The Function and Mechanism of OXCT1 in Tumor Progression as a Critical Ketone Body Metabolic Enzyme

3-Ketoacid CoA-transferase 1 (OXCT1) is a homodimeric mitochondrial matrix enzyme essential for ketone body metabolism. It catalyzes the reversible transfer of coenzyme A from succinyl-CoA to acetoacetate, playing a central role in extrahepatic ketone body catabolism. Accumulating evidence indicates that OXCT1 is dysregulated in various cancers, where it functions as an oncogene, driving tumor progression by modulating proliferation, metastasis, apoptosis, autophagy, and drug resistance. Its overexpression is associated with aggressive tumor behavior, metabolic adaptation, and poor clinical outcomes. This review systematically summarizes the molecular structure, biological functions, and regulatory mechanisms of OXCT1, highlighting its multifaceted roles in tumorigenesis and progression. Furthermore, we discuss its potential as a diagnostic biomarker, prognostic indicator, and therapeutic target, providing novel insights for developing OXCT1-based anticancer strategies.