BET bromodomain Inhibition Potentiates Radiosensitivity by Reprograming DNA Damage Repair in H3K27M-Mutant Glioma
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PROVIDER: PRJNA991617 | ENA |
REPOSITORIES: ENA
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Project description:Diffuse intrinsic pontine glioma (DIPG) is one of the devastating childhood cancers. Radiation therapy remains the only effective treatment yet provides a 5-year survival rate of only1%. Several clinical trials have attempted to enhance radiation anti-tumor activity using radiosensitizing agents, though none have been successful in doing so. Given this, there is a critical need for identifying effective therapeutics to enhance radiation sensitivity for the treatment of DIPG. Using high-throughput radiosensitivity screening, we identified bromo- and extra-terminal domain (BET) protein inhibitors as potent radiosensitizers in DIPG. Genetic and pharmacologic inhibition of BET bromodomain activity reduced DIPG cell proliferation and enhanced radiation-induced DNA damage by inhibiting DNA repair pathways. RNA- and CUT-RUN-sequencing showed that BET bromodomain inhibitors regulate the expression of DNA repair genes mediated by H3K27acetylation at enhancers. BET bromodomain inhibitors enhanced DIPG radiation-response in patient-derived xenografts as well as genetically engineered mouse models. Together, our results highlight BET bromodomain inhibitor as a novel radiosensitizer and provide a rationale for developing combination therapy with radiation for the treatment DIPG.
2023-12-01 | GSE236598 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumour that is located in the pons and primarily affects children. Whole-exome sequencing studies have identified recurrent driver mutations in H3F3A and HIST1H3B, leading to the expression of histone H3 in which lysine 27 is substituted with methionine (H3K27M) in nearly 80% of DIPGs. H3K27M has been shown to inhibit Polycomb Repressive Complex 2 (PRC2) activity by binding to its catalytic subunit EZH2, and although DIPGs with H3K27M mutation show global loss of H3 with trimethylated lysine 27 (H3K27me3), several genes retain H3K27me3. Here, we describe a new mouse DIPG model in which H3K27M potentiates tumourigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M expressing tumours require PRC2 for proliferation. Furthermore, we demonstrate that small molecule EZH2 inhibitors abolish tumour cell growth through a mechanism involving induction of the tumour suppressor protein p16INK4A. In agreement with this, we show that tumour cells with non-functional p16INK4A do not respond to EZH2 inhibitors. Genome-wide enrichment analyses show that several genes retain H3K27me3 even in the presence of H3K27M. Several of these genes are associated with high levels of H3K27me3 in the absence of H3K27M, whereas regions with low H3K27me3 levels tend to lose H3K27me3 upon H3K27M expression. Furthermore, we find significant overlap between genes that retain H3K27me3 in mouse and human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M positive DIPGs, and we propose a therapeutic strategy for these tumours using EZH2 inhibitors and expression of p16INK4A as a marker for stratifying potential responding tumours.
2017-08-31 | GSE71225 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumour that is located in the pons and primarily affects children. Whole-exome sequencing studies have identified recurrent driver mutations in H3F3A and HIST1H3B, leading to the expression of histone H3 in which lysine 27 is substituted with methionine (H3K27M) in nearly 80% of DIPGs. H3K27M inhibits Polycomb Repressive Complex 2 (PRC2) activity by binding to its catalytic subunit EZH2 and although DIPGs with H3K27M mutation show global loss of H3 with trimethylated lysine 27 (H3K27me3), several genomic loci are still H3K27me3 positive. Here, we describe a new mouse DIPG model in which H3K27M potentiates tumourigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M expressing tumours require PRC2 for proliferation. Furthermore, we demonstrate that small molecule EZH2 inhibitors abolish in vitro and in vivo tumour cell growth through a mechanism involving induction of the tumour suppressor protein p16INK4A. In agreement with this, we show that tumour cells with inactivated p16INK4A function do not respond to EZH2 inhibitors. By analysing genome-wide H3K27me3 enrichment profile in mouse DIPG model, we highlight distinct features of the loci that lose or retain H3K27me3 in H3K27M expressing cells. Taken together these results show that residual PRC2 activity is required for the proliferation of H3K27M positive DIPGs, and we propose a therapeutic strategy for these tumours using EZH2 inhibitors and expression of p16INK4A as a marker for stratifying potential responding tumours.
2017-08-31 | GSE71387 | GEO
Project description:BET bromodomain inhibition potentiates ocular melanoma therapy by inducing cell cycle arrest
| PRJNA976712 | ENA
Project description:Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumour that is located in the pons and primarily affects children. Whole-exome sequencing studies have identified recurrent driver mutations in H3F3A (H3.3) and HIST1H3B (H3.1), leading to the expression of histone H3 in which lysine 27 is substituted with methionine (H3K27M) in nearly 80% of DIPGs1-5. H3K27M has been shown to inhibit Polycomb Repressive Complex 2 (PRC2) activity by binding to its catalytic subunit EZH2, and although DIPGs with H3K27M mutation show global loss of H3 with trimethylated lysine 27 (H3K27me3), several genes retain H3K27me3 (Refs. 1-8). Here, we describe a mouse DIPG model in which H3K27M potentiates tumourigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M expressing tumours require PRC2 for proliferation. Furthermore, we demonstrate that small molecule EZH2 inhibitors abolish tumour cell growth through a mechanism that is dependent on the induction of the tumour suppressor protein p16INK4A. Genome-wide enrichment analyses show that the genes that retain H3K27me3 in H3K27M cells are strong polycomb targets and are highly enriched for H3K27me3/PRC2/PRC1 in cells prior to H3K27M expression. Furthermore, we find a highly significant overlap between genes that retain H3K27me3 in the mouse DIPG model and in human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M positive DIPGs, and inhibition of EZH2 is as a potential therapeutic strategy for the treatment of these tumours.
2017-02-28 | GSE85388 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumour that is located in the pons and primarily affects children. Whole-exome sequencing studies have identified recurrent driver mutations in H3F3A (H3.3) and HIST1H3B (H3.1), leading to the expression of histone H3 in which lysine 27 is substituted with methionine (H3K27M) in nearly 80% of DIPGs1-5. H3K27M has been shown to inhibit Polycomb Repressive Complex 2 (PRC2) activity by binding to its catalytic subunit EZH2, and although DIPGs with H3K27M mutation show global loss of H3 with trimethylated lysine 27 (H3K27me3), several genes retain H3K27me3 (Refs. 1-8). Here, we describe a mouse DIPG model in which H3K27M potentiates tumourigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M expressing tumours require PRC2 for proliferation. Furthermore, we demonstrate that small molecule EZH2 inhibitors abolish tumour cell growth through a mechanism that is dependent on the induction of the tumour suppressor protein p16INK4A. Genome-wide enrichment analyses show that the genes that retain H3K27me3 in H3K27M cells are strong polycomb targets and are highly enriched for H3K27me3/PRC2/PRC1 in cells prior to H3K27M expression. Furthermore, we find a highly significant overlap between genes that retain H3K27me3 in the mouse DIPG model and in human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M positive DIPGs, and inhibition of EZH2 is as a potential therapeutic strategy for the treatment of these tumours.
2017-02-28 | GSE85387 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumour that is located in the pons and primarily affects children. Whole-exome sequencing studies have identified recurrent driver mutations in H3F3A (H3.3) and HIST1H3B (H3.1), leading to the expression of histone H3 in which lysine 27 is substituted with methionine (H3K27M) in nearly 80% of DIPGs1-5. H3K27M has been shown to inhibit Polycomb Repressive Complex 2 (PRC2) activity by binding to its catalytic subunit EZH2, and although DIPGs with H3K27M mutation show global loss of H3 with trimethylated lysine 27 (H3K27me3), several genes retain H3K27me3 (Refs. 1-8). Here, we describe a mouse DIPG model in which H3K27M potentiates tumourigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M expressing tumours require PRC2 for proliferation. Furthermore, we demonstrate that small molecule EZH2 inhibitors abolish tumour cell growth through a mechanism that is dependent on the induction of the tumour suppressor protein p16INK4A. Genome-wide enrichment analyses show that the genes that retain H3K27me3 in H3K27M cells are strong polycomb targets and are highly enriched for H3K27me3/PRC2/PRC1 in cells prior to H3K27M expression. Furthermore, we find a highly significant overlap between genes that retain H3K27me3 in the mouse DIPG model and in human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M positive DIPGs, and inhibition of EZH2 is as a potential therapeutic strategy for the treatment of these tumours.
2017-02-28 | GSE85385 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumour that is located in the pons and primarily affects children. Whole-exome sequencing studies have identified recurrent driver mutations in H3F3A (H3.3) and HIST1H3B (H3.1), leading to the expression of histone H3 in which lysine 27 is substituted with methionine (H3K27M) in nearly 80% of DIPGs1-5. H3K27M has been shown to inhibit Polycomb Repressive Complex 2 (PRC2) activity by binding to its catalytic subunit EZH2, and although DIPGs with H3K27M mutation show global loss of H3 with trimethylated lysine 27 (H3K27me3), several genes retain H3K27me3 (Refs. 1-8). Here, we describe a mouse DIPG model in which H3K27M potentiates tumourigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M expressing tumours require PRC2 for proliferation. Furthermore, we demonstrate that small molecule EZH2 inhibitors abolish tumour cell growth through a mechanism that is dependent on the induction of the tumour suppressor protein p16INK4A. Genome-wide enrichment analyses show that the genes that retain H3K27me3 in H3K27M cells are strong polycomb targets and are highly enriched for H3K27me3/PRC2/PRC1 in cells prior to H3K27M expression. Furthermore, we find a highly significant overlap between genes that retain H3K27me3 in the mouse DIPG model and in human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M positive DIPGs, and inhibition of EZH2 is as a potential therapeutic strategy for the treatment of these tumours.
2017-02-28 | GSE85386 | GEO
Project description:Nasopharyngeal carcinoma is a squamous cell carcinoma arising from the nasopharynx epithelium. So far, there have been no effective biomarkers to predict the radiosensitivity of NPC. Based on miRNA profile screened out from NPC patients with different radiosensitivity, this study was conducted to explore the correlation between serum miRNAs and radiotherapy response in NPC, and to identify biomarkers for predicting the radiosensitivity of NPC.
2020-03-30 | GSE139164 | GEO
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