Glioblastoma Tissue Slice Tandem-Cultures for Quantitative Evaluation of Inhibitory Effects on Invasion and Growth

Abstract

Glioblastomas (GBMs) are the most malignant brain tumors and are essentially incurable even after extensive surgery, radiotherapy, and chemotherapy, mainly because of extensive infiltration of tumor cells into the adjacent normal tissue. Thus, the evaluation of novel drugs in malignant glioma treatment requires sophisticated ex vivo models that approach the authentic interplay between tumor and host environment while avoiding extensive in vivo studies in animals. This paper describes the standardized setup of an organotypic brain tissue slice tandem-culture system, comprising of normal brain tissue from adult mice and tumor tissue from human glioblastoma xenografts, and explore its utility for assessing inhibitory effects of test drugs. The microscopic analysis of vertical sections of the slice tandem-cultures allows for the simultaneous assessment of (i) the invasive potential of single cells or cell aggregates and (ii) the space occupying growth of the bulk tumor mass, both contributing to malignant tumor progression. The comparison of tissue slice co-cultures with spheroids vs. tissue slice tandem-cultures using tumor xenograft slices demonstrates advantages of the xenograft tandem approach. The direct and facile application of test drugs is shown to exert inhibitory effects on bulk tumor growth and/or tumor cell invasion, and allows their precise quantitation. In conclusion, we describe a straightforward ex vivo system mimicking the in vivo situation of the tumor mass and the normal brain in GBM patients. It reduces animal studies and allows for the direct and reproducible application of test drugs and the precise quantitation of their effects on the bulk tumor mass and on the tumor’s invasive properties.

Combining organotypic tissue culture with multi-color fluorescence light-sheet microscopy (OTCxLSFM) – a novel tool to study glioma invasion/migration

“…Many approaches exist to tackle this complexity, both with their own advantages and disadvantages (reviewed in (Souberan and Tchoghandjian 2020)) and we present the next-level development of OTCs. The concept to study GBM growth using brain slices has been applied in multiple studies (de Bouard et al 2007;Parker et al 2017;Parker et al 2018) mainly employing post-natal brain slices derived from mice, but also from rats grown under high-serum species-unmatched serum-supplementation (Ren et al 2015;Ghoochani et al 2016;Sidorcenco et al 2020), mainly focusing on tumor growth. Some reports show applicability towards analysis on angiogenesis and tumor microenvironment however, these studies mainly rely on further sectioning the slices thereby further increasing the workload.…”

Combining organotypic tissue culture with light‐sheet microscopy (OTCxLSFM) to study glioma invasion

“…Similarly, by harnessing the acquisition speed of LSFM, intrinsic heterogeneity can be accounted for. The concept of studying GBM growth using brain slices has been applied in multiple studies (de Bouard et al, 2007;Parker et al, 2017Parker et al, , 2018 mainly employing post-natal brain slices derived not only from mice but also from rats grown under high-serum, species-unmatched serum supplementation (Ren et al, 2015;Ghoochani et al, 2016;Sidorcenco et al, 2020), mainly focusing on tumor growth. Some reports show applicability toward analysis of angiogenesis and tumor microenvironment.…”

Glioblastoma and the search for non-hypothesis driven combination therapeutics in academia

“…Recapitulating all aspects of the brain microenvironment is difficult in vitro . Therefore, ex vivo brain slice assays are used to maintain the complexities of the extracellular matrix and brain architecture and preserve in vivo morphology on which to grow tumour cells or spheroids and monitor cell behaviour in response to treatment ( 208 – 210 ). It has been shown that GBM stem cell motility decreases compared to 2D culture when maintained in this way, presumably due to additional barriers such as the extracellular matrix and the need for extracellular matrix remodelling ( 211 ).…”