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Stover, M.

Publications and source records attributed to Stover, M..

2 recordsLinked to original sources

Modelling Glioma Stem Cell-mediated Tumorigenesis Using Zebrafish PDX Systems

Glioblastoma is an aggressive brain tumour associated with high post-therapy recurrence and very poor survival rates. One of the factors contributing to the aggressive nature of this disease is the level of heterogeneity seen at the phenotypic and genetic level. Glioma Stem Cells (GSCs) are stem-like cells within the tumour with the ability to self-renew and give rise to different types of cells within the tumour, hence giving rise to the heterogeneity found in glioblastoma. GSCs are often implicated in the resistance of glioma to standard of care radiation and chemotherapy. The physical niche within a tumour mass supports stemness and aggressive characteristics of GSCs, hence, experimental systems providing a relevant tumour microenvironment are critical for adequate assessment of molecular mechanisms regulating GSC populations. Although, mouse models are a staple of an in vivo experimental design, they are neither time-nor cost-efficient. Danio rerio (zebrafish) patient-derived xenografts (PDXs) overcome several of the obstacles of the mammalian systems. Zebrafish constitute a high throughput, easily reproducible experimental platform allowing for life relevant investigation into the aggressiveness of GSC populations. This chapter describes methods required for generation of zebrafish PDXs to study aspects of GSC-mediated tumorigenesis and interactions with the tumour microenvironment. Consistency between labs for these experiments is required to move the discovery of effective treatments for glioblastoma moving forward.

cancer biology↗

Pharmacokinetics and biodistribution of extracellular vesicles administered intravenously and intranasally to Macaca nemestrina

Extracellular vesicles (EVs) have great potential as novel drug carriers for the treatment of various diseases. These lipid bilayer vesicles are naturally abundant in mammalian tissues and circulation, can be loaded with therapeutic small molecule drugs, (si)RNA, proteins and CRISPR/Cas9, and may be engineered for retention by specific tissues. However, many questions remain on the optimal dosing, administration route, and pharmacokinetics of EVs. Previous studies have addressed biodistribution and pharmacokinetics in rodents, but little evidence is available from larger animals. Here, we investigated the pharmacokinetics and biodistribution of Expi293F-derived EVs labelled with a highly sensitive nanoluciferase reporter (palmGRET) in a non-human primate model (Macaca nemestrina), comparing intravenous (IV) and intranasal (IN) administration over a 125-fold dose range. We report that EVs administered IV had markedly longer circulation times in plasma than previously reported in mice, and were detectable in cerebrospinal fluid (CSF) after 30-60 minutes. Already after one minute following IV administration, we observed EV uptake by PBMCs, most notably B-cells. EVs were detected in liver and spleen within one hour of IV administration. None of the IN doses resulted in readily detectable EV levels in plasma, CSF, or organs, suggesting that IN delivery of EVs in large animals including humans may require reconsideration or pretreatment approaches. Furthermore, EV circulation times strongly decreased after repeated IV administration, possibly due to immune responses and with clear implications for xenogeneic EV-based therapeutics. We hope that our findings from this baseline study in macaques will help to inform future research and therapeutic development of EVs.

pharmacology and toxicology↗