Epigenetic changes in human DIPG cells with histone H3K27M mutations [ATAC-seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE135418 | GEO | 2020/06/24
REPOSITORIES: GEO
Similar Datasets
Project description:The lysine-to-methionine mutation at residue 27 of histone H3 (H3K27M) is a driving mutation in Diffuse Intrinsic Pontine Glioma (DIPG), a highly aggressive form of pediatric brain tumor with no effective treatment and little chance of survival. H3K27M reshapes the epigenome through a global inhibition of PRC2 catalytic activity, displacement of methylation at lysine 27 of histone H3 (H3K27me2/3), and thus promoting oncogenesis of DIPG. As a consequence, a histone modification H3K36me2, antagonistic to H3K27me2/3, is aberrantly elevated. Here, we investigate the role of H3K36me2 in H3K27M-DIPG by tackling its upstream catalyzing enzymes (writers) and downstream binding factors (readers). We determine that NSD1 and NSD2 are the key writers for H3K36me2. Loss of NSD1/2 in H3K27M-DIPG impedes cellular proliferation in vitro and tumorigenesis in vivo, and disrupts tumor-promoting gene expression programs. Further, we demonstrate that LEDGF and HDGF2 are the main readers that mediate the pro-tumorigenic effects downstream of NSD1/2-H3K36me2. Treatment with a chemically modified peptide mimicking endogenous H3K36me2 dislodges LEDGF/HDGF2 from chromatin and specifically inhibits the proliferation of H3K27M-DIPG. Together, our results indicate a functional pathway of NSD1/2-H3K36me2-LEDGF/HDGF2 as an acquired dependency in H3K27M-DIPG and suggest a possibility to target this pathway for therapeutic interventions.
2021-07-21 | GSE174006 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is a rare and fatal pediatric brain cancer without cure. DIPG has high percentage histone mutation at K27M on histone H3 locus, which is believed to be one of the drivers of the tumorigenesis. Dysregulation of G1/S cell cycle checkpoint is more enriched in the H3.3K27M mutant subgroup. In this study, we reported that palbociclib (PD0332991), a specific and cytostatic inhibitor of CDK4/6, effectively suppresses the growth of DIPG cells in vitro and in vivo. We established patient derived cell lines from treatment-naïve specimens, which all have H3.3K27M mutation. And our DIPG cell lines with H3.3K27M mutation have high CDK4/6 expression. Then, we showed that depletion of CDK4 or CDK6 inhibits DIPG cells growth and blocks G1/S transition. Furthermore, palbociclib effectively repressed all 8 cell lines self-renewal, proliferation and cell cycle progression from G1 to S phase in vitro. Transcriptome analysis showed that palbociclib not only blocks G1/S transition, it also blocks other oncogenic targets such as Myc. Finally, palbociclib activity was assayed in vivo against DIPG orthotropic xenografts to demonstrate the high efficiency of blocking tumor growth. Our findings revealed that palbociclib could be the therapy strategy for DIPG.
2019-06-20 | GSE115976 | GEO
Project description:We studied the effect of BMI1 inhibition in diffuse intrinsic pontine glioma cells (DIPG). We reported the application of chromatin immunoprecipitation sequencing for high-thoughput profiling of BMI1 and H2AK119ub in diffuse intrinsic pontine glioma cells (DIPG) in response to BMI1 inhibition. We also performed bulk RNA sequencing of DIPG cells in response to pharmacological inhibition or knockdown of BMI1.
2020-10-22 | GSE140768 | GEO
Project description:Epigenetic changes in human DIPG cells with histone H3K27M mutations [ATAC-seq]
| PRJNA558794 | ENA
Project description:Background: The histone variant H3.3 K27M mutation is a defining characteristic of diffuse intrinsic pontine glioma (DIPG)/diffuse midline glioma (DMG). This histone mutation is responsible for major alterations to histone H3 post-translational modification (PTMs) and subsequent aberrant gene expression. However, much less is known about the effect this mutation has on chromatin structure and function, including open versus closed chromatin regions as well as their transcriptomic consequences. Results: Recently, we developed isogenic CRISPR-edited DIPG cell lines that are wild- type for histone H3.3 that can be compared to their matched K27M lines. Here we show via ATAC-seq analysis that H3.3K27M glioma cells have unique accessible chromatin at regions corresponding to neurogenesis, NOTCH, and neuronal development pathways and associated genes that are overexpressed in H3.3K27M compared to our isogenic wild-type cell line. As to mechanisms, accessible enhancers and super-enhancers corresponding to increased gene expression in H3.3K27M cells were also mapped to genes involved in neurogenesis and NOTCH signaling, suggesting that these pathways are key to DIPG tumor maintenance. Motif analysis implicates specific transcription factors as central to the neuro-oncogenic K27M signaling pathway including, in particular, ASCL1 and NEUROD1. Conclusions: Altogether our findings indicate that H3.3K27M causes chromatin to take on a more accessible configuration at key regulatory regions for NOTCH and neurogenesis genes resulting in increased oncogenic gene expression, which is at least partially reversible upon editing K27M back to wild- type.
2022-04-24 | GSE201265 | GEO
Project description:H3.3K27M mutations or H3.3 WT were expressed in in neuronal stem cells (Nsc) derived from p16Ink4a/p14Arf knockout (KO) animal. Genomic changes in H3K27me3, H3K27ac and H3K4me3 were assessed between H3.3K27M and H3.3WT cells.
2021-08-05 | GSE135417 | GEO
Project description:The H3K36me2 writer-reader dependency in H3K27M-DIPG
| PRJNA727843 | ENA
Project description:Histone H3K27M is a driving mutation in diffuse intrinsic pontine glioma (DIPG), a deadly pediatric brain tumor. H3K27M reshapes the epigenome through a global inhibition of PRC2 catalytic activity and displacement of H3K27me2/3, promoting oncogenesis of DIPG. As a consequence, a histone modification H3K36me2, antagonistic to H3K27me2/3, is aberrantly elevated. Here, we investigate the role of H3K36me2 in H3K27M-DIPG by tackling its upstream catalyzing enzymes (writers) and downstream binding factors (readers). We determine that NSD1 and NSD2 are the key writers for H3K36me2. Loss of NSD1/2 in H3K27M-DIPG impedes cellular proliferation and tumorigenesis by disrupting tumor-promoting transcriptional programs. Further, we demonstrate that LEDGF and HDGF2 are the main readers mediating the protumorigenic effects downstream of NSD1/2-H3K36me2. Treatment with a chemically modified peptide mimicking endogenous H3K36me2 dislodges LEDGF/HDGF2 from chromatin and specifically inhibits the proliferation of H3K27M-DIPG. Our results indicate a functional pathway of NSD1/2-H3K36me2-LEDGF/HDGF2 as an acquired dependency in H3K27M-DIPG.
| S-EPMC8279504 | biostudies-literature
Project description:Diffuse intrinsic pontine gliomas (DIPG) are devastating pediatric brain tumors for which there is no effective therapy. A lack of pre-clinical genetic models has affected efforts to develop therapies targeted to DIPG. Over 60% of DIPG patients carry a mutation in the histone H3F3A gene (H3.3K27M) that is often accompanied by a mutation in the TP53 gene. Here we created a genetic model in which H3.3K27M is expressed under the mouse Fabp7 promoter. These mice have disrupted embryonic development and increased susceptibility to development of lymphomas. Crosses to Trp53 knockout mice further accelerated lymphomagenesis and led to brain tumour development. Some but not all tumours acquired additional oncogenic alterations. The brain tumours faithfully recapitulate the expression profiles of DIPG patients, and brain tumours and lymphomas share significant similarities in pathway alterations, pointing to a core H3.3K27M transcriptome. Overall, this mouse model provides key insights into how H3.3K27M mutations regulate DIPG at the cellular and tumour level.
2020-10-27 | GSE120883 | GEO
Project description:Diffuse intrinsic pontine gliomas (DIPG) are devastating pediatric brain tumors for which there is no effective therapy. A lack of pre-clinical genetic models has affected efforts to develop therapies targeted to DIPG. Over 60% of DIPG patients carry a mutation in the histone H3F3A gene (H3.3K27M) that is often accompanied by a mutation in the TP53 gene. Here we created a genetic model in which H3.3K27M is expressed under the mouse Fabp7 promoter. These mice have disrupted embryonic development and increased susceptibility to development of lymphomas. Crosses to Trp53 knockout mice further accelerated lymphomagenesis and led to brain tumour development. Some but not all tumours acquired additional oncogenic alterations. The brain tumours faithfully recapitulate the expression profiles of DIPG patients, and brain tumours and lymphomas share significant similarities in pathway alterations, pointing to a core H3.3K27M transcriptome. Overall, this mouse model provides key insights into how H3.3K27M mutations regulate DIPG at the cellular and tumour level.
2020-10-27 | GSE120882 | GEO