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Updated: May 1, 2026

A Static Self-Directed Method for Generating Brain Organoids from Human Embryonic Stem Cells
Published on: March 4, 2020
Relative biological effectiveness and neural stem cell fate in carbon ion-irradiated human brain organoids
Tamara Bender1, Marco Durante2, Insa S Schroeder1
1GSI Helmholtzzentrum für Schwerionenforschung, Biophysics Department, Darmstadt, Germany.
Background And Purpose:
Heavy ion therapy offers a promising approach for treating brain tumors due to the high precision of ion beams and biological effectiveness. However, the mechanisms underlying contrast-enhanced brain lesions, which occur more frequently after ions than conventional X-rays, remain to be elucidated.
Materials And Methods:
Cerebral organoids were generated from human embryonic stem cells and exposed to high-energy carbon-ions at early (day 20) and late (day 80) developmental stages. Analyses of gene expression were performed using RT-PCR analysis, and protein expression was assessed using immunofluorescence staining.
Results:
We demonstrate that exposure to high-energy carbon (C)-ions induces the formation of ectopic choroid plexus (CP)-like structures in human cerebral organoids. RT-PCR analyses revealed that C-ion exposure alters the differentiation trajectories of neuroepithelial stem cells, driven by dysregulation of key developmental signaling pathways including NOTCH, WNT, and BMP. Moreover, we observed increased expression of CP-associated markers AQP1 and CLDN3. The relative biological effectiveness (RBE) of C-ions for the formation of fluid-filled cavities associated with CP-like tissue was calculated as 2.0 after both 60 and 100 days of differentiation.
Conclusion:
Our findings indicate that aberrant CP development is a central mechanism underlying post-radiation contrast-enhanced brain lesions, and that an RBE of 2 should be considered when determining dose thresholds for normal tissue tolerance in carbon ion therapy for brain tumors.

