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Updated: Jan 12, 2026
Live-3D-Cell Immunocytochemistry Assays of Pediatric Diffuse Midline Glioma
Published on: November 11, 2021
Small Extracellular Vesicles From Radioresistant H3K27M-Pediatric Diffuse Midline Glioma Cells Modulate Tumor
Viral D Oza1,2, Kenan A Flores1, Yelena Chernyavskaya1
1Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA.
Abstract:
Pediatric diffuse midline gliomas with the Histone 3 lysine 27-to-methionine mutation (H3K27M-pDMG) are aggressive brain tumors characterized by intrinsic resistance to radiation therapy, the current standard of care. These tumors exhibit significant intratumoral heterogeneity, with distinct subclonal populations likely contributing to therapy resistance. Emerging evidence suggests that small extracellular vesicles (sEV) mediate oncogenic signaling within glioma stem cell populations, yet their role under radiation-induced stress remains poorly understood. In this study, we characterized sEV uptake dynamics among H3K27M-pDMG tumor cells, identified key sEV surface proteins, and demonstrated that sEVs derived from radioresistant (RR) H3K27M-pDMG cells confer radioprotective effects on radiosensitive tumor cells. Molecular profiling revealed that RR-sEVs carry proteins, microRNAs (miRNAs) and metabolites associated with glycolysis, oxidative phosphorylation and DNA repair. Upon uptake, RR-sEVs reprogrammed recipient cells by altering gene expression and metabolic pathways, and enhancing DNA repair and survival following radiation exposure. These findings provide insights into the role of sEV-mediated intratumoral communication as a contributor to radiation resistance in H3K27M-pDMG and suggest potential therapeutic strategies to disrupt this process and enhance radiation efficacy.
Insights
Pediatric brain tumors called H3K27M-pDMG resist radiation. Resistant tumor cells release vesicles that protect sensitive cells, suggesting new therapeutic targets.
Area of Science:
- Neuro-oncology
- Cancer Biology
- Cellular Communication
Background:
- Pediatric diffuse midline gliomas with the H3K27M mutation (H3K27M-pDMG) are aggressive brain tumors.
- These tumors inherently resist radiation therapy, the standard treatment.
- Intratumoral heterogeneity and cell-to-cell communication via extracellular vesicles may drive resistance.
Purpose of the Study:
- To investigate the role of small extracellular vesicles (sEVs) in radiation resistance of H3K27M-pDMG.
- To characterize sEV uptake, surface proteins, and cargo.
- To determine if sEVs from radioresistant cells can protect radiosensitive cells.
Main Methods:
- Characterized sEV uptake in H3K27M-pDMG cells.
- Identified key sEV surface proteins.
- Performed molecular profiling of sEVs (proteins, miRNAs, metabolites).
- Assessed the impact of RR-sEVs on recipient cell gene expression, metabolism, DNA repair, and survival post-radiation.
Main Results:
- sEVs from radioresistant (RR) H3K27M-pDMG cells conferred radioprotective effects on radiosensitive cells.
- RR-sEVs were enriched with molecules involved in glycolysis, oxidative phosphorylation, and DNA repair.
- Uptake of RR-sEVs reprogrammed recipient cells, enhancing their survival after radiation exposure.
Conclusions:
- sEV-mediated communication contributes to radiation resistance in H3K27M-pDMG.
- RR-sEVs promote survival by altering recipient cell metabolism and DNA repair.
- Targeting sEV pathways could be a strategy to overcome radiation resistance in these pediatric brain tumors.
