The study reveals that some brain cells, previously believed to only support normal nerve function, can actually assist glioblastoma in growing and spreading. These cells send signals that strengthen tumor cells. When scientists blocked this communication in laboratory models, tumor growth dropped significantly.

The findings also highlight a potential treatment opportunity. Researchers found that a drug already used to treat HIV might be able to interfere with this process, offering a new option for patients who currently have very limited treatment choices. Glioblastoma has a poor outlook, with survival often measured in months.

Study Details and Research Teams

The research was published Neuron and conducted by scientists at McMaster University and The Hospital for Sick Children (SickKids). The co-first authors are Kui Zhai, a research associate in the Singh Lab at McMaster, and Nick Mikolajewicz, who was a postdoctoral fellow in the Moffat Lab at SickKids during the study.

“Glioblastoma isn’t just a mass of cancer cells, it’s an ecosystem,” says Sheila Singh, co-senior author of the study and professor of surgery at McMaster University. “By decoding how these cells talk to each other, we’ve found a vulnerability that could be targeted with a drug that’s already on the market,” adds Singh, who is also director of the Centre for Discovery in Cancer Research at McMaster.

Oligodendrocytes and Tumor Communication

Scientists have long known that glioblastoma relies on networks of interacting cells to grow. Interrupting these connections can slow the disease. This study focused on identifying which specific brain cells are involved.

The team found that oligodendrocytes, which normally protect nerve fibers, can change their behavior and begin supporting tumor growth. These cells communicate with cancer cells through a defined signaling system, creating conditions that help the tumor survive and expand. When this signaling was blocked in lab models, tumor growth slowed considerably, showing how essential this interaction is.

Existing HIV Drug Offers New Hope

A key part of this signaling process involves a receptor called CCR5. This receptor is already targeted by an HIV drug known as Maraviroc. Because this medication is already approved and widely used, it could potentially be repurposed more quickly as a treatment for glioblastoma.

“The cellular ecosystem within glioblastoma is far more dynamic than previously understood. In uncovering an important piece of the cancer’s biology, we also identified a potential therapeutic target that could be addressed with an existing drug. This finding opens a promising path to explore whether blocking this pathway can speed progress toward new treatment options for patients,” said Jason Moffat, co-senior author of the study, senior scientist and head of the Genetics & Genome Biology program at SickKids.

Building on Earlier Discoveries

These findings build on earlier work by Singh and Moffat published in Nature Medicine in 2024, which showed that cancer cells can take advantage of pathways normally used during brain development to spread. Together, these studies point toward a new direction in glioblastoma research focused on disrupting the communication systems that tumors rely on.

The research was supported by the 2020 William Donald Nash Brain Tumour Research Fellowship and the Canadian Institutes for Health Research. Singh is a Tier 1 Canada Research Chair in Human Cancer Stem Cell Biology, and Moffat holds the GlaxoSmithKline Chair in Genetics & Genome Biology at The Hospital for Sick Children.