More lactate, please

摘要

Traditionally, lactate, the end product of glycolysis, has been regarded more as a metabolic waste than a fuel in tumour cells. However, a recent study in Cell describes the metabolism of lactate in human lung tumours in vivo, showing that exogenous lactate is consumed and used, predominantly over glucose, as a respiratory fuel. During glycolysis, glucose, a main metabolic fuel in many tumour cells, is converted into 3-phosphoglycerate (3PG) and then via pyruvate into lactate. The fate of glucose in tumours was studied by stable isotope labelling. Intra-operative infusions of glucose, labelled with heavy carbons ([~(13)C]glucose), into patients with non-small-cell lung cancer (NSCLC) was followed by subsequent analysis of the ~(13)C content in 3PG and lactate from tumour tissue, and revealed two groups of patients with distinct labelling patterns.