to coordinate a metabolic-epigenetic axis that drives tumor adaptation to metabolic stress, evasion of immune surveillance, and therapeutic resistance. Given this functional duality, biomarker-guided therapeutic strategies are imperative. This review synthesizes the emerging roles of SIRT5/7-mediated desuccinylation in cancer metabolism, immunity, and drug resistance, highlighting their potential as targets for synergistic metabolic-immunotherapy interventions.