Dormant SOX9-positive cells facilitate MYC-driven recurrence of medulloblastoma
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE162080 | GEO | 2022/10/28
REPOSITORIES: GEO
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Project description:We undertook a comprehensive clinical and biological investigation of serial medulloblastoma biopsies obtained at diagnosis and relapse. Combined MYC gene family amplifications and P53 pathway defects commonly emerged at relapse, and all patients in this molecular group died of rapidly progressive disease post-relapse. To study this genetic interaction, we investigated a transgenic model of MYCN-driven medulloblastoma and found spontaneous development of Trp53 inactivating mutations. Abrogation of Trp53 function in this model produced aggressive tumors that mimicked the characteristics of relapsed human tumors with combined P53-MYC dysfunction. Restoration of p53 activity, genetic and therapeutic suppression of MYCN all reduced tumor growth and prolonged survival. Our findings identify P53–MYC interactions which emerge at medulloblastoma relapse as biomarkers of clinically aggressive disease that may be targeted therapeutically. Using this dataset, assignation of medulloblastoma molecular subgroup by Illumina 450k microarray was performed for diagnostic and relapsed medulloblastoma samples to compare subgroup membership at diagnosis and relapse. We investigated the DNA methylation profiles of 18 diagnostic and 22 relapsing samples (including 15 diagnostic / relapse pairs) using the Illumina 450k methylation microarray
2015-04-23 | E-GEOD-62618 | biostudies-arrayexpress
Project description:Dormant SOX9-positive cells facilitate MYC-driven recurrence of medulloblastoma
| PRJNA680708 | ENA
Project description:We undertook a comprehensive clinical and biological investigation of serial medulloblastoma biopsies obtained at diagnosis and relapse. Combined MYC gene family amplifications and P53 pathway defects commonly emerged at relapse, and all patients in this molecular group died of rapidly progressive disease post-relapse. To study this genetic interaction, we investigated a transgenic model of MYCN-driven medulloblastoma and found spontaneous development of Trp53 inactivating mutations. Abrogation of Trp53 function in this model produced aggressive tumors that mimicked the characteristics of relapsed human tumors with combined P53-MYC dysfunction. Restoration of p53 activity, genetic and therapeutic suppression of MYCN all reduced tumor growth and prolonged survival. Our findings identify P53–MYC interactions which emerge at medulloblastoma relapse as biomarkers of clinically aggressive disease that may be targeted therapeutically. Using this dataset, assignation of medulloblastoma molecular subgroup by Illumina 450k microarray was performed for diagnostic and relapsed medulloblastoma samples to compare subgroup membership at diagnosis and relapse.
2015-04-23 | GSE62618 | GEO
Project description:We undertook a comprehensive clinical and biological investigation of serial medulloblastoma biopsies obtained at diagnosis and relapse. Combined MYC gene family amplifications and P53 pathway defects commonly emerged at relapse, and all patients in this molecular group died of rapidly progressive disease post-relapse. To study this genetic interaction, we investigated a transgenic model of MYCN-driven medulloblastoma and found spontaneous development of Trp53 inactivating mutations. Abrogation of Trp53 function in this model produced aggressive tumors that mimicked the characteristics of relapsed human tumors with combined P53–MYC dysfunction. Restoration of p53 activity, genetic and therapeutic suppression of MYCN all reduced tumor growth and prolonged survival. Our findings identify P53–MYC interactions which emerge at medulloblastoma relapse as biomarkers of clinically aggressive disease that may be targeted therapeutically. There are currently no effective therapies for children with relapsed medulloblastoma. While clinical and biological features of the disease at diagnosis are increasingly well understood, biopsy is rarely performed at relapse and few biological data are available to guide more effective treatments. Here, we show that medulloblastomas develop altered biology at relapse which is predictive of disease course and cannot be detected at diagnosis. We have discovered the emergence of P53–MYC interactions at relapse, as biomarkers of clinically aggressive relapsed disease, which can be modelled and targeted therapeutically in genetically-engineered mice. These data provide clear precedent for the incorporation of biopsy at relapse into routine clinical practice, to direct palliative care and the development of improved treatment strategies. mouse model expression profiles from various mouse Medulloblastoma models MYCN/MYC overexpressing with/without p53 Mutations were compared to human MB expression profiles using Non-negative Matrix Factorization projection in order to sub-type the mouse models
2015-04-23 | E-GEOD-62625 | biostudies-arrayexpress
Project description:We undertook a comprehensive clinical and biological investigation of serial medulloblastoma biopsies obtained at diagnosis and relapse. Combined MYC gene family amplifications and P53 pathway defects commonly emerged at relapse, and all patients in this molecular group died of rapidly progressive disease post-relapse. To study this genetic interaction, we investigated a transgenic model of MYCN-driven medulloblastoma and found spontaneous development of Trp53 inactivating mutations. Abrogation of Trp53 function in this model produced aggressive tumors that mimicked the characteristics of relapsed human tumors with combined P53–MYC dysfunction. Restoration of p53 activity, genetic and therapeutic suppression of MYCN all reduced tumor growth and prolonged survival. Our findings identify P53–MYC interactions which emerge at medulloblastoma relapse as biomarkers of clinically aggressive disease that may be targeted therapeutically. There are currently no effective therapies for children with relapsed medulloblastoma. While clinical and biological features of the disease at diagnosis are increasingly well understood, biopsy is rarely performed at relapse and few biological data are available to guide more effective treatments. Here, we show that medulloblastomas develop altered biology at relapse which is predictive of disease course and cannot be detected at diagnosis. We have discovered the emergence of P53–MYC interactions at relapse, as biomarkers of clinically aggressive relapsed disease, which can be modelled and targeted therapeutically in genetically-engineered mice. These data provide clear precedent for the incorporation of biopsy at relapse into routine clinical practice, to direct palliative care and the development of improved treatment strategies.
2015-04-23 | GSE62625 | GEO
Project description:Astrocytes, a major glial cell type in the brain, play a critical role in supporting the progression of medulloblastoma (MB), the most common malignant pediatric brain tumor. By lineage tracing analyses and single cell RNA sequencing, we demonstrate that astrocytes are predominately derived from the transdifferentiation of tumor cells in relapsed MB (but not in primary MB), although MB cells are generally believed to be neuronal-lineage committed. Such transdifferentiation of MB cells relies on Sox9, a transcription factor critical for gliogenesis. Our studies further reveal that bone morphogenetic proteins (BMPs) stimulate the transdifferentiation of MB cells by inducing the phosphorylation of Sox9. Pharmaceutical inhibition of BMP signaling represses MB cell transdifferentiation into astrocytes, and suppresses tumor relapse. Our studies establish the distinct cellular sources of astrocytes in primary and relapsed MB, and provide an avenue to prevent and treat MB relapse by targeting tumor cell transdifferentiation.
2021-06-24 | GSE175416 | GEO
Project description:We describe an 8 year old child who had disseminated anaplastic medulloblastoma and a deleterious heterozygous BRCA2 6174delT germline mutation. Molecular profiling was consistent with Group 4 medulloblastoma. The posterior fossa mass was resected and the patient received intensive chemotherapy and craniospinal irradiation. Despite this, the patient succumbed to a second recurrence of his medulloblastoma, which presented eight months after diagnosis as malignant pleural and peritoneal effusions. Continuous medulloblastoma cell lines were isolated from the original tumor (CHLA-01-MED) and the malignant pleural effusion (CHLA-01R-MED). Here we provide their analyses, including in vitro and in vivo growth, drug sensitivity, comparative genomic hybridization and next generation sequencing analysis. In addition to the BRCA2 6174delT, the medulloblastoma cells had amplification of MYC, deletion at Xp11.2 and isochromosome 17, but no structural variations or overexpression of GFI1 or GFI1B. To our knowledge, this is the first pair of diagnosis/recurrence medulloblastoma cell lines, the only medulloblastoma cell lines with BRCA2 6174delT described to date, and the first reported case of a child with medulloblastoma associated with a germline BRCA2 6174delT who did not also have Fanconi anemia. Continuous medulloblastoma cell lines were isolated from the original tumor (CHLA-01-MED) and the malignant pleural effusion (CHLA-01R-MED). Here we provide their analyses, including in vitro and in vivo growth, drug sensitivity, comparative genomic hybridization with Agilent 400k CGH arrays and whole transcriptome RNASeq analysis.
2015-07-06 | E-GEOD-70003 | biostudies-arrayexpress
Project description:SOX9 is a master transcription factor that regulates development and stem cell programs. However, its potential oncogenic activity and regulatory mechanisms that control SOX9 protein stability are poorly understood. Here we show that SOX9 is a substrate of FBW7, a tumor suppressor and a SCF (Skp1-Cul1-F-box)-type ubiquitin ligase. FBW7 recognizes a conserved degron surrounding threonine 236 (T236) in SOX9 that is phosphorylated by GSK3 kinase. Specifically, FBW7-alpha targets T236-phosphorylated SOX9 for ubiquitylation and proteasomal degradation. Further, we demonstrate that FBW7 inactivation stabilizes SOX9 protein promoting migration, metastasis and treatment resistance in medulloblastoma, one of the most common childhood brain tumors. Notably, expression of mutationally stabilized SOX9-T236/240A in medulloblastoma cells coincides with activation of pro-metastatic genes. FBW7 is frequently downregulated in all medulloblastoma subgroups and mutated specifically in SHH-driven medulloblastoma. In cases where FBW7 mRNA levels are low, SOX9 protein is significantly elevated and this phenotype is associated with metastasis at diagnosis and poor patient outcome. Finally, pharmacological inhibition of PI3K/Akt/mTOR activity destabilizes SOX9 in a GSK3/FBW7-dependent manner, rendering medulloblastoma cells sensitive to cytostatic treatment.
2016-09-13 | GSE84320 | GEO
Project description:Medulloblastoma is the most common malignant pediatric brain tumor, and leptomeningeal dissemination (LMD) of medulloblastoma portends a poorer prognosis at diagnosis and is incurable at recurrence. The biological mechanisms underlying LMD in medulloblastoma are largely unclear. The Abelson (ABL) family of non-receptor tyrosine kinases has been implicated in cancer cell migration, invasion, adhesion, and chemotherapy resistance, and these kinases are upstream mediators of the oncogene c-MYC in fibroblasts. However, their role in medulloblastoma has not yet been explored. Therefore, the purpose of this work is to elucidate the role of the ABL kinases, ABL1 and ABL2, in medulloblastoma LMD. We show here that ABL1/2 mRNA is highly expressed in human medulloblastoma tumor samples and cell lines and that pharmacologic inhibition of ABL kinases results in medulloblastoma cell death. Knockdown of the ABL kinase genes ABL1 and ABL2 results in decreased adhesion to the extracellular matrix protein, vitronectin, and decreased medulloblastoma proliferation in a mouse model of medulloblastoma LMD (resulting in decreased tumor burden with subsequent increased overall survival. Further, both pharmacologic inhibition of ABL1/2 and ABL1/2 knockdown resulted in decreased c-myc expression, revealing a putative signaling pathway. In summary, this work highlights the potential role of ABL kinases in medulloblastoma LMD via c-myc expression.
2023-10-04 | GSE224691 | GEO
Project description:Aberrant oncogenic activation of MYC drives tumorigenesis in the most aggressive subset of medulloblastoma, the most common malignant brain tumor in childhood. Metastatic dissemination at diagnosis and at recurrence is commonly observed in MYC-driven medulloblastomas. Since these tumors display remarkable resistance to standard multimodal therapeutic approaches, epigenetic modulators commonly altered in these tumors are highly promising targets for novel therapeutic approaches. Here, we report on a cross-entity, high-throughput epigenetic drug screen to evaluate therapeutic vulnerabilities in the most common malignant primary brain tumors. Specifically, we performed a primary screen including 78 epigenetic inhibitors and a secondary screen including 20 histone deacetylase inhibitors (HDACi) to compare response profiles in atypical teratoid/rhabdoid tumor (AT/RT, n=11), medulloblastoma (n=14), and glioblastoma (n=14). This unbiased approach revealed preferential activity of HDACi in MYC-driven medulloblastoma. Importantly, the class I selective HDACi CI-994 showed significant cell viability reduction mediated by induction of apoptosis in MYC-driven medulloblastoma, with little to no activity in non-MYC-driven medulloblastoma, AT/RT, and glioblastoma in vitro. Notably, CI-994 displayed antitumoral effects at the primary site and the metastatic compartment in two orthotopic mouse models of MYC-driven medulloblastoma. Furthermore, synergistic drug screening and RNA sequencing revealed NFκB pathway induction as a mechanism of resistance to CI-994 treatment. Taken together, our findings identified MYC pathway activation as a predictive biomarker for epigenetic treatment intervention in high-risk medulloblastoma and provide a preclinical rationale for further exploration of CI-994 combined with NFκB pathway inhibitors in the treatment of MYC-driven medulloblastoma.
2019-12-13 | GSE123760 | GEO