Mitochondrial metabolite transporters at the crossroads of metabolic reprogramming, epigenetic regulation and therapeutic vulnerabilities in colorectal cancer.

Metabolic reprogramming is a defining hallmark of CRC. The Warburg effect is the principal metabolic feature of CRC cells, wherein glucose is preferentially catabolized into lactate to sustain accelerated proliferation. In parallel, CRC cells exhibit strong glutamine reliance to replenish tricarboxylic acid (TCA) cycle intermediates required for adenosine triphosphate (ATP) production, lipid biosynthesis and redox homeostasis. Consequently, mitochondria play a central role in supporting the augmented biosynthetic and energetic demands beyond basal energy homeostasis. In this regard, the mitochondrial pyruvate carrier (MPC), mitochondrial citrate carrier (CIC) and the mitochondrial glutamine carrier (SLC1A5_var) located in the inner mitochondrial membrane, are emerging areas of investigation in CRC metabolism. MPC is frequently lost or downregulated in CRC, whereas CIC was found to be upregulated and promote CRC growth and survival. In contrast, SLC1A5_var has been reported to exhibit elevated expression in colon cancer cells. Recent evidence indicates that its inhibition reduces CRC cell viability; however, its specific role in CRC progression remains to be elucidated. Notably, these transporters may influence the metabolic-epigenetic landscape of CRC through metabolite-dependent regulation of chromatin and transcriptional processes. This review highlights current insights into mitochondrial metabolite transporters in CRC and their potential metabolic and epigenetic implications. Thus, elucidating the roles of these transporters may provide novel therapeutic strategies for CRC management.