BIOL-11. PRECLINICAL MODELLING OF PEDIATRIC BRAIN TUMORS USING ORGANOID TECHNOLOGY

Molecular characterization has resulted in improved classification of pediatric brain tumors, leading to many novel (sub)types with distinct oncodriving events. To study tumor biology and to perform translational research on each of these tumors, preclinical models are essential. However, we are currently lacking sufficient models, especially in vitro, to represent each (sub)type and their heterogeneity.To generate large series of preclinical in vitro models for pediatric brain tumors, we are using organoid technology. Cells from patient samples and patient-derived xenograft samples have been taken into culture to establish 3D organoids using tumor type specific culture conditions. These organoid lines retain the molecular characteristics of the original tumor tissue. They can be used to perform high-throughput drug screens, genetic manipulations, and co-cultures with, for instance, immune cells.Viable tissue is not always available for all tumor (sub)types and specific oncodrivers. To circumvent this lack of tissue, we can also induce tumors in vitro. Therefore, we generate cerebral and cerebellar brain organoids from human pluripotent stem cells. These organoids mimic human developing brain cells and can be genetically manipulated to model different brain tumor types. These genetically engineered brain tumor models allow us to study the cellular origins of pediatric brain tumors and the different tumor driving mechanisms. Tumors induced in the brain organoids histologically and molecularly resemble human patient samples based on (single cell) transcriptomic analyses. Moreover, the tumor cells are able to establish xenografts in mouse brains.In summary, organoid technology provides a novel avenue to establish in vitro models for pediatric brain tumors. At the meeting we will present data for various new ependymoma, medulloblastoma and embryonal brain tumor organoid models.