Dual targeting of EZH2 and Histone Deacetylases in hematological malignancies promotes transcriptional and metabolic deregulation leading to ferroptosis. [RNA-Seq]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE254719 | GEO | 2024/07/01
REPOSITORIES: GEO
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Project description:The methyltransferase EZH2 functions as the enzymatic component of the PRC2 complex, which deposits methyl groups on H3K27, leading to chromatin condensation and gene repression. Recent studies have shown that EZH2 can also act as a transcriptional modulator outside of the PRC2 complex independent of its methyltransferase activity. In this study, we first aimed to investigate the effects of EZH2 enzymatic inhibition versus protein degradation. We demonstrate that EZH2 degradation is more effective in blocking cellular proliferation compared to EZH2 enzymatic inhibition, and that EZH2 targeting upregulates the cholesterol biosynthesis pathway. Combined targeting of EZH2 and HDACs showed synergistic effects in a broader spectrum of hematological malignancies. Mechanistically, combined targeting of EZH2 and HDACs induced increased levels of H3K27 acetylation and strong upregulation of cholesterol biosynthesis. This leads to metabolic stress due to acetyl-CoA depletion, ultimately inducing ferroptotic cell death.
2024-07-01 | GSE254724 | GEO
Project description:The Wnt/b-catenin signaling inhibits adipogenesis. Genome-wide profiling studies have revealed the enrichment of histone H3K27 methyltransferase PRC2 on Wnt genes. However, the functional significance of such a direct link between the two types of developmental regulators in mammalian cells, and the role of PRC2 in adipogenesis, remain unclear. Here we show PRC2 and its H3K27 methyltransferase activity are required for adipogenesis. PRC2 directly represses Wnt1, 6, 10a and 10b genes in preadipocytes and during adipogenesis. Deletion of the enzymatic Ezh2 subunit of PRC2 eliminates H3K27me3 on Wnt promoters and de-represses Wnt expression, which leads to activation of Wnt/b-catenin signaling and inhibition of adipogenesis. Ectopic expression of the wild type Ezh2, but not the enzymatically inactive F667I mutant, prevents the loss of H3K27me3 and the defects in adipogenesis in Ezh2-/- preadipocytes. The adipogenesis defects in Ezh2-/- cells can be rescued by expression of adipogenic transcription factors PPARa, C/EBPb, or inhibitors of Wnt/b-catenin signaling. Interestingly, Ezh2-/- cells show marked increase of H3K27 acetylation globally as well as on Wnt promoters. These results indicate that H3K27 methyltransferase PRC2 directly represses Wnt genes to facilitate adipogenesis, and suggest that acetylation and trimethylation on H3K27 play opposing roles in regulating Wnt expression. To identify additional PRC2-regulated genes in preadipocytes, we performed microarray analysis in Ezh2flox/flox preadipocytes infected with retroviruses expressing Cre or vector alone.
2010-03-19 | E-GEOD-20054 | biostudies-arrayexpress
Project description:The Wnt/b-catenin signaling inhibits adipogenesis. Genome-wide profiling studies have revealed the enrichment of histone H3K27 methyltransferase PRC2 on Wnt genes. However, the functional significance of such a direct link between the two types of developmental regulators in mammalian cells, and the role of PRC2 in adipogenesis, remain unclear. Here we show PRC2 and its H3K27 methyltransferase activity are required for adipogenesis. PRC2 directly represses Wnt1, 6, 10a and 10b genes in preadipocytes and during adipogenesis. Deletion of the enzymatic Ezh2 subunit of PRC2 eliminates H3K27me3 on Wnt promoters and de-represses Wnt expression, which leads to activation of Wnt/b-catenin signaling and inhibition of adipogenesis. Ectopic expression of the wild type Ezh2, but not the enzymatically inactive F667I mutant, prevents the loss of H3K27me3 and the defects in adipogenesis in Ezh2-/- preadipocytes. The adipogenesis defects in Ezh2-/- cells can be rescued by expression of adipogenic transcription factors PPARa, C/EBPb, or inhibitors of Wnt/b-catenin signaling. Interestingly, Ezh2-/- cells show marked increase of H3K27 acetylation globally as well as on Wnt promoters. These results indicate that H3K27 methyltransferase PRC2 directly represses Wnt genes to facilitate adipogenesis, and suggest that acetylation and trimethylation on H3K27 play opposing roles in regulating Wnt expression.
2010-03-19 | GSE20054 | GEO
Project description:The Polycomb Group proteins foster gene repression profiles required for proper development and unimpaired adulthood, and comprise the components of the PRC2 complex including the histone H3 lysine 27 (H3K27) methyltransferase Ezh2. How mammalian PRC2 accesses chromatin is unclear. We find that Jarid2 associates with PRC2 and stimulates its enzymatic activity in vitro. Jarid2 contains a Jumonji C domain, but is devoid of detectable histone demethylase activity. Instead, its artificial recruitment to a promoter in vivo resulted in co-recruitment of PRC2 with resultant increased levels of H3K27me2/3. Jarid2 co-localizes with Ezh2 and MTF2, a homologue of Drosophila Pcl, at endogenous genes in ES cells. Jarid2 can itself bind DNA and its recruitment in ES cells is interdependent with that of PRC2 as Jarid2 knockdown reduced PRC2 at its target promoters, and ES cells devoid of the PRC2 component EED are deficient in Jarid2 promoter access. In addition to the well-documented defects in embryonic viability upon down-regulation of Jarid2, ES cell differentiation is impaired, as is Oct4 silencing. Examination of two factors in ES cells
2010-01-01 | E-GEOD-19708 | biostudies-arrayexpress
Project description:We studied transcriptional changes by Affymetrix human microarrays in 2 DLBCL cell lines as a result of shRNA mediated knockdown of EZH2. In eukaryotes, epigenetic post-translational modification of histones is critical for regulation of chromatin structure and gene expression. EZH2 is the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) and is responsible for repressing target gene expression through methylation of histone H3 on lysine 27 (H3K27). Over-expression of EZH2 is implicated in tumorigenesis and correlates with poor prognosis in multiple tumor types. Recent reports have identified somatic heterozygous mutations of Y641 and A677 residues within the catalytic SET domain of EZH2 in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). The Y641 residue is the most frequently mutated residue, with 22% of GCB (Germinal Cell B-cell) DLBCL and FL harboring mutations at this site. These lymphomas exhibit increased H3K27 tri-methylation (H3K27me3) due to altered substrate preferences of the mutant enzymes. However, it is unknown whether direct inhibition of EZH2 methyltransferase activity alone will be effective in treating lymphomas carrying activating EZH2 mutations. Herein, we demonstrate that GSK126, a potent, highly-selective, SAM-competitive, small molecule inhibitor of EZH2 methyltransferase activity, decreases global H3K27me3 levels and reactivates silenced PRC2 target genes. GSK126 effectively inhibits the proliferation of EZH2 mutant DLBCL cell lines and dramatically inhibits the growth of EZH2 mutant DLBCL xenografts in mice. Together, these data demonstrate that pharmacological inhibition of EZH2 activity may provide a promising treatment for EZH2 mutant lymphoma. Pfeiffer and KARPAS-422 cells were treated with either shRNA targeting EZH2 (shEZH2) or a non targeting control (shNTC) for 10 days.
2012-10-12 | E-GEOD-41239 | biostudies-arrayexpress
Project description:Trimethylation on H3K27 (H3K27me3) mediated by Polycomb repressive complex 2 (PRC2) has been linked to embryonic stem cell (ESC) identity and pluripotency. EZH2, the catalytic subunit of PRC2, has been reported as the sole histone methyltransferase that methylates H3K27 and mediates transcriptional silencing. Analysis of Ezh2(-/-) ESCs suggests existence of an additional enzyme(s) catalyzing H3K27 methylation. We have identified EZH1, a homolog of EZH2 that is physically present in a noncanonical PRC2 complex, as an H3K27 methyltransferase in vivo and in vitro. EZH1 colocalizes with the H3K27me3 mark on chromatin and preferentially preserves this mark on development-related genes in Ezh2(-/-) ESCs. Depletion of Ezh1 in cells lacking Ezh2 abolishes residual methylation on H3K27 and derepresses H3K27me3 target genes, demonstrating a role of EZH1 in safeguarding ESC identity. Ezh1 partially complements Ezh2 in executing pluripotency during ESC differentiation, suggesting that cell-fate transitions require epigenetic specificity.
2009-03-25 | GSE15388 | GEO
Project description:EZH2 is a catalytic component of polycomb repressive complex 2 (PRC2), which contributes to aggressiveness in many types of cancers. Targeting EZH2/PRC2 has been challenged and now some inhibitors are under clinical trials for cancer treatments. Interestingly, anti-tumor effects of EZH2 is not always depend on H3K27 methyltransferase activity. In order to identify novel inhibitors against EZH2/PRC2, we established a chemical screening system based on measurement of reactivation of promoter activity, which is intrinsically silenced by EZH2/PRC2. We screened more than 300,000 small chemicals and identified 85 chemicals. After validation of reactivation of EZH2/PRC2 target genes, we identified chemical NPD13668 as a potential inhibitor of EZH2/PRC2 activity. To evaluate NPD13668 effect, we analysed whole genome expression change by using SurePrint G3 Human GE 8×60K array slides (G4851B, Agilent Technologies).
2019-02-01 | GSE122997 | GEO
Project description:Multiple myeloma (MM) is the second most common hematological malignancy with poor prognosis. Enhancer of zeste homolog 2 (EZH2) is the enzymatic subunit of polycomb repressive complex 2 (PRC2), which catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) for transcriptional repression. EZH2 have been implicated in numerous hematological malignancies, including MM. However, noncanonical functions of EZH2 in MM tumorigenesis are not well understood. Here, we uncovered a noncanonical function of EZH2 in MM malignancy. In addition to the PRC2-mediated and H3K27me3-dependent canonical function, EZH2 interacts with cMyc and co-localizes with gene activation markers, promoting MM tumorigenesis in a PRC2- and H3K27me3-independent manner. Both canonical EZH2-PRC2 and noncanonical EZH2-cMyc complexes can be effectively depleted in MM cells by MS177, an EZH2 degrader we reported previously, leading to profound activation of EZH2-PRC2-associated genes and suppression of EZH2-cMyc oncogenic nodes. The MS177-induced degradation of both canonical EZH2-PRC2 and noncanonical EZH2-cMyc complexes also reactivated immune response genes in MM cells. Phenotypically, targeting of EZH2’s both canonical and noncanonical functions by MS177 effectively suppressed the proliferation of MM cells both in vitro and in vivo. Collectively, this study uncovers a new noncanonical function of EZH2 in MM tumorigenesis and provides a novel therapeutic strategy, pharmacological degradation of EZH2, for treating EZH2-dependent MM.
2023-01-25 | GSE214668 | GEO
Project description:Multiple myeloma (MM) is the second most common hematological malignancy with poor prognosis. Enhancer of zeste homolog 2 (EZH2) is the enzymatic subunit of polycomb repressive complex 2 (PRC2), which catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) for transcriptional repression. EZH2 have been implicated in numerous hematological malignancies, including MM. However, noncanonical functions of EZH2 in MM tumorigenesis are not well understood. Here, we uncovered a noncanonical function of EZH2 in MM malignancy. In addition to the PRC2-mediated and H3K27me3-dependent canonical function, EZH2 interacts with cMyc and co-localizes with gene activation markers, promoting MM tumorigenesis in a PRC2- and H3K27me3-independent manner. Both canonical EZH2-PRC2 and noncanonical EZH2-cMyc complexes can be effectively depleted in MM cells by MS177, an EZH2 degrader we reported previously, leading to profound activation of EZH2-PRC2-associated genes and suppression of EZH2-cMyc oncogenic nodes. The MS177-induced degradation of both canonical EZH2-PRC2 and noncanonical EZH2-cMyc complexes also reactivated immune response genes in MM cells. Phenotypically, targeting of EZH2’s both canonical and noncanonical functions by MS177 effectively suppressed the proliferation of MM cells both in vitro and in vivo. Collectively, this study uncovers a new noncanonical function of EZH2 in MM tumorigenesis and provides a novel therapeutic strategy, pharmacological degradation of EZH2, for treating EZH2-dependent MM.
2023-01-25 | GSE214667 | GEO
Project description:Canonically, Enhancer of Zeste Homolog 2 (EZH2) serves as the main catalytic subunit of Polycomb Repressive Complex 2 (PRC2), mediating H3K27me3 deposition and transcriptional repression. Here, we report that, in MLL1-rearranged acute leukemias, EZH2 has additional noncanonical functions by binding the oncoprotein cMyc at its non-PRC2 target sites where EZH2 uses a hidden transactivation domain (TAD) for (co)activator recruitment and gene activation. Canonical (EZH2:PRC2) and noncanonical (EZH2-TAD:cMyc) activities of EZH2 both promote oncogenesis, thus explaining the slow and often ineffective antitumor effects by current catalytic inhibitors of EZH2. To suppress EZH2’s multifaceted activities in cancer, we employed the Proteolysis Targeting Chimera (PROTAC) technology and developed a small-molecule degrader, MS177, which achieved effective, on-target depletion of EZH2 and its interacting partners (i.e., both canonical EZH2:PRC2 and noncanonical EZH2:cMyc complexes). MS177-mediated onco-target degradation is cereblon- and proteasome-dependent. Compared to EZH2 enzymatic inhibitors, MS177 is fast-acting and much more potent in suppressing cancer growth. Overall, this study reveals noncanonical oncogenic functions of EZH2, and presents a highly effective PROTAC for targeting EZH2’s multifaceted tumorigenic actions and a novel and attractive therapeutic strategy for the treatment of EZH2-depdendent cancers.
2021-12-29 | GSE150823 | GEO