PRC2 in Ewing tumors
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE15757 | GEO | 2009/04/29
SECONDARY ACCESSION(S): PRJNA116785
REPOSITORIES: GEO
Similar Datasets
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:Ewing sarcoma (EWS) is a malignant pediatric bone cancer. Most Ewing sarcomas are driven by EWS-FLI1 oncogenic transcription factor that plays roles in transcriptional regulation, DNA damage response, cell cycle checkpoint control, and alternative splicing. USP1, a deubiquitylase which regulates DNA damage and replication stress responses, is overexpressed at both the mRNA and protein levels in EWS cell lines compared to human mesenchymal stem cells, the EWS cell of origin. The functional significance of high USP1 expression in Ewing sarcoma is not known. Here, we identify USP1 as a transcriptional target of EWS-FLI1 and a key regulator of EWS cell survival. We show that EWS-FLI1 knockdown decreases USP1 mRNA and protein levels. ChIP and ChIP-seq analyses show EWS-FLI1 occupancy on the USP1 promoter. Importantly, USP1 knockdown or inhibition arrests EWS cell growth and induces cell death by apoptosis. We observe destabilization of Survivin (also known as BIRC5 or IAP4) and activation of caspases-3 and -7 following USP1 knockdown or inhibition in the absence of external DNA damage stimuli. Notably, EWS cells display hypersensitivity to combinatorial treatment of doxorubicin or etoposide, EWS standard of care drugs, and USP1 inhibitor compared to single agents alone. Together, our study demonstrates that USP1 is regulated by EWS-FLI1, the USP1-Survivin axis promotes EWS cell survival, and USP1 inhibition sensitizes EWS cells to standard of care chemotherapy.
2024-01-26 | PXD041033 | Pride
Project description:Ewing sarcoma is characterized by pathognomonic translocations fusing most frequently EWSR1 with FLI1 (EF1). In addition, Ewing sarcoma can also display alterations in STAG2, TP53 and CDKN2A (SPC). Starting from Ewing sarcoma derived human mesenchymal stem cells (MSCpat), we recapitulated this translocation and SPC alterations using a CRISPR/cas9 approach and generated a bona fide Ewing sarcoma model (EWIma1) displaying transcriptomic and epigenetic hallmarks of EwS.
2021-09-08 | GSE150777 | GEO
Project description:Ewing sarcoma is characterized by pathognomonic translocations fusing most frequently EWSR1 with FLI1 (EF1). In addition, Ewing sarcoma can also display alterations in STAG2, TP53 and CDKN2A (SPC). Starting from Ewing sarcoma derived human mesenchymal stem cells (MSCpat), we recapitulated this translocation and SPC alterations using a CRISPR/cas9 approach and generated a bona fide Ewing sarcoma model (EWIma1) displaying transcriptomic and epigenetic hallmarks of EwS.
2021-08-18 | GSE150776 | GEO
Project description:Ewing sarcoma (EwS) is an adolescent and young adult sarcoma characterized by chromosome translocations between members of the FET family of RNA binding proteins and members of the ETS family of transcription factors, the most frequent fusion being EWS-FLI1. EWS-FLI1 acts as a pioneer factor, creating de novo enhancers and activating genes located in the vicinity of EWS-FLI1-bound microsatellite sequences. recent results from our lab indicate that EWS-FLI1, which activates transcription through binding to the DNA at specific sites, can generate fully novel, unconventional transcription units in regions of the genome that are fully quiescent in normal cells (manuscript in preparation). The hypothesis of the project is that the open reading frames (ORFs) of these transcripts may encode peptides presented at the cell surface by HLA class I molecules and hence be recognized as non-self by the immune system. The aim of this study is to detect Ewing-specific neo-peptides/proteins using proteomics approach.
2022-05-12 | PXD027309 | Pride
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. EZH2’s 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.
2008-10-01 | GSE12692 | GEO
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: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: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