Figure 4. Glucose and glutamine flux to glutamate is reduced in U87 IDH1 mutant cells.

Schematic representation of ¹³C-labeling of glutamate and 2-HG derived from 1-¹³C-glucose and 3-¹³C-glutamine (A). Build-up of 3-¹³C-glutamate (3-¹³C-GLU) and 3-¹³C-2-HG following perfusion of U87IDHwt and U87IDHmut cells with 3-¹³C-glutamine (3-¹³C-GLN) with quantification of 3-¹³C-glutamate production shown in the inset (B). Build-up of 3-¹³C-lactate (3-¹³C-LAC), 4-¹³C-glutamate (4-¹³C-GLU) and a combined signal of 4-¹³C-glutamate and 4-¹³C-2-HG in U87IDHwt and U87IDHmut cells with quantification of the build-up of glutamate in right inset. Left inset illustrates data from cell extracts resolving 2-HG and glutamate (C).