Measurement of 13 C turnover into glutamate and glutamine pools in brain tumor patients

FEBS Lett. 2017 Nov;591(21):3548-3554. doi: 10.1002/1873-3468.12867. Epub 2017 Oct 27.


Malignant brain tumors are known to utilize acetate as an alternate carbon source in the citric acid cycle for their bioenergetics. 13 C NMR-based isotopomer analysis has been used to measure turnover of 13 C-acetate carbons into glutamate and glutamine pools in tumors. Plasma from the patients infused with [1,2-13 C]acetate further revealed the presence of 13 C isotopomers of glutamine, glucose, and lactate in the circulation that were generated due to metabolism of [1,2-13 C]acetate by peripheral organs. In the tumor cells, [4-13 C] and [3,4-13 C]glutamate and glutamine isotopomers were generated from blood-borne 13 C-labeled glucose and lactate which were formed due to [1,2-13 C[acetate metabolism of peripheral tissues. [4,5-13 C] and [3,4,5-13 C]glutamate and glutamine isotopomers were produced from [1,2-13 C]acetyl-CoA that was derived from direct oxidation of [1,2-13 C] acetate in the tumor. Major portion of C4 13 C fractional enrichment of glutamate (93.3 ± 0.02%) and glutamine (90.9 ± 0.03%) were derived from [1,2-13 C]acetate-derived acetyl-CoA.

Keywords: 13C isotopomer; [1,2-13C]acetate; acetyl-CoA; glutamate and glutamine synthesis; peripheral metabolism.

Publication types

  • Letter
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acetates / administration & dosage
  • Acetates / pharmacokinetics
  • Brain Neoplasms / diagnostic imaging
  • Brain Neoplasms / metabolism*
  • Carbon Isotopes / pharmacokinetics
  • Female
  • Glutamic Acid / metabolism*
  • Glutamine / metabolism*
  • Humans
  • Male


  • Acetates
  • Carbon Isotopes
  • Glutamine
  • Glutamic Acid