Gene expression profile at single cell level of Anaplastic ependymoma (EPN) and H3K27M-mutant diffuse midline glioma (BG)
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE245674 | GEO | 2024/02/28
REPOSITORIES: GEO
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Project description:Ependymoma (EPN) is a type of brain tumour.. Here we present a novel subtype of spinal ependymoma, that shows an anaplastic morphology, OLIG2 and MYCN positvity in immunostaining and a distinct epigenetic and proteomic profile.
2024-05-22 | GSE264714 | GEO
Project description:Posterior fossa A (PFA) ependymomas comprise one out of nine molecular groups of ependymoma. PFA tumors are mainly diagnosed in infants and young children, show a poor prognosis and are characterized by a lack of the repressive histone H3 lysine 27 trimethylation (H3K27me3) mark. Recently, we reported CXorf67 overexpression as hallmark of PFA ependymoma and showed that CXorf67 can interact with EZH2 thereby inhibiting polycomb repressive complex 2 (PRC2). Here, we report that the inhibitory mechanism of this interaction is similar as in diffuse midline gliomas harboring H3K27M mutations. A small, highly conserved peptide sequence located in the C-terminal region of CXorf67 mimics the H3K27M peptide and binds to the SET domain of EZH2. This interaction blocks EZH2 methyltransferase activity and causes H3K27 hypomethylation, an oncogenic mechanism that may be exploited for targeted therapy in PFA ependymoma. Based on its function, we have renamed CXorf67 into EZH2 Inhibitory Protein (EZHIP).
2019-07-08 | PXD012318 | Pride
Project description:Diffuse intrinsic pontine glioma (DIPG) and other H3K27M-mutated diffuse midline gliomas (DMGs) are universally lethal central nervous system (CNS) tumors that occur most commonly in children and young adults1. Average life expectancy is ten months from diagnosis, and 5-year survival is less than 1%2. Palliative radiotherapy is the only established treatment3, and neither cytotoxic nor targeted pharmacological approaches have demonstrated anti-tumor responses or improved prognosis to date3,4. We previously discovered that the disialoganglioside GD2 is highly and uniformly expressed on H3K27M+ DMG cells and demonstrated that intravenously (IV) administered GD2.4-1BB.z chimeric antigen receptor (CAR) T-cells eradicated established DMGs in patient-derived orthotopic murine models5, thereby providing the rationale for a first-in-human/first-in-child Phase 1 clinical trial (NCT04196413). Because CAR T-cell-induced inflammation and edema of the brainstem can result in obstructive hydrocephalus, increased intracranial pressure, and dangerous tissue shifts, a number of neurocritical care precautions were incorporated in the clinical trial design and management plan. Here we present the clinical experience from the first four patients with H3K27M+ DMG treated with GD2-CAR T-cells at dose level 1 (DL1; 1e6 GD2-CAR T-cells/kg administered IV). Patients who exhibited clinical benefit were eligible for subsequent administrations of GD2-CAR T-cells. Given preclinical evidence for increased CAR T-cell potency6, and the potential for diminished immunogenicity with locoregional administration, second doses were administered intracerebroventricularly (ICV) through an Ommaya catheter to three patients. As predicted from preclinical models, toxicity was largely related to the neuroanatomical location of the tumors and was reversible with intensive supportive care. Although GD2 is expressed at low levels in normal neural tissue, no evidence of on-target, off-tumor toxicity was observed. Three of four patients exhibited clinical and radiographic improvement, underscoring the promise of this approach for H3K27M+ DMG therapy. Correlative studies of serum and CSF revealed marked proinflammatory cytokine production following GD2 CAR T cell administration and single cell transcriptomic analysis of 65,598 single cells from CAR T cell products and patient CSF has begun to reveal differences that correlate with the heterogeneity between subjects and routes of administration.
2022-02-07 | GSE186802 | GEO
Project description:GD2-CAR T-cell therapy for H3K27M-mutated diffuse midline gliomas
| PRJNA776146 | ENA
Project description:Giant cell ependymoma (GCE), a rare ependymoma subtype, was only recently recognised as a separate diagnostic entity with variations both in malignant potential and in course of disease. The pathogenetic mechanisms behind ependymomas remain unknown. Only one karyotyped GCE has so far been reported. We present the first genomic characterisation of a supratentorial GCE using G-band karyotyping, DNA ploidy analysis and array comparative genomic hybridisation (aCGH). The G-banded karyotype was hypodiploid with multiple monosomies, a feature present also in the previously published case and, hence, probably characteristic of these tumours. We could also analyse cytogenetically a subsequent recurrent tumour, phenotypically an anaplastic ependymoma, but exhibiting a pattern of monosomies largely similar to that found in the primary tumour, allowing a first insight into the genetic events involved also in disease progression. 2 tumour samples analysed with the control DNA (supplied by Agilent)
2010-08-30 | E-GEOD-23065 | biostudies-arrayexpress
Project description:Diffuse midline gliomas (DMGs) are uniformly fatal pediatric central nervous system cancers, refractory to standard of care therapeutic modalities. The primary genetic drivers are a set of recurrent amino acid substitutions in genes encoding histone H3 (H3.3 and H3.1, K27M), which are currently undruggable. These H3K27M oncohistones perturb normal chromatin architecture, resulting in an aberrant epigenetic landscape, which we interrogated here for epigenetic dependencies using a CRISPR screen in patient-derived H3K27M-glioma neurospheres. We show that H3K27M-glioma cells are dependent on core components of the mammalian SWI/SNF (BAF) chromatin remodeling complex for maintaining glioma stem cells in a cycling, oligodendrocyte precursor cell (OPC)-like state. Genetic perturbation of the BAF catalytic subunit SMARCA4 (BRG1), as well as pharmacological suppression opposes proliferation, promotes differentiation, and improves overall survival of patient-derived xenograft (PDX) models. In summary, we demonstrate that therapeutic inhibition of BAF complex has translational potential for children with H3K27M-gliomas.
2022-09-15 | GSE212782 | GEO
Project description:Diffuse midline gliomas (DMGs) are uniformly fatal pediatric central nervous system cancers, refractory to standard of care therapeutic modalities. The primary genetic drivers are a set of recurrent amino acid substitutions in genes encoding histone H3 (H3.3 and H3.1, K27M), which are currently undruggable. These H3K27M oncohistones perturb normal chromatin architecture, resulting in an aberrant epigenetic landscape, which we interrogated here for epigenetic dependencies using a CRISPR screen in patient-derived H3K27M-glioma neurospheres. We show that H3K27M-glioma cells are dependent on core components of the mammalian SWI/SNF (BAF) chromatin remodeling complex for maintaining glioma stem cells in a cycling, oligodendrocyte precursor cell (OPC)-like state. Genetic perturbation of the BAF catalytic subunit SMARCA4 (BRG1), as well as pharmacological suppression opposes proliferation, promotes differentiation, and improves overall survival of patient-derived xenograft (PDX) models. In summary, we demonstrate that therapeutic inhibition of BAF complex has translational potential for children with H3K27M-gliomas.
2022-09-15 | GSE212700 | GEO
Project description:Diffuse midline gliomas (DMGs) are uniformly fatal pediatric central nervous system cancers, refractory to standard of care therapeutic modalities. The primary genetic drivers are a set of recurrent amino acid substitutions in genes encoding histone H3 (H3.3 and H3.1, K27M), which are currently undruggable. These H3K27M oncohistones perturb normal chromatin architecture, resulting in an aberrant epigenetic landscape, which we interrogated here for epigenetic dependencies using a CRISPR screen in patient-derived H3K27M-glioma neurospheres. We show that H3K27M-glioma cells are dependent on core components of the mammalian SWI/SNF (BAF) chromatin remodeling complex for maintaining glioma stem cells in a cycling, oligodendrocyte precursor cell (OPC)-like state. Genetic perturbation of the BAF catalytic subunit SMARCA4 (BRG1), as well as pharmacological suppression opposes proliferation, promotes differentiation, and improves overall survival of patient-derived xenograft (PDX) models. In summary, we demonstrate that therapeutic inhibition of BAF complex has translational potential for children with H3K27M-gliomas.
2022-09-15 | GSE212718 | GEO
Project description:Diffuse midline gliomas (DMGs) are uniformly fatal pediatric central nervous system cancers, refractory to standard of care therapeutic modalities. The primary genetic drivers are a set of recurrent amino acid substitutions in genes encoding histone H3 (H3.3 and H3.1, K27M), which are currently undruggable. These H3K27M oncohistones perturb normal chromatin architecture, resulting in an aberrant epigenetic landscape, which we interrogated here for epigenetic dependencies using a CRISPR screen in patient-derived H3K27M-glioma neurospheres. We show that H3K27M-glioma cells are dependent on core components of the mammalian SWI/SNF (BAF) chromatin remodeling complex for maintaining glioma stem cells in a cycling, oligodendrocyte precursor cell (OPC)-like state. Genetic perturbation of the BAF catalytic subunit SMARCA4 (BRG1), as well as pharmacological suppression opposes proliferation, promotes differentiation, and improves overall survival of patient-derived xenograft (PDX) models. In summary, we demonstrate that therapeutic inhibition of BAF complex has translational potential for children with H3K27M-gliomas.
2022-09-15 | GSE212679 | GEO
Project description:Posterior fossa ependymoma comprise three distinct molecular variants, termed PF-EPN-A (PFA), PF-EPN-B (PFB), and PF-EPN-SE (subependymoma). Clinically, they are very disparate and PFB tumors are currently being considered for a trial of radiation avoidance. However, to move forward, unraveling the heterogeneity within PFB would be highly desirable. To discern the molecular heterogeneity within PFB, we performed an integrated analysis consisting of DNA methylation profiling, copy-number profiling, gene expression profiling, and clinical correlation across a cohort of 212 primary posterior fossa PFB tumors. Unsupervised spectral clustering and t-SNE analysis of genome-wide methylation data revealed five distinct subtypes of PFB tumors, termed PFB1-5, with distinct demographics, copy-number alterations, and gene expression profiles. All PFB subtypes were distinct from PFA and posterior fossa subependymomas. Of the five subtypes, PFB4 and PFB5 are more discrete, consisting of younger and older patients, respectively, with a strong female-gender enrichment in PFB5 (age: p = 0.011, gender: p = 0.04). Broad copy-number aberrations were common; however, many events such as chromosome 2 loss, 5 gain, and 17 loss were enriched in specific subtypes and 1q gain was enriched in PFB1. Late relapses were common across all five subtypes, but deaths were uncommon and present in only two subtypes (PFB1 and PFB3). Unlike the case in PFA ependymoma, 1q gain was not a robust marker of poor progression-free survival; however, chromosome 13q loss may represent a novel marker for risk stratification across the spectrum of PFB subtypes. Similar to PFA ependymoma, there exists a significant intertumoral heterogeneity within PFB, with distinct molecular subtypes identified. Even when accounting for this heterogeneity, extent of resection remains the strongest predictor of poor outcome. However, this biological heterogeneity must be accounted for in future preclinical modeling and personalized therapies.
| S-EPMC6373486 | biostudies-literature