• Login
• Admin

Porter, Harry (2025) Targeting tumour-astrocyte crosstalk for rational identification of novel therapeutic targets for atypical Teratoid/ Rhabdoid tumours. PhD thesis, University of Nottingham.

PDF (Corrections) (Thesis - as examined) - Repository staff only until 1 July 2027. Subsequently available to Anyone - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader Available under Licence Creative Commons Attribution. Download (11MB)

Abstract

Atypical Teratoid / Rhabdoid Tumours (AT/RTs) are rare and highly aggressive paediatric brain tumours. AT/RTs frequently arise in the cerebellum but also

develop in the supratentorial compartment and spine. They are classified as an embryonal brain tumour by the World Health Organisation (WHO). The majority of AT/RT arise in children under three years of age who experience severe side effects resulting from conventional anti-cancer therapies. Therefore, new non-cytotoxic biologically targeted treatments are urgently required to treat patients with AT/RT to minimise acute and long-term side effects including neurocognitive damage.

This work aims to identify mechanisms by which AT/RT cells may hijack interactions with the native non-disease brain microenvironment to promote tumour growth, focusing on the role of astrocytes, a specialised brain cell which maintains brain tissue homeostasis and health, and supports neuronal functioning. We develop a bespoke 3D in vitro model of AT/RT interaction with astrocytes and the native brain extracellular matrix (ECM). Decellularized cerebellar ECM was generated from healthy human autopsy brain tissue and added to a biologically inert poly(ethylene glycol) diacrylate hydrogel to form cerebellar ECM hydrogels (PEGDA-cECM). Patient-derived AT/RT cell lines were then co-cultured with primary human cerebellar astrocytes (HA-c) as 3D spheroids within the PEGDA-cECM over a period of 7 days before recovery of component cell types by fluorescence activated cell sorting.

Characterisation of the PEGDA-cECM hydrogel, in which AT/RT-astrocyte crosstalk was modelled, showed that the hydrogel retained core brain ECM components including hyaluronic acid and laminin. Furthermore, PEGDAcECM hydrogels were shown to be cyto-compatible with AT/RT and astrocyte cells in vitro and could be reproducibly generated. RNA-sequencing was conducted on AT/RT cell lines co-cultured with HA-c within the model. Compared to monoculture controls, AT/RT cell lines upregulated genes associated with neurodevelopment, proliferation, and migration in the presence of astrocytes. Furthermore, several genes which are upregulated in recurrent AT/RT were induced by the presence of astrocytes. These included the gene GAP43, a marker of tumour microtubes, which has been reported to mediate intercellular mitochondria transfer from astrocytes to glioblastoma cells. Using fluorescence microscopy, we showed that AT/RT cells form morphologically similar cell-cell processes with astrocytes. Furthermore, astrocytes were shown to transfer the mitochondria specific dye MitoTracker™ to AT/RT cells when co-cultured in 2D conditions.

Finally, drug compounds which may inhibit AT/RT-astrocyte crosstalk were identified for repurposing based on RNA-seq data and an initial screen conducted in AT/RT monocultures to assess their ability to inhibit AT/RT cell viability. We identified the mTOR inhibitor AZD8055 as potently inhibiting AT/RT cell viability and predict that it may act to block AT/RT-astrocyte crosstalk. Future ongoing work will assess the efficacy of AZD8055 in an AT/RT orthotopic xenograft model and aim to investigate the impact of

AZD8055 on AT/RT cells in the presence of astrocytes. This represents the identification of a rationally selected targeted therapy against AT/RT which may act to inhibit pro-survival signalling from astrocytes to AT/RT which could act to address the current clinical need for improved therapeutic options for patients.

Item Type:	Thesis (University of Nottingham only) (PhD)
Supervisors:	Rahman, Ruman Grundy, Richard McCrorie, Phoebe
Keywords:	AT/RT; Tumour Microenvironment; RNA-seq
Subjects:	W Medicine and related subjects (NLM Classification) > WL Nervous system
Faculties/Schools:	UK Campuses > Faculty of Medicine and Health Sciences > School of Medicine
Item ID:	81164
Depositing User:	Porter, Harry
Date Deposited:	23 Jul 2025 04:40
Last Modified:	23 Jul 2025 04:40
URI:	https://eprints.nottingham.ac.uk/id/eprint/81164

Actions (Archive Staff Only)

Edit View