Figure 2.

Metabolic symbiosis of tumor cells. Tumor cells, which are presented in the hypoxic area are addicted to anaerobic glycolysis. They oxidize glucose to pyruvate and lactate, which is then exported from the cell, or oxidized back into pyruvate. Then, lactate is taken up by oxidative tumor cells and oxidized to pyruvate, which fuels oxidative phosphorylation [17]. Intracellular pH homeostasis is maintained by several transporters and pumps facilitating an H⁺ efflux. Monocarboxylate transporter (MCT) facilitates the export of lactate and H⁺, while H⁺ ATPase and V ATPase extrude H⁺ from the cytosol to the extracellular matrix [20]. Ly = lysosome, Mt = mitochondrion, Nu = nucleus, LDHA = lactate dehydrogenase A, LDHB = lactate dehydrogenase B, MCT = monocarboxylate transporter, CA_i = intracellular carbonic anhydrase, CA_e = extracellular carbonic anhydrase. The main figure conception adapted from Brisson et al. (2016), and from Damaghi et al. (2013). Graphical elements adapted from Servier Medical Art.