ABSTRACT: Enhancer of Zeste Homolog 2 (EZH2) is a histone methyltransferase that catalyzes the trimethylation of histone H3 lysine 27 (H3K27me3). EZH2 expression is significantly upregulated in MPNST. In our study, we investigated the function of EZH2 and the molecular mechanisms that are regulated by EZH2 in MPNST pathogenesis. Our findings enhance the knowledge of EZH2’s function and biology, and have the potential to provide a novel therapeutic approach for MPNST patients in the clinic.
Project description:Enhancer of Zeste Homolog 2 (EZH2) is a histone methyltransferase that catalyzes the trimethylation of histone H3 lysine 27 (H3K27me3). EZH2 expression is significantly upregulated in MPNST. In our study, we investigated the function of EZH2 and the molecular mechanisms that are regulated by EZH2 in MPNST pathogenesis. Our findings enhance the knowledge of EZH2’s function and biology, and have the potential to provide a novel therapeutic approach for MPNST patients in the clinic. An EZH2 knockdown experiment was carried out in MPNST cells. There are one control and one siEZH2 samples for three cell lines (724,462,26T) and two repeats for each cell line, so in total there are 8 samples. Two group comparison Two group comparison
Project description:Enhancer of Zeste Homolog 2 (EZH2) is a histone methyltransferase that catalyzes the trimethylation of histone H3 lysine 27 (H3K27me3). EZH2 expression is significantly upregulated in MPNST. In our study, we investigated the function of EZH2 and the molecular mechanisms that are regulated by EZH2 in MPNST pathogenesis. Our findings enhance the knowledge of EZH2’s function and biology, and have the potential to provide a novel therapeutic approach for MPNST patients in the clinic. An EZH2 knockdown experiment was carried out in MPNST cells. There are one control and one siEZH2 samples for two cell lines (724 and 462) and two repeats for each cell line, so in total there are 8 samples. Two group comparison
Project description:Enhancer of Zeste Homolog 2 (EZH2) is a histone methyltransferase that catalyzes the trimethylation of histone H3 lysine 27 (H3K27me3). EZH2 expression is significantly upregulated in MPNST. In our study, we investigated the function of EZH2 and the molecular mechanisms that are regulated by EZH2 in MPNST pathogenesis. Our findings enhance the knowledge of EZH2’s function and biology, and have the potential to provide a novel therapeutic approach for MPNST patients in the clinic.
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.
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.
Project description:Transcriptional analysis of genes in SKBr3 cells. Enhancer of zeste homolog 2 (EZH2) is a mammalian histone methyltransferase that contributes to the epigenetic silencing of target genes and regulates the survival and metastasis of cancer cells. EZH2 is overexpressed in aggressive solid tumors by mechanisms that remain unclear. Here we show that the expression and function of EZH2 in cancer cell lines are inhibited by microRNA-101 (miR-101).
Project description:The symptoms of ataxia-telangiectasia (A-T) include a progressive neurodegeneration caused by ATM protein deficiency. We previously found that nuclear accumulation of histone deacetylase-4, HDAC4, contributes to this degeneration; we now report that increased histone H3K27 trimethylation (H3K27me3) mediated by polycomb repressive complex 2 (PRC2) also plays an important role in the A-T phenotype. Enhancer of zeste homolog 2 (EZH2), a core catalytic component of PRC2, is identified as a new ATM kinase target, and its S734 phosphorylation reduces protein stability. Thus, PRC2 formation is elevated along with H3K27me3in ATM deficiency. ChIP-sequencing shows a significant increase in H3K27me3 ‘marks’ and a dramatic shift in their location. The change of H3K27me3 chromatin-binding pattern is directly related to cell cycle re-entry and cell death of ATM-deficient neurons. Lentiviral knockdown of EZH2 rescues Purkinje cell degeneration and behavioral abnormalities in Atm / mice, demonstrating that EZH2-mediated H3K27me3 is another key factor in A-T neurodegeneration. Two samples each were run of brain total RNA from Atm+/+ and Atm-/- mice.
Project description:The Polycomb group (PcG) protein enhancer of zeste homolog 2 (EZH2) plays an essential role in histone methylation-mediated epigenetic gene silencing. We demonstrate that under physiological conditions, cyclin-dependent kinase 1 (CDK1) and 2 (CDK2) bind to and phosphorylate EZH2 at threonine 350 (T350) in an evolutionally conserved motif. T350 phosphorylation is required for EZH2 function in silencing of genes that promote differentiation and inhibit proliferation and migration. Blockage of T350 phosphorylation by generating a T350A mutation largely diminishes the global effect of EZH2 on gene silencing. Four experiments have been designed. BJ cells were transfected with si-Control, si-EZH2, si-EZH2 plus RNAi resistant lentivirus expressed EZH2, or si-EZH2 plus RNAi resistant lentivirus expressed T350A mutant for 60 hours. Each experiment was triplicated.
Project description:Enhancer of zeste homolog 2 (Ezh2) is the methyltransferase component of the Polycomb Repressive Complex 2 (PRC2), which is critical for trimethylation of histone 3 at lysine 27 (H3K27me3) and results in gene repression. Mutations in EZH2 and dysregulation of H3K27me3 can lead to neurodevelopmental abnormalities such as Weaver Syndrome and ataxia-telangiectasia. During cortical neurogenesis, H3K27me3 is a critical epigenetic modification that regulates cellular maturation rate, and in turn, determines when precursor cells exit the cell cycle. Loss of function studies reveal that Ezh2 plays a critical role in epigenetic regulation of neuronal fate and maturation in some brain regions, but a role for Ezh2 in forebrain GABAergic interneurons has not been explored. Here, we removed Ezh2 from the medial ganglionic eminence (MGE) to study its role in interneuron development.
Project description:The Polycomb group (PcG) protein enhancer of zeste homolog 2 (EZH2) plays an essential role in histone methylation-mediated epigenetic gene silencing. We demonstrate that under physiological conditions, cyclin-dependent kinase 1 (CDK1) and 2 (CDK2) bind to and phosphorylate EZH2 at threonine 350 (T350) in an evolutionally conserved motif. T350 phosphorylation is required for EZH2 function in silencing of genes that promote differentiation and inhibit proliferation and migration. Blockage of T350 phosphorylation by generating a T350A mutation largely diminishes the global effect of EZH2 on gene silencing. Seven experiments have been designed. LNCaP cells were transfected with si-Control, si-EZH2, si-EZH2 plus RNAi resistant EZH2 plasmid, or si-EZH2 plus RNAi resistant T350A mutated EZH2 plsamid for 60 hours, or treated with DMSO, 5 uM TSA, or 10 uM Roscovitine for 24 hours. Two replicates per experiment.