Targeting Radiation-Induced Glioma-Initiating Cells in Patient-Derived Glioblastoma

Area of Science:

• Neuro-oncology
• Cancer Biology
• Drug Discovery

Background:

• Glioblastoma (GB) is an aggressive brain cancer with high recurrence rates after standard treatment.
• GB tumors contain hierarchical glioma-initiating cells (GICs) responsible for tumor growth and resistance.
• Radiotherapy can induce non-tumorigenic cells to become GICs, contributing to recurrence.

Purpose of the Study:

• To identify small molecules that inhibit radiation-induced phenotypic conversion in glioblastoma cells.
• To find novel therapeutic strategies for targeting glioblastoma heterogeneity and recurrence.

Main Methods:

• High-throughput screening of NCI's Cancer Therapy Evaluation Program (CTEP) compounds.
• Utilized fluorescent reporters to distinguish glioma-initiating cells (GICs) from non-tumor-initiating cells.
• Tested compounds in combination with radiation across various glioblastoma cell lines.

Main Results:

• Selumetinib was identified as a compound that prevents radiation-induced phenotypic conversion.
• Selumetinib, combined with radiation, reduced GIC stemness.
• Differential effects on non-tumorigenic cell viability were observed.

Conclusions:

• Repurposing FDA-approved compounds like selumetinib offers a rapid approach to target glioblastoma heterogeneity.
• Targeting radiation-induced cell conversion and GICs is crucial for overcoming glioblastoma treatment resistance.
• This strategy holds promise for rapid clinical implementation to improve glioblastoma outcomes.