Note: Single-source report; awaiting corroboration.
Glioblastoma, the most aggressive form of adult brain cancer, remains difficult to treat partly because the tumor microenvironment suppresses the immune response, according to NIH-funded research. Microglia, the brain's immune cells, use fructose for energy through the GLUT5 protein.
Researchers led by Dr. Jason Miska at Northwestern University found that fructose is abundant in mouse brains and that microglia are the only immune cells in glioblastoma that metabolize fructose. They also observed that glioblastoma tissues express more GLUT5 than normal brain tissue. In vitro, fructose reduced microglial inflammatory response and their ability to engulf glioma cells, a key immune function.
In mouse models, genetic deletion of GLUT5 in microglia decreased fructose metabolism, increased activation of microglia and CD8+ T cells, and improved survival in most glioma-bearing mice. However, this survival benefit was absent in mice lacking mature T or B cells, highlighting the importance of these immune cells in the observed effects.
These findings suggest that limiting fructose use in microglia may restore immune function against glioblastoma and improve outcomes, potentially informing future immunotherapy strategies for this challenging cancer.
The study was published on March 17, 2026, in the Proceedings of the National Academy of Sciences.