PRECLINICAL MODELS (Theme-2). Development of more accurate genetically engineered mouse models (GEMMs), and patient-derived orthotopic xenografts models (PDOXs), as well as 3D Systems (neurosphere, organoids and bioprinting) should contribute to a better understanding of brain tumour mechanisms.
This Action also aims to explore the use of advanced 4D intravital microscopy methods to study the response of brain cancer cells in GEMMs and PDOXs to innovative therapies at the singlecell level in their native environment. The CRISPR/Cas9 technology will be applied both in vitro and in vivo, to model the most frequent genetic alterations (e.g., EGFR, TP53, APOBEC) and to study their contribution to treatment response. In addition, high-throughput miRNA functional screening can be performed by using CRISPR/Cas9 libraries to identify miRNAs as possible sensitizers to standard therapy. Moreover, by combining optical access to the brain tumour using a cranial imaging window and multiphoton microscopy, the cellular response and resistance to therapy can be followed through the window over multiple days to weeks inside the living animal. This information can be correlated to histology including image analysis and is critical to identifying mechanisms of resistance in vivo.
Spatial transcriptomics will be carried out to investigate cell-to-cell variation within and between individual tumours. For ex vivo primary cell cultures, Net4BRAIN aims to develop and exploit advanced 3D cerebral organoids49 and bioprinting-based brain tumour models50 with a focus on meningioma. These will be used in studying vulnerabilities and drug resistance that including in vitro blood-brain tumour barrier (BBTB) models to better understand chemoresistance. Moreover, it will be essential to improve the formulation of ex vivo brain tumour propagation which currently does not reflect tumour heterogeneity.