EZH2 is a mediator of EWS-FLI1 driven tumor growth blocking endothelial and neuro-ectodermal differentiation
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE12692 | GEO | 2008/10/01
SECONDARY ACCESSION(S): PRJNA112701
REPOSITORIES: GEO
Similar Datasets
Project description:Ewing Tumors (ET) are highly malignant tumors, localized in bone or soft tissue and are molecularly defined by ews/ets translocations. We identified histone methyl-transferase Enhancer of Zeste, Drosophila, Homolog 2 (EZH2) to be increased in ET. EZH2âs suppressive activity maintains stemness in normal and malignant cells. Here we found EZH2 to be upregulated by the pathognomonic fusion oncogene EWS-FLI1 in ET and mesenchymal stem cells. Downregulation of EZH2 by RNA interference in ET suppressed oncogenic transformation by inhibiting clonogenicity in vitro. Similarly, tumor development and metastasis in immunodeficient Rag2-/-γC-/- mice was suppressed. EZH2-mediated gene silencing was shown to be dependent on histone deacetylase (HDAC) activity. Subsequent microarray analysis of EZH2 knock down, HDAC-inhibitor treatment and confirmation in independent assays revealed an undifferentiated phenotype maintained by EZH2 in ET. Downregulation of EZH2 decreased histone H3 lysine 27 trimethylation (H3K27me3) at target loci. EZH2 regulated stemness genes such as nerve growth factor receptor (NGFR) as well as genes involved in neuroectodermal differentiation (EMP1, EPHB2, GFAP, GAP43). These data suggest that EZH2 might play a central role in Ewing Tumor pathology shaping the oncogenicity and stem cell phenotype of this tumor presumably by epigenetic regulation. Experiment Overall Design: A673 cells were treated for 24 hours either with 100 nM Trichostatin A (TSA) or 0.01% DMSO. In siRNA experiments with ezh2 specific siRNA A673 cells were resuspended in medium containing 5 nM siRNA and transfection reagent and incubated for 48 hours. RNA from cells under such treatment was isolated with Trizol and subjected to microarray analysis onto human U133A microarray following the Affymetrix protocol.
2008-10-26 | E-GEOD-12692 | biostudies-arrayexpress
Project description:Chromatin modifications are increasingly recognized as a key mechanism in cancer. The histone methyl-transferase Enhancer of Zeste, Drosophila, Homolog 2 (EZH2) is the enzymatic subunit of the polycomb PRC2 complex and methylates histone H3K27, thereby, mediating gene silencing. Down-regulation of EZH2 by RNA interference in ET suppressed oncogenic transformation, tumor development and metastasis in a respective mouse model. Further microarray analysis of EZH2 knock down, or functionally linked HDAC-inhibitor treatment revealed an undifferentiated reversible phenotype in ET maintained by EZH2. EZH2 suppression resulted in a generalized loss of H3K27me3 as well as an increase in H3 acetylation levels. In addition, ChIP-Chip assays for H3K27me3 identified genes that had specifically lost H3K27me3 upon EZH2 silencing. These findings suggested that stemness features are preserved via epigenetic mechanisms. Taken together, the genetic EWS-Fli1 translocation is intimately linked to global and gene specific epigenetic alterations in ET biology. EZH2 mediates neuroectodermal and endothelial embryonal tumor stem cell growth and metastasic spread induced by a translocation derived chimeric transcription factor. Keywords: PNET, Ewing Tumor Epigenetic regulation A673 transiently transfected with siRNA-EZH2 and siRNA-scrambled were harvested and Chromatin-IPs of H3K27me3 or H3 followed by microarray hybridisation were carried out. For detailed procedures see Burdach et al. Epigenetic Maintenance of Stemness and Malignancy in Peripheral Neuroectodermal Tumors by EZH2.
2010-05-18 | E-GEOD-15890 | biostudies-arrayexpress
Project description:Chromatin modifications are increasingly recognized as a key mechanism in cancer. The histone methyl-transferase Enhancer of Zeste, Drosophila, Homolog 2 (EZH2) is the enzymatic subunit of the polycomb PRC2 complex and methylates histone H3K27, thereby, mediating gene silencing. Down-regulation of EZH2 by RNA interference in ET suppressed oncogenic transformation, tumor development and metastasis in a respective mouse model. Further microarray analysis of EZH2 knock down, or functionally linked HDAC-inhibitor treatment revealed an undifferentiated reversible phenotype in ET maintained by EZH2. EZH2 suppression resulted in a generalized loss of H3K27me3 as well as an increase in H3 acetylation levels. In addition, ChIP-Chip assays for H3K27me3 identified genes that had specifically lost H3K27me3 upon EZH2 silencing. These findings suggested that stemness features are preserved via epigenetic mechanisms. Taken together, the genetic EWS-Fli1 translocation is intimately linked to global and gene specific epigenetic alterations in ET biology. EZH2 mediates neuroectodermal and endothelial embryonal tumor stem cell growth and metastasic spread induced by a translocation derived chimeric transcription factor. Keywords: PNET, Ewing Tumor Epigenetic regulation
2009-06-02 | GSE15890 | GEO
Project description:We found the PRC2 component EZH2 to be upregulated by the pathognomonic fusion oncogene EWS-FLI1 in Ewing tumors and mesenchymal stem cells (Richter GH et al., Proc Natl Acad Sci U S A. 2009;106:5324-9). Downregulation of EZH2 by RNA interference in Ewing tumor cell lines suppressed oncogenic transformation in vitro and in vivo. These data suggest that EZH2 might play a central role in Ewing Tumor pathology. RNA from tumor samples was isolated with Trizol and subjected to microarray analysis using HG_U133A microarrays following the Affymetrix protocol. Ewing tumors vs. neuroblastoma controls
2009-04-29 | E-GEOD-15757 | biostudies-arrayexpress
Project description:Background: Ewing sarcoma (EwS) are characterized by oncogenic chimeric EWS-ETS proteins. EZH2 is upregulated via predominant EWS-FLI1 in EwS. RNAi of EZH2 revealed an EZH2-maintained, undifferentiated, stemness phenotype. Herein, microarray analysis demonstrated that treatment with HDAC inhibitors (HDACi) entinostat or TSA resulted in the induction of a similar pattern of differentiation genes as observed after EZH2 RNAi. This indicates that EZH2-containing PRC2 complexes may serve as a building block of class I HDAC activity in EwS. Methods: The role of class I HDACs was determined using different inhibitors including TSA, romidepsin (FK228), entinostat (MS-275) and PCI-34051 as well as CRISPR/Cas9 class I HDAC knock outs and HDAC RNAi. To analyze resulting changes microarray and gene set enrichment analysis (GSEA), qRT-PCR, western blotting, Co-IP, proliferation, apoptosis, differentiation, invasion assays and xenograft-mouse models were used. Results: Class I HDACs are constitutively expressed in EwS. They seem regulated via EWS-FLI1. Interestingly, patients with high levels of individual class I HDAC expression show decreased overall survival. CRISPR/Cas9 class I HDAC knock out of individual HDACs such as HDAC1 and HDAC2 inhibited growth, invasiveness, and blocked local tumor growth in xenograft mice. Microarray and GSEA analysis demonstrated that treatment with individual HDAC inhibitors (HDACi) blocked an EWS-FLI1 specific expression profile, while entinostat in addition suppressed metastasis relevant genes. EwS cells demonstrated increased susceptibility to treatment with first line chemotherapeutics including doxorubicin in the presence of HDACi. Furthermore, HDACi treatment mimicked RNAi of EZH2 in EwS. Treated cells showed diminished growth capacity, but an increased endothelial as well as neuronal differentiation ability. HDACi synergizes with EED inhibitor (EEDi) in vitro and together inhibited tumor growth in xenograft mice. Co-IP experiments identified HDAC class I family members as part of a regulatory complex together with PRC2. Conclusion: Class I HDAC proteins seem to be important mediators of the pathognomonic EWS-ETS-mediated transcription program in EwS and in combination therapy, co-treatment with HDACi are interesting new treatment opportunities for this malignant disease.
2021-10-20 | GSE162788 | GEO
Project description:Background: Ewing sarcoma (EwS) are characterized by oncogenic chimeric EWS-ETS proteins. EZH2 is upregulated via predominant EWS-FLI1 in EwS. RNAi of EZH2 revealed an EZH2-maintained, undifferentiated, stemness phenotype. Herein, microarray analysis demonstrated that treatment with HDAC inhibitors (HDACi) entinostat or TSA resulted in the induction of a similar pattern of differentiation genes as observed after EZH2 RNAi. This indicates that EZH2-containing PRC2 complexes may serve as a building block of class I HDAC activity in EwS. Methods: The role of class I HDACs was determined using different inhibitors including TSA, romidepsin (FK228), entinostat (MS-275) and PCI-34051 as well as CRISPR/Cas9 class I HDAC knock outs and HDAC RNAi. To analyze resulting changes microarray and gene set enrichment analysis (GSEA), qRT-PCR, western blotting, Co-IP, proliferation, apoptosis, differentiation, invasion assays and xenograft-mouse models were used. Results: Class I HDACs are constitutively expressed in EwS. They seem regulated via EWS-FLI1. Interestingly, patients with high levels of individual class I HDAC expression show decreased overall survival. CRISPR/Cas9 class I HDAC knock out of individual HDACs such as HDAC1 and HDAC2 inhibited growth, invasiveness, and blocked local tumor growth in xenograft mice. Microarray and GSEA analysis demonstrated that treatment with individual HDAC inhibitors (HDACi) blocked an EWS-FLI1 specific expression profile, while entinostat in addition suppressed metastasis relevant genes. EwS cells demonstrated increased susceptibility to treatment with first line chemotherapeutics including doxorubicin in the presence of HDACi. Furthermore, HDACi treatment mimicked RNAi of EZH2 in EwS. Treated cells showed diminished growth capacity, but an increased endothelial as well as neuronal differentiation ability. HDACi synergizes with EED inhibitor (EEDi) in vitro and together inhibited tumor growth in xenograft mice. Co-IP experiments identified HDAC class I family members as part of a regulatory complex together with PRC2. Conclusion: Class I HDAC proteins seem to be important mediators of the pathognomonic EWS-ETS-mediated transcription program in EwS and in combination therapy, co-treatment with HDACi are interesting new treatment opportunities for this malignant disease.
2021-10-20 | GSE162786 | GEO
Project description:Background: Ewing sarcoma (EwS) are characterized by oncogenic chimeric EWS-ETS proteins. EZH2 is upregulated via predominant EWS-FLI1 in EwS. RNAi of EZH2 revealed an EZH2-maintained, undifferentiated, stemness phenotype. Herein, microarray analysis demonstrated that treatment with HDAC inhibitors (HDACi) entinostat or TSA resulted in the induction of a similar pattern of differentiation genes as observed after EZH2 RNAi. This indicates that EZH2-containing PRC2 complexes may serve as a building block of class I HDAC activity in EwS. Methods: The role of class I HDACs was determined using different inhibitors including TSA, romidepsin (FK228), entinostat (MS-275) and PCI-34051 as well as CRISPR/Cas9 class I HDAC knock outs and HDAC RNAi. To analyze resulting changes microarray and gene set enrichment analysis (GSEA), qRT-PCR, western blotting, Co-IP, proliferation, apoptosis, differentiation, invasion assays and xenograft-mouse models were used. Results: Class I HDACs are constitutively expressed in EwS. They seem regulated via EWS-FLI1. Interestingly, patients with high levels of individual class I HDAC expression show decreased overall survival. CRISPR/Cas9 class I HDAC knock out of individual HDACs such as HDAC1 and HDAC2 inhibited growth, invasiveness, and blocked local tumor growth in xenograft mice. Microarray and GSEA analysis demonstrated that treatment with individual HDAC inhibitors (HDACi) blocked an EWS-FLI1 specific expression profile, while entinostat in addition suppressed metastasis relevant genes. EwS cells demonstrated increased susceptibility to treatment with first line chemotherapeutics including doxorubicin in the presence of HDACi. Furthermore, HDACi treatment mimicked RNAi of EZH2 in EwS. Treated cells showed diminished growth capacity, but an increased endothelial as well as neuronal differentiation ability. HDACi synergizes with EED inhibitor (EEDi) in vitro and together inhibited tumor growth in xenograft mice. Co-IP experiments identified HDAC class I family members as part of a regulatory complex together with PRC2. Conclusion: Class I HDAC proteins seem to be important mediators of the pathognomonic EWS-ETS-mediated transcription program in EwS and in combination therapy, co-treatment with HDACi are interesting new treatment opportunities for this malignant disease.
2021-10-20 | GSE162785 | GEO
Project description:We found the PRC2 component EZH2 to be upregulated by the pathognomonic fusion oncogene EWS-FLI1 in Ewing tumors and mesenchymal stem cells (Richter GH et al., Proc Natl Acad Sci U S A. 2009;106:5324-9). Downregulation of EZH2 by RNA interference in Ewing tumor cell lines suppressed oncogenic transformation in vitro and in vivo. These data suggest that EZH2 might play a central role in Ewing Tumor pathology.
2009-04-29 | GSE15757 | GEO
Project description:The cellular origin of Ewing tumor (ET), a tumor of bone or soft tissues characterized by specific fusions between EWS and ETS genes, is highly debated. Through gene expression analysis comparing ETs with a variety of normal tissues, we show that the profiles of different EWS-FLI1-silenced Ewing cell lines converge toward that of mesenchymal stem cells (MSC). Moreover, upon EWS-FLI1 silencing, two different Ewing cell lines can differentiate along the adipogenic lineage when incubated in appropriate differentiation cocktails. In addition, Ewing cells can also differentiate along the osteogenic lineage upon long-term inhibition of EWS-FLI1. These in silico and experimental data strongly suggest that the inhibition of EWS-FLI1 may allow Ewing cells to recover the phenotype of their MSC progenitor. Experiment Overall Design: Ewing tumors and EWS-FLI-1 inhibited cell lines were profiled on Affymetrix U133A (GPL96) arrays.
2008-06-15 | E-GEOD-7007 | biostudies-arrayexpress
Project description:The cellular origin of Ewing tumor (ET), a tumor of bone or soft tissues characterized by specific fusions between EWS and ETS genes, is highly debated. Through gene expression analysis comparing ETs with a variety of normal tissues, we show that the profiles of different EWS-FLI1-silenced Ewing cell lines converge toward that of mesenchymal stem cells (MSC). Moreover, upon EWS-FLI1 silencing, two different Ewing cell lines can differentiate along the adipogenic lineage when incubated in appropriate differentiation cocktails. In addition, Ewing cells can also differentiate along the osteogenic lineage upon long-term inhibition of EWS-FLI1. These in silico and experimental data strongly suggest that the inhibition of EWS-FLI1 may allow Ewing cells to recover the phenotype of their MSC progenitor. Keywords: expression analysis
2007-02-14 | GSE7007 | GEO