HG-83
STABILITY OF PATIENT-DERIVED IN VITRO CULTURES OF STEM-LIKE CELLS FROM HIGH-GRADE PAEDIATRIC BRAIN TUMOURS Free

Glioblastoma multiforme (GBM) is the most frequent and most aggressive malignant primary brain tumour in adults. The understanding of the molecular biology that underlies adult glioblastoma has been extended over many years due to large-scale genomic and epigenomic profiling and the availability of relevant in vitro models for functional analyses. High-grade gliomas in children and adolescents have remained a relatively under-investigated disease but the latest genomic and epigenomic profiling studies have provided insight into the biology underlying these tumours in children which have also pointed to large differences compared to the tumours found in adults. In vitro-cultured primary tumour cells from patients are indispensable tools for functional analyses and development of new therapies. However, relevant well-characterised in vitro cultures from paediatric gliomas have been lacking. We have therefore established patient-derived in vitro cultures and performed thorough characterization of the cells using large-scale analyses of DNA methylation, copy-number alterations and investigated their stability during prolonged time in culture. We show that the cells retain the chromosomal, mutational and DNA methylation profiles found in the tumour samples from which they were generated. In addition, the cells were positive for stem cell markers such as nestin, SOX2 and vimentin and respond to differentiation cues. We demonstrate that the cells are suitable for drug screening experiments. The cells can thus be used as a relevant and robust model system for studying paediatric brain tumours.