TMOD-26. ESTABLISHING A PATIENT-DERIVED, IN-VITRO ORGANOTYPIC SLICE CULTURE MODEL OF GBM

Glioblastoma Multiforme (GBM) is the most common primary malignant brain tumour. This tumour is universally fatal with a median survival of 15 months. Driving this pathology is an extremely heterogeneic tumour and complex tumour microenvironment. GBM research is primarily conducted using immortalized or primary cell lines due to their practicality and reproducibility. However, these cell lines do not effectively recapitulate the tumour microenvironment. Mouse models address these shortcomings but are laborious and expensive. We propose to utilize a patient derived organotypic culture model of GBM as an intermediary. We have utilized this model to test genetic manipulation via lentiviral transduction and the feasibility of utilizing this model to understand patient derived extracellular vesicles (EVs). We have sectioned and cultured patient derived organotypic models for 14 days without loss of viability. To determine if these organotypic cultures are amenable to lentiviral manipulation, tissue sections were transduced with far-red fluorescent lentivirus and efficiency determined by confocal laser scanning microscopy (CLSM) and flow cytometry (FC). To determine feasibility as a model for EVs, media obtained from patient-derived organotypic cultures was analyzed by western blot, nanoparticle tracking analysis (NTA), and nanoFlow Cytometry (nFC). In the future these EVs will be compared to those found in patient serum. The model of GBM has been lentivirally transduced to express a far-red fluorescent vector in approximately 15% of the slice, quantified by CLSM and FC. EV-sized particles positive for canonical EV markers have been identified in the media by NTA, nFC and western blot. Using lentiviral-mediated genetic engineering and emerging EV science, this organotypic slice culture models yields exciting utility in GBM research. The established organotypic slice culture model will likely be a valuable tool in the study of GBM biology and EV dynamics.