A Set of Cell Lines Derived from a Genetic Murine Glioblastoma Model Recapitulates Molecular and Morphological Characteristics of Human Tumors.

Barbara Costa,Martin Löwer,Andrey Korshunov,Heike Peterziel,Lukas Bunse,Peter Angel,Tanja Eisemann,Pavle Boskovic,Melania Cusimano,Ekaterina L Ivanova,Sabrina Lohr,Michael N C Fletcher,Stefanie Burchard,Bernhard Radlwimmer,Michael Platten,Luigi Naldini,Nadia Coltella,Hai-Kun Liu

doi:10.3390/cancers13020230

Abstract

Simple SummaryGlioblastoma (GBM) is a highly aggressive and almost inevitably lethal brain tumor. Animal models for GBM are crucial to study how the tumor evolves in vivo and to test novel treatment options. Most currently available models are based on the transplantation of human GBM cells into mice with a defective immune system. However, this approach does not allow to study the contribution of immune cells to GBM growth and to test immunotherapies. Transplantation of murine GBM cells overcomes this limitation, however, up to now, only a limited number, which mostly do not mimic important characteristics of human GBM, have been available. Via in vivo passaging, we established a set of murine GBM cell lines that (i) can be easily cultivated and further genetically manipulated, (ii) upon transplantation develop tumors with phenotypic and pathological features of human GBM, and (iii) are available to be shared with the scientific community.Glioblastomas (GBM) are the most aggressive tumors affecting the central nervous system in adults, causing death within, on average, 15 months after diagnosis. Immunocompetent in-vivo models that closely mirror human GBM are urgently needed for deciphering glioma biology and for the development of effective treatment options. The murine GBM cell lines currently available for engraftment in immunocompetent mice are not only exiguous but also inadequate in representing prominent characteristics of human GBM such as infiltrative behavior, necrotic areas, and pronounced tumor heterogeneity. Therefore, we generated a set of glioblastoma cell lines by repeated in vivo passaging of cells isolated from a neural stem cell-specific Pten/p53 double-knockout genetic mouse brain tumor model. Transcriptome and genome analyses of the cell lines revealed molecular heterogeneity comparable to that observed in human glioblastoma. Upon orthotopic transplantation into syngeneic hosts, they formed high-grade gliomas that faithfully recapitulated the histopathological features, invasiveness and immune cell infiltration characteristic of human glioblastoma. These features make our cell lines unique and useful tools to study multiple aspects of glioblastoma pathomechanism and to test novel treatments in an intact immune microenvironment.

Highlights

Glioblastomas are the most prevalent malignant brain tumors in adults
Clustering of the cell lines using these genes recapitulated the multidimensional scaling analysis (MDS) analysis on all genes (Figure 2A), with the ctrlNSCs and early passage samples grouping together and later passages forming distinct clusters based on their lineage. These results show that the neural stem-cells-derived glioblastoma cell lines serially passaged in vivo reflect, at the transcriptomic level, the heterogeneity observed in human glioblastoma
The subventricular zone (SVZ) of the adult human brain contains a population of neural stem cells (NSCs), which are capable of multilineage differentiation [27,28]

Summary

Introduction

Glioblastomas are the most prevalent malignant brain tumors in adults. These WorldHealth Organization (WHO) grade IV tumors are defined by histopathologic features comprising mitotic figures, microvascular proliferation, necrosis, and extensive infiltration of the brain parenchyma, with the latter impairing complete surgical removal and almost inevitably leading to tumor relapse. Glioblastomas are the most prevalent malignant brain tumors in adults. Our knowledge of glioblastoma molecular pathomechanisms has greatly advanced in the past decade, and it has become widely accepted that IDH wildtype (IDHwt ) glioblastomas can be sub-classified into three subtypes: classical, proneural, and mesenchymal [3]. The corresponding subtype-specific RNA-expression-based signatures are influenced by the composition of the tumor microenvironment, including stromal and immune cell populations [4]. Despite these advances, we are still lacking in-vivo preclinical models that reflect the molecular and phenotypic heterogeneity of glioblastoma and recapitulate their complex interaction with the immune cells of the tumor microenvironment. In order to thoroughly understand the biology underlying glioblastoma development and to allow more predictive preclinical testing of new therapies, those glioblastoma animal models are urgently needed

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