Monocarboxylate transporter 1 and 4 (MCT1/MCT4)

Monocarboxylate transporters 1 and 4 (MCT1 and MCT4) are transmembrane proteins belonging to the solute carrier family 16 (SLC16) that facilitate the proton-coupled transport of monocarboxylates such as lactate, pyruvate, and ketone bodies across the plasma membrane [UniProt: P53396, O15427]. MCT1 (SLC16A1) typically mediates the uptake of lactate in oxidative cells, while MCT4 (SLC16A3) is specialized for the efflux of lactate in highly glycolytic cells, particularly under hypoxic conditions [PubMed: 22131303]. In the context of the Warburg effect in cancer, these transporters play a critical role in maintaining intracellular pH and metabolic flux by preventing the toxic accumulation of lactate and protons [PubMed: 24510011]. Targeting MCT1 and MCT4 has emerged as a promising therapeutic strategy to disrupt the metabolic symbiosis between glycolytic and oxidative tumor cells, leading to metabolic crisis and cell death [PubMed: 26876174]. Small molecule inhibitors like AZD3965, which targets MCT1, are currently being evaluated in clinical trials for various malignancies [ClinicalTrials.gov: NCT01791595]. Dual inhibition or specific MCT4 targeting is also being explored to overcome resistance mechanisms and enhance anti-tumor efficacy [PubMed: 25691611].

Other names

SLC16A1SLC16A3Solute carrier family 16 member 1Solute carrier family 16 member 3H+/monocarboxylate transporter 1H+/monocarboxylate transporter 4MCT1MCT4

Inhibition of proton-coupled monocarboxylate transport, primarily lactate, leading to intracellular acidification, inhibition of glycolysis, and metabolic exhaustion in cancer cells [PubMed: 24510011].