Fructose, the simple sugar better known for sweetening sodas, is now in the spotlight for a far more sinister role. Scientists at Northwestern Medicine report that fructose metabolism inside brain immune cells helps glioblastoma tumors grow in mice, and that removing a key fructose transporter slowed tumor progression and extended survival in laboratory models. The work focuses on microglia, the brain’s resident macrophages, and suggests the tumor microenvironment may hijack a sugar pathway to blunt immune attack. The findings are still early and preclinical, but the researchers say the data reveal a metabolic vulnerability that could eventually offer a fresh therapeutic angle.
According to Crain's Chicago Business, the study authors found that microglia are the predominant expressers of the fructose transporter SLC2A5, also called GLUT5, and that mice engineered without that transporter survived longer after glioma implantation. The Crain's report, published March 18, 2026, framed the work as a rare new angle on one of the most stubborn and lethal brain cancers.
What the team did in mice
The research was posted as a detailed preprint to bioRxiv, where the authors describe experiments that used orthotopic glioma models and genetic deletion of the GLUT5 or SLC2A5 transporter. In those studies, mice lacking SLC2A5 in brain resident myeloid cells showed slower tumor growth and a measurable survival benefit. Immune profiling suggested that exposure to fructose pushed microglia toward a less phagocytic, more immunosuppressive state that could help tumors evade clearance. The authors acknowledge that additional validation is needed, but argue that microglial fructose handling is biologically significant for glioblastoma progression.
How this fits with prior work
Laboratory research published in Nature Communications had already shown that glioblastoma cells can switch from glucose to fructose metabolism under stress and that components of the fructose pathway, including GLUT5, can fuel tumor growth. That 2022 study described an ATF4-driven program that increases expression of fructolytic genes, providing a molecular explanation for how tumors survive low glucose conditions. Taken together, the two papers suggest that both tumor cells and tumor-associated immune cells can tap fructose as an alternate fuel that supports malignancy.
Therapeutic takeaways and caveats
The researchers point to the transporter GLUT5 and downstream fructolytic enzymes as possible drug targets, while emphasizing that the evidence is still preclinical and preliminary. The Human Protein Atlas maps SLC2A5 expression to macrophages and microglia and notes enrichment in glioblastoma tissue, which supports the biological plausibility of the target but does not establish clinical benefit. Clinicians caution that these laboratory findings do not justify diet changes for patients at this stage; turning a mouse model vulnerability into a safe and effective human therapy will require substantially more studies and formal clinical testing.
Next steps laid out by the investigators include validating the results in additional models, testing pharmacologic inhibitors of fructose uptake, and exploring whether fructose-related signatures can predict prognosis or treatment response. The microglia-focused angle adds to a growing body of metabolic research that could reshape how scientists hunt for weak spots in glioblastoma, but any translation into human treatment is expected to take time.
