Isaac Marin-Valencia1, Steve K. Cho2,
Levi B. Good2, Ashish Jindal3, Juan M. Pascual2,4,
Ralph J. DeBerardinis1, Robert M. Bachoo2, Elizabeth A.
Maher5, Craig R. Malloy3,6
1Pediatrics, UT
Southwestern Medical Center, Dallas, TX, United States; 2Neurology,
UT Southwestern Medical Center, Dallas, TX, United States; 3Advanced
Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United
States; 4Physiology, UT Southwestern Medical Center, Dallas, TX,
United States; 5Internal Medicine, UT Southwestern Medical Center,
Dallas, TX, United States; 6Radiology, UT Southwestern Medical
Center, Dallas, TX, United States
Increased flux through the pentose phosphate pathway (PPP) is required to support the high metabolic demands of cancer. Using an orthotopic murine model of glioblastoma (GBM) and renal cell carcinoma (RCC) metastatic to the brain, we compared the relative activity of PPP vs. glycolysis in both tumors and their respective surrounding brains using [1,2-13C2]glucose. The ratio of [3-13C]lactate/[2,3-13C2]lactate ratio was similar between tumors and surrounding brains, suggesting that much of the lactate in both tumors exchanges slowly with glycolytic intermediates or that the flux into PPP increases in proportion to glycolysis.