Figure 4.
A model for metabolic heterogeneity in solid tumours. Within solid tumours, regional metabolic activities likely vary significantly according to influences of the microenvironment, particularly access to nutrients and oxygen. In the illustrated example, cells located close to vasculature use their favourable access to nutrients and oxygen to feed oncogene-stimulated anabolic pathways. However, gradients of nutrient availability demand that alternative pathways, including macromolecular degradation, are increasingly engaged at more remote sites to support cell viability. Oncogenes may also enhance the cell’s ability to activate these pathways. OAA, oxaloacetate; α-KG, alpha-ketoglutarate; TCA, tricarboxylic acid; BCAA, branched-chain amino acid.