Ex-vivo models of post-surgical residual disease in human glioblastoma

Abstract

Background Glioblastoma is a highly infiltrative, currently incurable brain cancer. To date, translation of novel therapies for glioblastoma from the laboratory into clinical trials has relied heavily on in vitro cell culture and murine (subcutaneous and orthotopic) xenograft models using cells derived from the main bulk of patient tumours. However, it is the residual cells left-behind after surgery that are responsible for disease progression and death in the clinic. A lack of substantial improvements in patient survival for decades suggests commonly used murine xenograft models, a key step before clinical trials, do not reflect the biology of residual disease in patients. Methods To address this, we have developed the ‘Sheffield Protocol’ to generate ex vivo models that reflect both resected, and post-surgical residual disease from the same patient. The protocol leverages parallel derivation of inherently treatment-resistant glioblastoma stem cells (GSCs) from ‘core’ and distant ‘edge’ regions through careful macrodissection of a large en bloc specimen, such as from a partial lobectomy for tumour, followed by tissue dissociation and propagation in serum-free media. Opportunistic en bloc specimen use can liberate the most distant infiltrative cells feasibly accessible from living patients. Results We provide an example illustrating that resected and residual disease models represent spatially divergent tumour subpopulations harbouring distinct transcriptomic and cancer stem cell marker expression profiles. We also introduce the ‘Sheffield Living Biobank’ of glioma models (SLB) that incorporates over 150 GSC lines from 60+ patients, including 44+ resected and residual models, which are available for academic use via MTA. Conclusions These models provide a novel tool to reduce animal xenograft usage by improving candidate drug triage in early preclinical studies and directly replacing animal studies for some therapies that are post-Phase 1+ clinical trial for other cancers/conditions to, ultimately, deliver more effective treatments for post-surgical residual disease in glioblastoma.