Fig. 5.

Exogenous 2HG does not influence TCA cycle labeling from U-¹³C glucose. As further support that significant amounts of 2HG are not metabolized into TCA cycle intermediates, we performed an experiment that had a reverse labeling scheme compared to that experiment shown in Fig. 2. U-¹³C glucose was given to cells and the labeling patterns of TCA cycle intermediates monitored as a function of L-2HG, D-2HG, or racemic mixtures of L- and D-2HG administration. Here, we show isotopologue distributions of metabolites from HCT116 R132H/+ cultures given U-¹³C glucose + D-2HG and from parent cultures given U-¹³C glucose and no 2HG. Isotopologue distributions were evaluated for TCA cycle intermediates and related compounds, three of which are displayed. No differences in isotopologue distributions were found to be statistically significant in these experiments (n = 3 per group) or those performed with the L-2HG enantiomer (n = 3 per group) and the racemic mixture of 2HG (n = 3 per group)