Hypoxia drives shared and distinct transcriptomic changes in two invasive glioma stem cell lines

Area of Science:

• Neuro-oncology
• Cancer biology
• Molecular genetics

Background:

• Glioblastoma (GBM) is a deadly brain cancer.
• Tumor hypoxia promotes GBM invasion and aggression.
• GBM exhibits significant molecular and cellular heterogeneity.

Purpose of the Study:

• Investigate hypoxia-induced gene expression and cellular changes in GBM.
• Understand patient-specific responses to hypoxia in GBM.
• Explore hypoxia's role in GBM heterogeneity and IDH mutation status.

Main Methods:

• 3D cell culture invasion assays using patient-derived GBM stem cell lines.
• RNA sequencing (RNA-seq) to analyze gene expression.
• Single-cell RNA-seq analysis of glioma patient datasets.

Main Results:

• Hypoxia increased invasiveness in two GBM lines.
• Shared hypoxia response genes involved glucose metabolism, angiogenesis, and autophagy.
• Patient-specific genes related to cell migration and anti-inflammation were identified.
• Hypoxic cells shifted to mesenchymal-like (MES) or astrocyte-like (AC) states.
• IDH-mutant gliomas showed a shift to AC state, while IDH-wildtype gliomas shifted to MES state.

Conclusions:

• Hypoxia triggers diverse, patient-specific gene responses in GBM.
• Tumor microenvironment and IDH status influence hypoxia-driven cellular states.
• Transcriptomic insights offer a foundation for understanding hypoxic niches in gliomas.