Project description:RNA-sequencing of H3.3-G34R and H3.3-WT HGG cells was performed to uncover transcriptomic differences related to the presence of H3.3-G34R mutation in a pediatric high grade glioma model, using a Sleeping beauty derived genetically engenieered mouse model.
Project description:Epigenetic dysregulation is a universal feature of cancer that results in altered patterns of gene expression that drive malignancy. Brain tumors exhibit subtype-specific epigenetic alterations, however the molecular mechanisms responsible for these diverse epigenetic states remain unclear. Here we show that the developmental transcription factor Sox9 differentially regulates epigenomic states in high-grade glioma (HGG) and ependymoma (EPN). These contrasting roles for Sox9 correspond with protein interactions with histone deacetylating complexes in HGG, and association with the Rela oncofusion in EPN. Together, our studies demonstrate how epigenomic states are differentially regulated in distinct subtypes of brain tumors, while revealing divergent roles for Sox9 in HGG and EPN tumorigenesis.
Project description:Glioma study (gene expression and CGH): Brain tumours are the most common solid tumors in children and have the highest mortality rate of all solid pediatric tumours. Despite advances in multimodality therapy, children with high-grade gliomas invariably have an Overall Survival (OS) around 20% at 5 years. There is growing evidence that the biological knowledge and the histo-prognostic classifications used for the management of adult HGG may not fully apply to children. Interobserver variability and specificity of pediatric tumors with respect to the World Health Organization (WHO) classification have lead to a high rate of misclassification in multi-institutional studies. From 90 biopsies of children with HGG (High Grade Glioma), comprising 37 DIPG (Diffuse Infiltrating Pontine Glioma), 73 extracted RNA have been hybrized on Agilent 4x44K GE arrays and 71 extracted DNA have been hybrized on Agilent 44K and 4x44K CGH arrays. The dataset contains raw data files from Feature Extraction. Genomic data were jointly analysed with clinical and histological data comprising: date_of_diagnosis, date_of_last_news, WHO_grade, deceased_at_median_survival_time, deceased_at_2years, localization of the tumour in brain, gadolinium_T1_inf_T2. A specific analysis was performed on DIPG.
Project description:Neuronal activity promotes high-grade glioma (HGG) growth. An important mechanism mediating this neural regulation of brain cancer is activity-dependent cleavage and secretion of the synaptic molecule and glioma mitogen neuroligin-3 (Nlgn3), but the therapeutic potential of targeting Nlgn3 in glioma remains to be defined. We demonstrate a striking dependence of HGG growth on microenvironmental Nlgn3 and determine a targetable mechanism of secretion. Patient-derived orthotopic xenografts of pediatric glioblastoma, diffuse intrinsic pontine glioma and adult glioblastoma fail to grow in Nlgn3 knockout mice. Glioma exposure to Nlgn3 results in numerous signaling consequences, including early focal adhesion kinase activation upstream of PI3K-mTOR. Nlgn3 is cleaved from both neurons and oligodendrocyte precursor cells via the ADAM10 sheddase. Administration of ADAM10 inhibitors robustly blocks HGG xenograft growth. This work defines the therapeutic potential of and a promising strategy for targeting Nlgn3 secretion in the glioma microenvironment, which could prove transformative for treatment of HGG.
Project description:The goal of this study was to profile gene expression differences between autochthonous mouse models of high-grade glioma (HGG) and ependymoma (EPN). Furthermore, with the objective of how transcription factor Sox9 affect gene expression in these two models, we also profiled gene expression differences between HGG and EPN after Sox9 overexpression (Sox9-GOF) or deletion (Sox9-LOF) in each of these models.
Project description:Aims and methods: astroblastoma is a rare glial brain tumor with singular morphology. Recurrent MN1-BEND2 fusions have been recently identified in most of pediatric cases. Adolescent and adult cases, however, remain molecularly poorly defined. Here, we performed clinical and molecular characterization of a retrospective cohort of 14 adult and one adolescent gliomas with astroblastic features. Results: strikingly, we found MN1 fusions a rare event in this age group (1/15). Using methylation profiling and targeted sequencing, most cases were reclassified as either pleomorphic xanthoastrocytomas (PXA) or high-grade glioma (HGG). PXA-like ABM show BRAF mutation (6/7 with V600E mutation and 1/7 with G466E mutation) and CD34 expression. Conversely, HGG-like ABM harbored specific mutations of diffuse midline glioma (2/5) or glioblastoma (3/5). These latter patients showed an unfavorable clinical course with significantly shorter overall survival (p = 0.027). MAPK pathway alterations (including FGFR fusion, BRAF and NF1 mutations) were present in 10 of 15 patients and overrepresented in the HGG group (3/5) compared to previously reported prevalence of these alterations in GBM and diffuse midline glioma. Conclusion: We suggest that astroblastoma comprises a variety of molecularly sharply defined entities. Adults’ astroblastomas harboring molecular features of PXA and HGG should be reclassified. CNS high-grade neuroepithelial tumors with MN1 alterations appears to be a truly pediatric entity and is uncommon in adult cases with a histology of astroblastoma. Astroblastic morphology in adults should thus prompt thorough molecular investigation aiming at a clear histomolecular diagnosis and identifying actionable drug targets, especially in MAPK pathway.
Project description:This was a Phase II, open-label, non-randomized, multi-center study of oral dabrafenib in combination with oral trametinib in subjects with rare cancers harboring the BRAF V600E mutation including anaplastic thyroid cancer (ATC), biliary tract cancer (BTC), gastrointestinal stromal tumor (GIST), low grade (WHO G1/G2) glioma (LGG), high grade (WHO G3/G4) glioma (HGG), non-seminomatous germ cell tumors (NSGCT) / non-germinomatous germ cell tumors (NGGCT), adenocarcinoma of the small intestine (ASI), hairy cell leukemia (HCL) and multiple myeloma (MM).
Project description:The goal of this study was to profile active H3K27ac marks between autochthonous mouse models of high-grade glioma (HGG) and ependymoma (EPN). Furthermore, with the objective of how transcription factor Sox9 affect H3K27ac states in these two models, we also profiled H3K27ac status between HGG and EPN after Sox9 overexpression (Sox9-GOF) or deletion (Sox9-LOF) in each of these models. In addition, we extended our studies to evaluate both H3K27ac and Sox9 states in human HGG and mouse EPN derived tumor cells.
Project description:High-grade gliomas (HGG) are deadly diseases for both adult and pediatric patients. Recently, it has been shown that neuronal activity promotes the progression of multiple subgroups of HGG. However, epigenetic mechanisms that govern this process remain elusive. Here we report that the chromatin remodeler CHD2 regulates neuron-glioma interactions in diffuse midline glioma (DMG) characterized by onco-histone H3.1K27M. Depletion of CHD2 in H3.1K27M DMG cells compromises cell viability and neuron-to-glioma synaptic connections in vitro, neuron-induced proliferation of H3.1K27M HGG DMG cells in vitro and in vivo, activity-dependent calcium transients in vivo, and extends the survival of H3.1K27M DMG-bearing mice. Mechanistically, CHD2 coordinates with the transcription factor FOSL1 to control the expression of axon-guidance and synaptic genes in H3.1K27M DMG cells. Together, our study reveals a mechanism whereby CHD2 controls the intrinsic gene program of the H3.1K27M DMG subtype, which in turn regulates the tumor growth-promoting interactions of glioma cells with neurons.