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.
Project description:Genome wide DNA methylation profiling of an H3K27M-mutant diffuse gliomas with a non-midline location. The Illumina Infinium Human EPIC DNA methylation Beadchip was used to obtain DNA methylation profiles from more than 850,000 CpGs from a FFPE sample.
Project description:Genome wide DNA methylation profiling of an H3K27M-mutant diffuse gliomas with a non-midline location. The Illumina Infinium Human EPICV2 DNA methylation Beadchip was used to obtain DNA methylation profiles across more than 935,000 CpGs from a FFPE sample.
Project description:PDGFRA is commonly altered in pediatric high grade gliomas including in histone 3 lysine 27-mutated diffuse midline gliomas (H3K27M DMG), a disease with almost no long-term survivors. We describe effective CNS penetration of a PDGFRA inhibitor with pharmacologically relevant concentrations in brain tumor tissue resulting in dramatic clinical effect and minimal side effects in a cohort of 9 pediatric high grade glioma cases.
Project description:Recurrent driver mutations in genes encoding histone H3 (H3.3K27M and H3.1K27M) are observed in ~80% of diffuse midline gliomas (DMG), which lead to aberrant gene regulation, yet the specific RNA polymerase 2 (Pol2) regulators inducing aberrant DMG transcription are not fully defined. We identified multiple regulators of Pol2 elongation as DMG genetic dependencies in a chromatin-focused CRISPR screen. Additional studies confirm that knockout (KO) of the Pol2 SIII complex gene Elongin B (ELOB) inhibits DMG cell proliferation in tissue culture and tumor growth in xenograft models. Further genomic analyses reveal that ELOB binding sites are enriched in H3K27M oncohistones and that ELOB knockout alters H3K27me3 and H3K27M incorporation at thousands of genomic regions, suggesting a role for ELOB in maintaining dysfunctional chromatin states in DMG. Correspondingly, ELOB loss disrupts Pol2 transcriptional activity and alters the expression of transcripts involved in metabolism, proliferation, and brain development. These findings suggest that Pol2 elongation factors cooperate with H3K27M oncohistones to maintain the epigenetic and transcriptional landscape driving DMG malignancy.
Project description:Recurrent driver mutations in genes encoding histone H3 (H3.3K27M and H3.1K27M) are observed in ~80% of diffuse midline gliomas (DMG), which lead to aberrant gene regulation, yet the specific RNA polymerase 2 (Pol2) regulators inducing aberrant DMG transcription are not fully defined. We identified multiple regulators of Pol2 elongation as DMG genetic dependencies in a chromatin-focused CRISPR screen. Additional studies confirm that knockout (KO) of the Pol2 SIII complex gene Elongin B (ELOB) inhibits DMG cell proliferation in tissue culture and tumor growth in xenograft models. Further genomic analyses reveal that ELOB binding sites are enriched in H3K27M oncohistones and that ELOB knockout alters H3K27me3 and H3K27M incorporation at thousands of genomic regions, suggesting a role for ELOB in maintaining dysfunctional chromatin states in DMG. Correspondingly, ELOB loss disrupts Pol2 transcriptional activity and alters the expression of transcripts involved in metabolism, proliferation, and brain development. These findings suggest that Pol2 elongation factors cooperate with H3K27M oncohistones to maintain the epigenetic and transcriptional landscape driving DMG malignancy.
Project description:Recurrent driver mutations in genes encoding histone H3 (H3.3K27M and H3.1K27M) are observed in ~80% of diffuse midline gliomas (DMG), which lead to aberrant gene regulation, yet the specific RNA polymerase 2 (Pol2) regulators inducing aberrant DMG transcription are not fully defined. We identified multiple regulators of Pol2 elongation as DMG genetic dependencies in a chromatin-focused CRISPR screen. Additional studies confirm that knockout (KO) of the Pol2 SIII complex gene Elongin B (ELOB) inhibits DMG cell proliferation in tissue culture and tumor growth in xenograft models. Further genomic analyses reveal that ELOB binding sites are enriched in H3K27M oncohistones and that ELOB knockout alters H3K27me3 and H3K27M incorporation at thousands of genomic regions, suggesting a role for ELOB in maintaining dysfunctional chromatin states in DMG. Correspondingly, ELOB loss disrupts Pol2 transcriptional activity and alters the expression of transcripts involved in metabolism, proliferation, and brain development. These findings suggest that Pol2 elongation factors cooperate with H3K27M oncohistones to maintain the epigenetic and transcriptional landscape driving DMG malignancy.