Contrasting stage-dependent requirements during AML evolution identify EZH2 as a therapeutic target in AML
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ABSTRACT:
PROVIDER: PRJNA448835 | ENA |
REPOSITORIES: ENA
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Project description:Epigenetic regulators are commonly mutated in cancer. Activating mutations and overexpression of the lysine histone methyltransferase EZH2 occur in lymphoma and other malignancies, while loss-of-function mutations are found in myeloid malignancies. We study this apparent contradiction, examining the importance of cellular context for Ezh2 loss during the evolution of a single malignancy, Acute Myeloid Leukemia (AML). Remarkably, we observe diametrically opposite functions for Ezh2 at early and late stages during the evolution of leukemias generated by different AML-associated fusion-oncogenes. During disease maintenance we demonstrate that Ezh2 functions as an oncogene that may be therapeutically targeted. In contrast, Ezh2 acts as a tumour suppressor during AML induction and loss-of-function EZH2 mutations occur early in AML patient samples and confer a poor prognosis. Integrated genomic analysis demonstrates that different expression programmes are de-repressed during AML induction and maintenance following Ezh2 loss. During disease induction, Ezh2 loss de-represses a subset of bivalent promoters that resolve towards gene activation, inducing a feto-oncogene programme including genes such as Plag1, whose overexpression phenocopies Ezh2 loss to accelerate AML induction in mouse models. Our data highlight the importance of cellular context and phase of disease evolution for Ezh2 function. Moreover, we further identify EZH2 as a potential target in AML, whilst providing reassurance of the safety of this therapeutic strategy.
2019-03-07 | GSE112724 | GEO
Project description: Not available
| S-EPMC6446874 | biostudies-literature
Project description:The histone methyltransferases DOT1L (H3K79me1,2,3 KMT, "activating" chromatin mark) and EZH2 (H3K27me1,2,3 KMT, "silencing" mark) have both been shown to be required for growth and survival of KMT2A rearranged AML cells. Both KMTs have been shown to modulate expression of HOXA cluster genes, albeit for EZH2 this has not been shown in the context of KMT2A rearranged AML, but in other subtypes of AML. We asked what transcriptional effects dual inhibition of DOT1L and EZH2 has in KMT2A rearranged AML.
2020-04-29 | GSE149520 | GEO
Project description:The histone methyltransferases DOT1L (H3K79me1,2,3 KMT, "activating" chromatin mark) and EZH2 (H3K27me1,2,3 KMT, "silencing" mark) have both been shown to be required for growth and survival of KMT2A rearranged AML cells. Both KMTs have been shown to modulate expression of HOXA cluster genes, albeit for EZH2 this has not been shown in the context of KMT2A rearranged AML, but in other subtypes of AML. We asked what transcriptional effects dual inhibition of DOT1L and EZH2 has in KMT2A rearranged AML.
2019-07-17 | GSE134369 | GEO
Project description:Chemotherapy resistance is the main impediment in the treatment of acute myeloid leukaemia (AML). Despite rapid advances, the various mechanisms that lead to resistance development remain to be defined in detail. Here we report that loss-of-function mutations (LOF) in the histone methyltransferase EZH2 have the potential to confer resistance against the chemotherapeutic agent cytarabine. We identify seven distinct EZH2 mutations leading to loss of H3K27 trimethylation via multiple mechanisms. Analysis of matched diagnosis and relapse samples reveal a heterogenous regulation of EZH2 and a loss of EZH2 in 50% of patients. We confirm that loss of EZH2 induces resistance against cytarabine in the cell lines HEK293T and K562 as well as in a patient-derived xenograft (PDX) model. Proteomics and transcriptomics analysis reveal that resistance is conferred by upregulation of multiple direct and indirect EZH2 target genes that are involved in apoptosis evasion, augmentation of proliferation and alteration of transmembrane transporter function. Our data indicates, that loss of EZH2 results in upregulation of its target genes, providing the cell with a selective growth advantage, which mediates chemotherapy resistance.
2021-03-12 | PXD023139 | Pride
Project description:The Enhancer of Zeste 2 Polycomb Repressive Complex 2 Subunit (EZH2) is an essential epigenetic modifier able to methylate lysine 27 on histone H3 (H3K27) to induce chromatin compaction, protein complex recruitment and ultimately transcriptional repression. Hematologic malignancies, including Diffuse Large B cell lymphoma (DLBCL) and Acute myeloid leukemia (AML) have shown a high EZH2-mutation frequency (>20%) associated with poor clinical outcomes. Particularly, two distinct oncogenic mutations, so-called gain-of-function (Y641F and A677G) and loss-of-function (H689A and F667I) are found in the catalytic domain of EZH2. In this study, a comprehensive multi-omics approach was employed to characterize downstream effects of H3K27me3 deposition driven by EZH2 mutations. Human embryonic kidney cells (HEK293T) were transfected to generate three stable EZH2 mutants: EZH2(Y641F), EZH2(A677G), and EZH2(H689A/F667I), which were validated via immunoblotting and DIA-MS-based histone profiling assay. Subsequently, constructs were analyzed under a comprehensive multi-omics approach including label-free whole-cell proteomics, acquired with a Bruker timsTOF Pro HPLC-MS/MS with Ion Mobility. Important protein interactors at nuclear level were dysregulated, such as SMYD3 (SET and MYND domain containing 3), NSD2 (nuclear receptor binding SET domain protein 2) and CHD7 (chromodomain helicase DNA binding protein 7), suggesting a cooperative network of chromatin remodelers for gene expression reprogramming.
2023-10-24 | PXD042875 | Pride
Project description:Overexpression of EZH2 in estrogen receptor negative (ER-) breast cancer promotes metastasis. EZH2 has been mainly studied as the catalytic component of the Polycomb Repressive Complex 2 (PRC2) that mediates gene repression by trimethylating histone H3 at lysine 27 (H3K27me3). However, how EZH2 drives metastasis despite the low H3K27me3 levels observed in ER- breast cancer is unknown. We have shown that in human invasive carcinomas and distant metastases, cytoplasmic EZH2 phosphorylated at T367 is significantly associated with ER- disease and low H3K27me3 levels. Here, we explore the interactome of EZH2 and of a phosphodeficient mutant EZH2_T367A. We identified novel interactors of EZH2, and identified interactions that are dependent on the phosphorylation and cellular localization of EZH2 that may play a role in EZH2 dependent metastatic progression.
2018-07-03 | PXD010073 | Pride
Project description:The Enhancer of Zeste 2 Polycomb Repressive Complex 2 Subunit (EZH2) is an essential epigenetic modifier able to methylate lysine 27 on histone H3 (H3K27) to induce chromatin compaction, protein complex recruitment and ultimately transcriptional repression. Hematologic malignancies, including Diffuse Large B cell lymphoma (DLBCL) and Acute myeloid leukemia (AML) have shown a high EZH2-mutation frequency (>20%) associated with poor clinical outcomes. Particularly, two distinct oncogenic mutations, so-called gain-of-function (Y641F and A677G) and loss-of-function (H689A and F667I) are found in the catalytic domain of EZH2. In this study, a comprehensive multi-omics approach was employed to characterize downstream effects of H3K27me3 deposition driven by EZH2 mutations. Human embryonic kidney cells (HEK293T) were transfected to generate three stable EZH2 mutants: EZH2(Y641F), EZH2(A677G), and EZH2(H689A/F667I), which were validated via immunoblotting and DIA-MS-based histone profiling assay. The histone profiling assay demonstrated a significant increase of approximately two-fold in H3.1/H3.3K27me3 for Y641F EZH2 mutant. There was a modest increase in the combinatorial PTMs H3.1/H3.3K27me3K36me1 and a significant depletion in H3.1 and H3.3 K27me2. The most depleted peptide was H3.3K27me2K36me2. For the A677G EZH2 mutant, the assay demonstrated an enrichment on H3.1/H3.3K27me3, combinatorial K27me3K36me1 and a slight increase in K27me1 and K18ac but only on H3.1. The most depleted peptide was H3.3K27me2K36me2. The H689A/F667I cell line has the most alterations in global histone PTMs. The most highly enriched were H3.1/H3.3K36me2, H3.1K9me3 and H3.3K36me1. The most depleted modifications were H3.1K23ac and H3.1K27me3.
2023-10-24 | PXD042953 | Pride
Project description:Abundant evidence has illustrated that long non-coding RNA (lncRNA) plays a vital role in the regulation of tumor development and progression. Most lncRNA have been proven to have biological and clinical significance in acute myeloid leukemia (AML), but further studies remain to be needed. In this study, we investigated lncRNA NR-104098 in AML and its specific mechanism. The microarray analysis was performed on NB4 cells. Based on the related analysis results, we identified that lncRNA NR-104098 is a suppressor gene that is significantly upregulated in AML cells. lncRNA NR-104098 could inhibit proliferation and induce differentiation in AML cells in vitro, and also play main role in the mouse xenografts. Mechanically, it was confirmed that lncRNA NR-104098 may effectively inhibit EZH2 transcription by directly binding E2F1 and recruiting E2F1 to EZH2 promoter. In addition, ATPR can significantly increase the expression of lncRNA NR-104098, whereas knocking down NR104098 can inhibit the inhibitory effect of ATPR on the proliferation and induction differentiation of AML cells. Taken together, these results lead to a deeper insight into the mechanism of ATPR induces AML differentiation and inhibits proliferation by inhibiting EZH2 on transcriptional level.
2020-02-20 | GSE145168 | GEO
Project description:The aim of this study was to identify EZH2 targets in myeloid malignancies. RNA samples from control F-36P, MOLM-13 and OCI-M2 cells (secondary AML after MDS; EZH2 wild type) treated with random shRNA (n = 4, each) and test F-36P, MOLM-13 and OCI-M2 cells treated with either one of two EZH2-targeting shRNAs (n = 4, each) were screened for differential gene expression. RNA from EZH2 wild type (n = 12) and mutant (n = 12) MDS/MPN patients was also analyzed by microarray transcriptome analysis.
2017-06-15 | E-MTAB-5766 | biostudies-arrayexpress