Glioblastoma, the most common and aggressive brain tumor in adults, is difficult to treat because this cancer can invade the surrounding brain tissue and spread far beyond the original tumor mass. Researchers from the DZNE, the University Hospital Bonn (UKB), and ImmunoSensation³ at the University of Bonn have observed this infiltration process in the living brain using high-tech microscopy. Their study is based on research in mice with a form of brain tumor that closely resembles human glioblastoma.
The findings, published in the journal *Immunity*, reveal complex and context-dependent interactions between glioblastoma cells and the brain’s immune cells, known as microglia. These cells patrol the tissue in search of threats. The findings suggest that they are not merely passive observers, but actively influence both the containment and spread of the tumor.
The researchers captured these processes using “three-photon microscopy,” which utilizes infrared light. They focused on the “distant infiltration zone.” This area of tissue is located several millimeters away from the primary tumor.
Changing Behavior
Among other things, the team found that the behavior of microglia changed as the tumor spread. When only a few tumor cells were present, the microglia were particularly mobile and highly active in their “surveillance function”—that is, in scanning the brain. However, as infiltration increased, this immune response waned. The researchers also investigated the consequences of deactivating a specific surface receptor through which microglia perceive their environment. Furthermore, they analyzed how a drastic reduction in immune cells affected tumor spread.
“Our data show that interactions between tumor cells and microglia play an important role in the spread of glioblastoma,” says Dr. Felix Nebeling, first author of the study. “Targeting the microglia - for example, with drugs - could therefore be a promising approach to limiting tumor spread and improving treatment outcomes.”
Funding
The study involved the DZNE, the UKB, the University of Bonn, the University Medical Center Mannheim, and University College London.
Publication
Microglia-glioblastoma crosstalk mediates glioblastoma invasion at the far infiltration zone, Felix Nebeling et al., Immunity (2026), DOI: https://doi.org/10.1016/j.immuni.2026.03.010
Contact
Felix Nebeling
Klinik für Neuroonkologie am UKB
DZNE
E-Mail: felix.nebeling@ukbonn.de
