Astrocyte-Glioblastoma Stem Cell Interactions via Extracellular Vesicles Contribute to Distinct Vascular Structures

Area of Science:

• Oncology
• Cell Biology
• Biomaterials

Background:

• Glioblastoma (GBM) is a deadly brain tumor known for its heterogeneity and resistance to therapy.
• Cancer stem-like cells (CSCs) in GBM drive tumor recurrence, often residing in perivascular niches.
• Interactions between GBM cells and surrounding stromal cells, like astrocytes, are crucial for tumor progression.

Purpose of the Study:

• To investigate the communication mechanisms between glioblastoma cells and astrocytes within a specialized microenvironment.
• To explore the role of extracellular vesicles (EVs) in mediating these cell-cell interactions.
• To establish a hydrogel-based co-culture model for studying glioblastoma-stroma crosstalk.

Main Methods:

• Co-culture of glioblastoma KMG4 cells and immortalized human astrocytes (NHA-TS) on hydrogels.
• Analysis of gene expression related to stemness and epithelial-mesenchymal transition.
• Characterization of extracellular vesicles (EVs) derived from glioblastoma and astrocytes.
• Proteomic analysis of co-cultured EVs and spatial transcriptomic analysis of human GBM tissue.
• Assessment of pericyte-associated gene expression in glioblastoma cells cultured on specific hydrogels.

Main Results:

• Co-culture on hydrogels induced stemness and epithelial-mesenchymal transition-related genes in glioblastoma cells.
• Astrocytic EVs modulated glioblastoma stemness, while glioblastoma EVs promoted vascular development genes in astrocytes.
• Proteomic analysis identified COL1A1 and THBS1 in EVs from co-cultures, with similar expression in perivascular regions of human GBM tissue.
• Glioblastoma cells cultured on hydrogels upregulated pericyte-associated genes, suggesting differentiation towards a pericyte-like phenotype.

Conclusions:

• Extracellular vesicle-mediated communication between glioblastoma cells and astrocytes is vital for inducing stemness and promoting perivascular niche formation.
• Glioblastoma cells can differentiate towards a pericyte-like phenotype, contributing to microvascular proliferation within the tumor microenvironment.
• The hydrogel co-culture system offers an effective platform for dissecting tumor-stroma interactions in glioblastoma.