Scientists Discover Oligodendrocytes Drive Glioblastoma Growth

Unveiling a New Mechanism in Glioblastoma Progression

Researchers have uncovered a pivotal mechanism by which glioblastoma (GBM), the most aggressive form of brain cancer, leverages normal brain cells to sustain its growth. Published in Neuron, the study reveals that oligodendrocytes—cells traditionally considered supportive for nerve fibers—actively contribute to tumor progression by interacting with cancer cells. This finding challenges prior assumptions about their role and suggests new therapeutic strategies targeting this interaction. The research, led by scientists at McMaster University and The Hospital for Sick Children (SickKids), emphasizes the dynamic relationship between tumor cells and the brain’s microenvironment, indicating that disrupting this connection could hinder GBM growth.

Building on Prior Research

“reactive oligodendrocytes—cells altered by injury or disease—release pro-tumorigenic cytokines, including CCL5, which bind to the CCR5 receptor on glioma stem-like cells (GSCs).”

The study builds on earlier work by Sheila Singh and Jason Moffat, whose 2024 Nature Medicine research demonstrated how GBM cells exploit developmental pathways to invade healthy tissue. This latest study expands on that by identifying a specific signaling pathway involving the CCL5/CCR5 axis. According to the findings, reactive oligodendrocytes—cells altered by injury or disease—release pro-tumorigenic cytokines, including CCL5, which bind to the CCR5 receptor on glioma stem-like cells (GSCs). This interaction creates a feedback loop that enhances tumor survival and proliferation, highlighting the tumor’s ability to repurpose normal cellular processes for its benefit.

Analyzing the Tumor Microenvironment

The research employed advanced techniques to analyze the tumor microenvironment. Syngeneic mouse models, genetically identical to the host, were used to simulate human GBM progression, enabling precise observation of tumor behavior without immune rejection. Single-cell transcriptomics allowed the team to examine gene expression patterns across individual cells, revealing that oligodendrocytes near tumors shift from their typical supportive role to a pro-tumorigenic state. Cytokine profiling identified inflammatory signals that trigger this transformation, with fractalkine (CX3CL1/CX3CR1) signaling priming oligodendrocytes to secrete factors sustaining tumor growth. Spatial transcriptomics and immunohistochemistry further mapped the distribution of these cells, showing their role in creating a supportive niche for GBM cells.

Identifying a Reactive Oligodendrocyte State

A key discovery was the identification of an interferon (IFN)-induced reactive oligodendrocyte (OL) state, similar to responses in demyelinating inflammation and trauma. This state, enriched in central nervous system malignancies, represents a critical shift in OL behavior that supports tumor growth. The study’s authors constructed a pan-disease human OL meta-atlas, a comprehensive map of oligodendrocyte diversity across conditions, providing insights into how OLs adapt to pathological environments. This work underscores the importance of understanding OL heterogeneity in GBM.

Experimental Insights and Therapeutic Potential

“In laboratory models, inhibiting CCR5 or administering Maraviroc significantly reduced GSC stemness and extended survival in GBM mice.”

The study also included experimental data on genetic knockdown of CCR5 and treatment with Maraviroc. In laboratory models, inhibiting CCR5 or administering Maraviroc significantly reduced GSC stemness and extended survival in GBM mice. These results suggest targeting the CCL5/CCR5 pathway could disrupt the tumor’s ability to sustain growth and resist treatment. The HIV drug Maraviroc, already approved for HIV, is now being evaluated as a potential repurposed therapy for GBM, offering a promising clinical translation pathway.

Funding and Future Directions

The study was supported by the 2020 William Donald Nash Brain Tumour Research Fellowship and the Canadian Institutes for Health Research. The fellowship, awarded to researchers at McMaster University, funded investigations into GBM’s microenvironment, while the Canadian Institutes for Health Research (CIHR) provided resources for interdisciplinary collaboration and translational research. Moving forward, researchers aim to translate these findings into clinical applications, exploring other drugs targeting the CCL5/CCR5 pathway and potential combinations with existing therapies to improve patient outcomes.