Few diagnoses hit a family harder than a brain tumor in a young child.
For one aggressive type, doctors have had almost nothing to offer beyond radiation that holds the disease back for a short while.
A new experiment in mice is now raising hopes that a smarter immune therapy could help.
Scientists at UC San Francisco engineered a therapy that stays switched off in the bloodstream and only activates once it reaches the brain.
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In two mouse models of diffuse midline glioma, the modified cells wiped out the tumors and kept patrolling for over 70 days.
The team reported the results in Science Translational Medicine on October 28, 2026.
The approach is a form of CAR-T therapy. That means immune cells, called T cells, are taken from a patient and reprogrammed to attack cancer.
The method has transformed some blood cancers. But it has struggled against solid brain tumors, where healthy and cancerous tissue sit close together.
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Diffuse midline glioma, or DMG, grows inside the brainstem, which controls breathing, heartbeat and swallowing.
It mostly strikes children between 5 and 10, and median survival is less than a year. There is no curative treatment.
How the new cells know when to switch on
The UCSF team built a two-step sensor into the T cells. First, the cells look for brevican, a protein found almost only in brain tissue.
When they find brevican, they switch on their cancer-killing receptor. That receptor then goes after two proteins commonly carried by DMG cells.
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The team calls the system B-SYNC. Splitting detection from attack keeps the cells quiet in the rest of the body.
It also helps avoid the exhaustion that often cripples CAR-T cells before they reach the tumor.
The work was led by postdoctoral researcher Senthilnath Lakshmanachetty in the lab of Hideho Okada, a UCSF professor of neurological surgery.
What the mice showed
In one experiment, all ten mice that received a single infusion of B-SYNC cells cleared their tumors.
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Conventional CAR-T cells, used as a comparison, failed to control the disease.
The cells also held the line for weeks. When the researchers reintroduced tumor cells nearly seven weeks after the first treatment, the engineered T cells recognized the threat and rejected the new tumors.
"This preclinical data is very promising. Mice with DMG are being cured, and we are incredibly excited to bring this therapy to the children and young adults we care for," said Sabine Mueller in a UCSF announcement. Mueller directs the UCSF Pediatric Brain Tumor Center.
These are mouse results, not patient results. Encouraging mouse data in cancer research often does not survive the move into humans.
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The team is preparing a first human trial at UCSF Health. It is expected to open in April 2027.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.