Abstract 4868: Modelling glioblastoma sensitivity to irradiation with a patient derived xenograft-derived 3D platform

Key Points

• The aim is to evaluate glioblastoma sensitivity to irradiation using patient-derived xenograft organoids across different models.
• Conducted short and long-term viability assays with glioblastoma patient-derived xenografts (PDXOs).
• Utilized X-ray irradiation at different doses (2 Gy and 4 Gy) in viability assays over 4 and 14 days.
• Performed morphological assessments and quantified cell viability with the CellTiter-Glo® assay.
• Monitored organoid integrity and size, focusing on structures ≥50 µm.
• The 4-day assay revealed generally low sensitivity to irradiation in all models tested.
• The 14-day assay distinguished between sensitive and resistant models, with up to 92% viability loss in sensitive organoids.
• Analysis showed that intrinsic tumor biology influenced irradiation responses rather than patient demographic factors.
• Models with EGFR amplification showed increased susceptibility to irradiation, while resistant models had enriched pathways related to metabolism and oxidative stress.