Metabolic Interplay between Tumour Cells and Cancer-Associated Fibroblasts (CAFs) under Hypoxia versus Normoxia.

The growth of tumour cells is closely related to cancer-associated fibroblasts (CAFs) present within their microenvironment. CAFs, the most abundant cells in tumour stroma, secrete growth factors that play pivotal roles in tumour cell proliferation, metabolism, angiogenesis and metastasis. Tumour cells adapt to rapid environmental changes from normoxia to hypoxia through metabolic interplay with CAFs. In this mini review, we discuss the role of lactate dehydrogenases (LDHs) and monocarboxylate transporters (MCTs) on the metabolic interplay between tumour cells and CAFs under hypoxia compared to normoxia. The LDHs catalyse the interchange of lactate and pyruvate, whereas MCTs facilitate the influx and efflux of monocarboxylates, especially lactate and pyruvate. To sum up, tumour cells switch their metabolic state between glycolysis and oxidative phosphorylation through metabolic interplay with CAFs, which exhibit the Warburg effect under hypoxia and reverse Warburg effect under normoxia.