Modeling glioblastoma invasion using human brain organoids and single-cell transcriptomics

Abstract

Background Glioblastoma (GBM) consists of devastating neoplasms with high invasive capacity, which have been difficult to study in vitro in a human-derived model system. Therapeutic progress is also limited by cellular heterogeneity within and between tumors, among other factors such as therapy resistance. To address these challenges, we present an experimental model using human cerebral organoids as a scaffold for patient-derived GBM cell invasion. Methods This study combined tissue clearing and confocal microscopy with single-cell RNA sequencing of GBM cells before and after co-culture with organoid cells. Results We show that tumor cells within organoids extend a network of long microtubes, recapitulating the in vivo behavior of GBM. Transcriptional changes implicated in the invasion process are coherent across patient samples, indicating that GBM cells reactively upregulate genes required for their dispersion. Potential interactions between GBM and organoid cells identified by an in silico receptor–ligand pairing screen suggest functional therapeutic targets. Conclusions Taken together, our model has proven useful for studying GBM invasion and transcriptional heterogeneity in vitro, with applications for both pharmacological screens and patient-specific treatment selection on a time scale amenable to clinical practice. Key Points 1. Organoid technology and single-cell transcriptomics reveal cellular interactions of invasive GBM cells. 2. Transcriptional changes implicated during invasion suggest novel therapeutic targets for GBM. 3. Time scales are amenable to clinical practice and high-content drug screens.

Glioblastoma Organoids: Pre-Clinical Applications and Challenges in the Context of Immunotherapy

“…The authors showed that GSCs were able to invade and proliferate within the healthy brain organoid and to form interconnecting microtubes. Another study confirmed that GSCs transcriptionally adapted to mini-brain microenvironment in line with their in vivo behavior (87). Although Linkous et al showed similar invasion of GSCs in cerebral organoids of different age, others reported GBM cell invasion only in early stage cerebral organoids, whereas invasion into fully mature organoids was halted (88).…”

“…Similar cocultures of human cerebral organoids could be applied to patientderived GBM organoids in the future. Of note, the protocol is tedious, as efficient GBM invasion inside the cerebral organoid often requires removal of the ECM embedding (87,88). If ECM is preserved, GBM cells primarily adhere to the matrix and grow on top of the surface.…”

Advances in 3D neuronal microphysiological systems: towards a functional nervous system on a chip

“… 2019 ; Krieger et al . 2020 ). Such cancer-bearing organoids promise personalized medicine by exploring most effective therapeutics for a given patient as well as the development of novel therapeutics (Plummer et al .…”

Cerebral organoids: emerging ex vivo humanoid models of glioblastoma

“…The second relies on the introduction of patient derived GSCs into organoids, which is particularly well suited for understanding clinical characteristics following initial tumor formation. Due to the central role of GSCs as the cell type that drives tumor progression and recurrence [33], these efforts have focused on introducing GSCs into COs, either as single cells [34][35][36][37] or as GSC spheres [38]. Characteristic results of the latter method, which is utilized in our laboratory, are presented in Fig.…”

“…Given the differences in human and mouse brain structures [40], this co-culture system was not further used aside from being a proof-of-principle for future improvements. Subsequently, several other groups utilized the fusion approach as an ex vivo model of GBM [32,[34][35][36][37] and drug screening [31,36].…”