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Göbel C, Schoof M, Holdhof D, Spohn M, Schüller U. SMARCA4 Loss and Mutated β-Catenin Induce Proliferative Lesions in the Murine Embryonic Cerebellum. J Neurosci 2024; 44:e1605232024. [PMID: 38383496 PMCID: PMC11007475 DOI: 10.1523/jneurosci.1605-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 02/23/2024] Open
Abstract
Almost all medulloblastomas (MB) of the Wingless/Int-1 (WNT) type are characterized by hotspot mutations in CTNNB1, and mouse models have convincingly demonstrated the tumor-initiating role of these mutations. Additional alterations in SMARCA4 are detected in ∼20% of WNT MB, but their functional role is mostly unknown. We, therefore, amended previously described brain lipid binding protein (Blbp)-cre::Ctnnb1(ex3)fl/wt mice by the introduction of floxed Smarca4 alleles. Unexpectedly, mutated and thereby stabilized β-catenin on its own induced severe developmental phenotypes in male and female Blbp-cre::Ctnnb1(ex3)fl/wt mice in our hands, including a thinned cerebral cortex, hydrocephalus, missing cerebellar layering, and cell accumulations in the brainstem and cerebellum. An additional loss of SMARCA4 even resulted in prenatal death for most mice. Respective Blbp-cre::Ctnnb1(ex3)fl/wt::Smarca4fl/rec mutants (male and female) developed large proliferative lesions in the cerebellum evolving from E13.5 to E16.5. Histological and molecular analysis of these lesions by DNA methylation profiling and single-cell RNA sequencing suggested an origin in early undifferentiated SOX2-positive cerebellar progenitors. Furthermore, upregulated WNT signaling, altered actin/cytoskeleton organization, and reduced neuronal differentiation were evident in mutant cells. In vitro, cells harboring alterations in both Ctnnb1 and Smarca4 were negatively selected and did not show tumorigenic potential after transplantation in adult female recipient mice. However, in cerebellar explant cultures, mutant cells displayed significantly increased proliferation, suggesting an important role of the embryonic microenvironment in the development of lesions. Altogether, these results represent an important first step toward the unraveling of tumorigenic mechanisms induced by aberrant WNT signaling and SMARCA4 deficiency.
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Affiliation(s)
- Carolin Göbel
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
| | - Melanie Schoof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
| | - Dörthe Holdhof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
| | - Michael Spohn
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
| | - Ulrich Schüller
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
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Göbel C, Godbole S, Schoof M, Holdhof D, Kresbach C, Loose C, Neumann J, Schüller U. MYC overexpression and SMARCA4 loss cooperate to drive medulloblastoma formation in mice. Acta Neuropathol Commun 2023; 11:174. [PMID: 37919824 PMCID: PMC10621315 DOI: 10.1186/s40478-023-01654-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/17/2023] [Indexed: 11/04/2023] Open
Abstract
Group 3 medulloblastoma is one of the most aggressive types of childhood brain tumors. Roughly 30% of cases carry genetic alterations in MYC, SMARCA4, or both genes combined. While overexpression of MYC has previously been shown to drive medulloblastoma formation in mice, the functional significance of SMARCA4 mutations and their suitability as a therapeutic target remain largely unclear. To address this issue, we combined overexpression of MYC with a loss of SMARCA4 in granule cell precursors. Both alterations did not increase proliferation of granule cell precursors in vitro. However, combined MYC overexpression and SMARCA4 loss successfully induced tumor formation in vivo after orthotopic transplantation in recipient mice. Resulting tumors displayed anaplastic histology and exclusively consisted of SMARCA4-negative cells although a mixture of recombined and non-recombined cells was injected. These observations provide first evidence for a tumor-promoting role of a SMARCA4 deficiency in the development of medulloblastoma. In comparing the transcriptome of tumors to the cells of origin and an established Sonic Hedgehog medulloblastoma model, we gathered first hints on deregulated gene expression that could be specifically involved in SMARCA4/MYC driven tumorigenesis. Finally, an integration of RNA sequencing and DNA methylation data of murine tumors with human samples revealed a high resemblance to human Group 3 medulloblastoma on the molecular level. Altogether, the development of SMARCA4-deficient medulloblastomas in mice paves the way to deciphering the role of frequently occurring SMARCA4 alterations in Group 3 medulloblastoma with the perspective to explore targeted therapeutic options.
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Affiliation(s)
- Carolin Göbel
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Shweta Godbole
- Center for Molecular Neurobiology, Falkenried 94, Hamburg, 20251, Germany
| | - Melanie Schoof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Dörthe Holdhof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Catena Kresbach
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
| | - Carolin Loose
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Julia Neumann
- Center for Molecular Neurobiology, Falkenried 94, Hamburg, 20251, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
| | - Ulrich Schüller
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany.
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany.
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany.
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Brugmans AK, Walter C, Moreno N, Göbel C, Holdhof D, de Faria FW, Hotfilder M, Jeising D, Frühwald MC, Skryabin BV, Rozhdestvensky TS, Wachsmuth L, Faber C, Dugas M, Varghese J, Schüller U, Albert TK, Kerl K. A Carboxy-terminal Smarcb1 Point Mutation Induces Hydrocephalus Formation and Affects AP-1 and Neuronal Signalling Pathways in Mice. Cell Mol Neurobiol 2023; 43:3511-3526. [PMID: 37219662 PMCID: PMC10477118 DOI: 10.1007/s10571-023-01361-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/08/2023] [Indexed: 05/24/2023]
Abstract
The BAF (BRG1/BRM-associated factor) chromatin remodelling complex is essential for the regulation of DNA accessibility and gene expression during neuronal differentiation. Mutations of its core subunit SMARCB1 result in a broad spectrum of pathologies, including aggressive rhabdoid tumours or neurodevelopmental disorders. Other mouse models have addressed the influence of a homo- or heterozygous loss of Smarcb1, yet the impact of specific non-truncating mutations remains poorly understood. Here, we have established a new mouse model for the carboxy-terminal Smarcb1 c.1148del point mutation, which leads to the synthesis of elongated SMARCB1 proteins. We have investigated its impact on brain development in mice using magnetic resonance imaging, histology, and single-cell RNA sequencing. During adolescence, Smarcb11148del/1148del mice demonstrated rather slow weight gain and frequently developed hydrocephalus including enlarged lateral ventricles. In embryonic and neonatal stages, mutant brains did not differ anatomically and histologically from wild-type controls. Single-cell RNA sequencing of brains from newborn mutant mice revealed that a complete brain including all cell types of a physiologic mouse brain is formed despite the SMARCB1 mutation. However, neuronal signalling appeared disturbed in newborn mice, since genes of the AP-1 transcription factor family and neurite outgrowth-related transcripts were downregulated. These findings support the important role of SMARCB1 in neurodevelopment and extend the knowledge of different Smarcb1 mutations and their associated phenotypes.
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Affiliation(s)
- Aliska K Brugmans
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany
| | - Carolin Walter
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany
- Institute of Medical Informatics, University of Münster, 48149, Münster, Germany
| | - Natalia Moreno
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany
| | - Carolin Göbel
- Department of Paediatric Haematology and Oncology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
- Research Institute Children's Cancer Center, 20251, Hamburg, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Dörthe Holdhof
- Department of Paediatric Haematology and Oncology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
- Research Institute Children's Cancer Center, 20251, Hamburg, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Flavia W de Faria
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany
| | - Marc Hotfilder
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany
| | - Daniela Jeising
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany
| | - Michael C Frühwald
- Swabian Children's Cancer Center, Paediatrics and Adolescent Medicine, University Medical Center Augsburg, 86156, Augsburg, Germany
| | - Boris V Skryabin
- Medical Faculty, Core Facility TRAnsgenic Animal and Genetic Engineering Models (TRAM), University of Münster, 48149, Münster, Germany
| | - Timofey S Rozhdestvensky
- Medical Faculty, Core Facility TRAnsgenic Animal and Genetic Engineering Models (TRAM), University of Münster, 48149, Münster, Germany
| | - Lydia Wachsmuth
- Clinic of Radiology, Translational Research Imaging Center (TRIC), University of Münster, 48149, Münster, Germany
| | - Cornelius Faber
- Clinic of Radiology, Translational Research Imaging Center (TRIC), University of Münster, 48149, Münster, Germany
| | - Martin Dugas
- Institute of Medical Informatics, University of Münster, 48149, Münster, Germany
- Institute of Medical Informatics, Heidelberg University Hospital, 69120, Heidelberg, Germany
| | - Julian Varghese
- Institute of Medical Informatics, University of Münster, 48149, Münster, Germany
| | - Ulrich Schüller
- Department of Paediatric Haematology and Oncology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
- Research Institute Children's Cancer Center, 20251, Hamburg, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Thomas K Albert
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany
| | - Kornelius Kerl
- Department of Paediatric Haematology and Oncology, University Children's Hospital Münster, 48149, Münster, Germany.
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Holdhof D, On JH, Schoof M, Göbel C, Schüller U. Simultaneous Brg1 Knockout and MYCN Overexpression in Cerebellar Granule Neuron Precursors Is Insufficient to Drive Tumor Formation but Temporarily Enhances their Proliferation and Delays their Migration. Cerebellum 2021; 20:410-419. [PMID: 33387268 PMCID: PMC8213679 DOI: 10.1007/s12311-020-01219-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 11/12/2020] [Indexed: 11/29/2022]
Abstract
Medulloblastoma (MB) is the most common malignant brain tumor in childhood. According to the World Health Organization (WHO) classification of central nervous system (CNS) tumors, this embryonal tumor is divided into a wingless (WNT)-activated, Sonic hedgehog (SHH)-activated, and non-WNT/non-SHH entity. The latter is poorly defined but frequently carries mutations in Brahma-related gene 1 (BRG1) or amplifications of MYCN. Here, we investigated whether a combination of a Brg1 knockout and an overexpression of MYCN in cerebellar granule neuron precursors or multipotent neural stem cells is sufficient to drive brain tumor formation in mice. To this end, we generated Math1-creERT2::Brg1fl/fl::lslMYCN and hGFAP-cre::Brg1fl/fl::lslMYCN mice, respectively. We did not observe brain tumor formation in any of these models. hGFAP-cre::Brg1fl/fl::lslMYCN mice revealed severe CNS abnormalities with short survival, similar to the situation with a sole loss of Brg1, as we previously described. Investigation of Math1-creERT2::Brg1fl/fl::lslMYCN mice with a tamoxifen induction at postnatal day 3 revealed a regular survival but significant increase in cerebellar granule neuron precursor proliferation, followed by a delayed inward migration of these cells. This is in stark contrast to the hypoplastic cerebellum that we previously observed after embryonic deletion of Brg1 in Math1 positive cerebellar granule neurons. Our results indicate a time-specific function of Brg1 in cerebellar granule neuron precursors. Yet, the exact temporal and spatial origin of non-WNT/non-SHH MB remains unclear.
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Affiliation(s)
- Dörthe Holdhof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, N63 (HPI), D-20251, Hamburg, Germany
| | - Ji Hoon On
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, N63 (HPI), D-20251, Hamburg, Germany
| | - Melanie Schoof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, N63 (HPI), D-20251, Hamburg, Germany
| | - Carolin Göbel
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, N63 (HPI), D-20251, Hamburg, Germany
| | - Ulrich Schüller
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, N63 (HPI), D-20251, Hamburg, Germany.
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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