Role of monocarboxylate transporters in head and neck squamous cell carcinoma.

Head and Neck tumors are metabolically highly altered solid tumors. Head and Neck cancer cells may utilise different metabolic pathways for energy production. Whereas, glycolysis is the major source coupled with oxidative phosphorylation in a metabolic symbiosis manner that results in the proliferation and metastasis in Head and Neck Cancer. The monocarboxylate transporters (MCTs) constitute a family of 14 members among which MCT1-4 are responsible for transporting monocarboxylates such as l-lactate and pyruvate, and ketone bodies across the plasma membrane. Additionally, MCTs mediate absorption and distribution of monocarboxylates across the cell membrane. Head and Neck cancer cells are highly glycolytic in nature and generate significant amount of lactic acid in the extracellular environment. In such condition, MCTs play a critical role in the regulation of pH, and lactate shuttle maintenance. The intracellular lactate accumulation is harmful for the cells since it drastically lowers the intracellular pH. MCTs facilitate the export of lactate out of the cell. The lactate export mediated by MCTs is crucial for the cancer cells survival. Therefore, targeting MCTs is important and could be a potential therapeutic approach to control growth of the tumor.