The effects of chimeric EWS/ETS protein in human mesenchymal progenitor cells (MPCs).
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE8665 | GEO | 2007/08/03
SECONDARY ACCESSION(S): PRJNA101871
REPOSITORIES: GEO
Similar Datasets
Project description:We have examined the biological effect of EWS/ETS in human MPCs using UET-13 cells that are obtained by prolonging the lifespan of human bone marrow stromal cells using the retroviral transgenes hTERT and E7. By exploiting tetracycline-inducible systems for expressing EWS/ETS (EWS/FLI1 and EWS/ERG), we investigated candidates for genes whose expression is regulated by EWS/ETS in human MPCs. Experiment Overall Design: A change of expression profiles in the presence of EWS/ETS using Affymetrix HG-U133 Plus 2.0 (GPL570).
2008-06-16 | E-GEOD-8665 | biostudies-arrayexpress
Project description:The pathognomonic EWS/ETS fusion transcription factors drive Ewing sarcoma (EWS) by orchestrating an oncogenic transcription program. Therapeutic targeting of EWS/ETS has not been successful; therefore identifying mediators of the EWS/ETS function could offer new therapeutic targets. Here we describe the dependency of chromatin reader BET bromodomain proteins in EWS/ETS driven transcription and investigate the potential of BET inhibitors in treating this lethal cancer. Similar to EWS/ETS fusions, knockdown of BET proteins BRD2/3/4 severely impaired the oncogenic phenotype of EWS cells. Notably, EWS/FLI1 and EWS/ERG was found to be in a transcriptional complex consisting of BRD4. RNA-Seq analysis upon BRD4 knockdown or its pharmacologic inhibition by the BET inhibitor JQ1 revealed an attenuated EWS/ETS transcriptional signature. In contrast to other reports, JQ1 reduced proliferation, and induced apoptosis through MYC-independent mechanism without affecting EWS/ETS protein levels, which was further confirmed by depleting BET proteins using PROTAC-BET degrader (BETd). Interestingly, polycomb repressive complex 2 (PRC2) associated factor PHF19 was downregulated by JQ1/BETd or BRD4 knockdown in multiple EWS cells. ChIP-seq analysis revealed occupancy of EWS/FLI1 at a distal regulatory element of PHF19 and its subsequent knockdown resulted in downregulation of PHF19 expression. Furthermore, deletion of PHF19 by CRISPR-Cas9 system lead to a decreased tumorigenic phenotype and increased sensitivity to JQ1. Importantly, PHF19 expression was associated with worse prognosis of Ewing sarcoma patients. In vivo, JQ1 demonstrated anti-tumor efficacy in multiple mouse xenograft models of EWS. Together, these results indicate that EWS/ETS require BET epigenetic reader proteins for its transcriptional program including PHF19 expression, which can be mitigated by BET inhibitors. Moreover, this study provides a clear rationale for the clinical utility of BET inhibitors in treating Ewing sarcoma.
2018-06-19 | GSE113604 | GEO
Project description:Ewing sarcomas (ES) are highly malignant, osteolytic bone or soft tissue tumors, which are characterized by early metastasis into lung and bone. Genetically, ES are defined by balanced chromosomal EWS/ETS translocations, which give rise to chimeric proteins (EWS-ETS) that generate an oncogenic transcriptional program associated with altered epigenetic marks throughout the genome. By use of an inhibitor (JQ1) blocking BET bromodomain binding proteins (BRDs) we strikingly observed a strong down-regulation of the predominant EWS-ETS protein EWS/FLI1 in a dose dependent manner. Microarray analysis further revealed JQ1 treatment to block a typical ES associated expression program. The effect on this expression program could be mimicked by RNA interference with BRD3 or BRD4 expression, indicating that the EWS/FLI1 mediated expression profile is at least in part mediated via such epigenetic readers. Consequently, contact dependent and independent proliferation of different ES lines was strongly inhibited. Mechanistically, treatment of ES resulted in a partial arrest of the cell cycle as well as induction of apoptosis. Tumor development was suppressed dose dependently in a xeno-transplant model in immune deficient mice, overall indicating that ES may be susceptible to treatment with epigenetic inhibitors blocking BET bromodomain activity and the associated pathognomonic EWS-ETS transcriptional program in ES. Ewing sarcoma cell lines A673 and TC-71 were treated for 48 hours with 2 microM JQ1 or DMSO control.
2015-12-08 | E-GEOD-72673 | biostudies-arrayexpress
Project description:Translocations of ETS transcription factors are driver mutations in diverse cancers. We investigated the genomic network of the ETS fusion EWS/FLI1 in Ewing's sarcoma (ESFT) as a model of ETS-driven tumorigenesis. ChIP-Seq and transcriptional analysis identified E2F3 as a principle co-factor of EWSFLI1 defining functionally distinct gene sets. While EWS/FLI1 binding independent of E2F3 predominantly associated with repressed differentiation genes, significant co-localization with E2F3 was discovered at proximal promoters of activated growth-related genes. Thus, EWS/FLI1 promotes oncogenesis by simultaneously perturbing differentiation state and augmenting the expression of genes co-regulated by E2F3. Integration of additional E2F3 and ERG localization data from prostate cancer containing TMPRSS2/ERG verified that the ETS-E2F module is also found in prostate cancer and may be of general relevance to ETS driven cancers. Timecourse with 6 timepoints of a doxicyclin inducible EWS-FLI1 knockdown in the A673 Ewing's Sarcoma celline
2013-07-01 | E-GEOD-27524 | biostudies-arrayexpress
Project description:Ewing sarcomas (ES) are highly malignant, osteolytic bone or soft tissue tumors, which are characterized by early metastasis into lung and bone. Genetically, ES are defined by balanced chromosomal EWS/ETS translocations, which give rise to chimeric proteins (EWS-ETS) that generate an oncogenic transcriptional program associated with altered epigenetic marks throughout the genome. By use of an inhibitor (JQ1) blocking BET bromodomain binding proteins (BRDs) we strikingly observed a strong down-regulation of the predominant EWS-ETS protein EWS/FLI1 in a dose dependent manner. Microarray analysis further revealed JQ1 treatment to block a typical ES associated expression program. The effect on this expression program could be mimicked by RNA interference with BRD3 or BRD4 expression, indicating that the EWS/FLI1 mediated expression profile is at least in part mediated via such epigenetic readers. Consequently, contact dependent and independent proliferation of different ES lines was strongly inhibited. Mechanistically, treatment of ES resulted in a partial arrest of the cell cycle as well as induction of apoptosis. Tumor development was suppressed dose dependently in a xeno-transplant model in immune deficient mice, overall indicating that ES may be susceptible to treatment with epigenetic inhibitors blocking BET bromodomain activity and the associated pathognomonic EWS-ETS transcriptional program in ES.
2015-12-08 | GSE72673 | GEO
Project description:Translocations of ETS transcription factors are driver mutations in diverse cancers. We investigated the genomic network of the ETS fusion EWS/FLI1 in Ewing's sarcoma (ESFT) as a model of ETS-driven tumorigenesis. ChIP-Seq and transcriptional analysis identified E2F3 as a principle co-factor of EWSFLI1 defining functionally distinct gene sets. While EWS/FLI1 binding independent of E2F3 predominantly associated with repressed differentiation genes, significant co-localization with E2F3 was discovered at proximal promoters of activated growth-related genes. Thus, EWS/FLI1 promotes oncogenesis by simultaneously perturbing differentiation state and augmenting the expression of genes co-regulated by E2F3. Integration of additional E2F3 and ERG localization data from prostate cancer containing TMPRSS2/ERG verified that the ETS-E2F module is also found in prostate cancer and may be of general relevance to ETS driven cancers.
2013-07-01 | GSE27524 | GEO
Project description:ERG activates prostate cancer specific gene expression program by recruiting RNA binding protein EWS to ETS-AP1 and GGAA microsatellite enhancers
2016-10-28 | GSE73616 | GEO
Project description:BET bromodomain dependency in EWS/ETS driven Ewing Sarcoma
| PRJNA453371 | ENA
Project description:Ewing sarcomas are characterized by the presence of EWS/ETS fusion genes in the absence of other recurrent genetic alterations and mechanisms of tumor heterogeneity that contribute to disease progression remain unclear. Mutations in the Wnt/beta-catenin pathway are rare in Ewing sarcoma but the Wnt pathway modulator LGR5 is often highly expressed, suggesting a potential role for the axis in tumor pathogenesis. We evaluated beta-catenin and LGR5 expression in Ewing sarcoma cell lines and tumors and noted marked intra- and inter-tumor heterogeneity. Tumors with evidence of active Wnt/beta-catenin signaling were associated with increased incidence of tumor relapse and worse overall survival. Paradoxically, RNA sequencing revealed a marked antagonism of EWS/ETS transcriptional activity in Wnt/beta-catenin activated tumor cells. Consistent with this, Wnt/beta-catenin activated cells displayed a phenotype that was reminiscent of Ewing sarcoma cells with partial EWS/ETS loss of function. Specifically, activation of Wnt/beta-catenin induced alterations to the actin cytoskeleton, acquisition of a migratory phenotype and up regulation of EWS/ETS-repressed genes. Notably, activation of Wnt/beta-catenin signaling led to marked induction of tenascin C (TNC), an established promoter of cancer metastasis, and an EWS/ETS-repressed target gene. Loss of TNC function in Ewing sarcoma cells profoundly inhibited their migratory and metastatic potential. Our studies reveal that heterogeneous activation of Wnt/beta-catenin signaling in subpopulations of tumor cells contributes to phenotypic heterogeneity and disease progression in Ewing sarcoma. Significantly, this is mediated, at least in part, by inhibition of EWS/ETS fusion protein function that results in de-repression of metastasis-associated gene programs.
2016-11-30 | GSE75859 | GEO
Project description:Pediatric cancers frequently harbor sentinel mutations involving transcription factors (TFs) that dysregulate normal development. A recurrent mechanism involves the ability of mutant TFs to co-opt cell lineage-specific, activating TFs to promote cancer growth. Ewing sarcoma, the second most common pediatric bone cancer, is defined by the presence of a 11;22 chromosomal translocation fusing the N-terminus of the EWS protein with the C-terminal DNA binding domain of an ETS (E26 Transformation Specific) TF family member, most commonly (85-90% of cases), FLI1. The EWS/FLI fusion exhibits the neomorphic ability to pioneer de novo enhancers at repeating 5’-GGAA-3’ motifs in the cell-of-origin, which has not been identified. To date, efforts to elucidate the key mechanisms by which EWS/FLI promotes oncogenesis have prioritized identifying the genes that are profoundly activated by EWS/FLI and highly expressed in Ewing sarcoma compared to other cancers, with particular focus on transcription factors capable of altering cell state. However, it is not known whether, globally, these genes constitute the most critical drivers of Ewing sarcoma cell growth. Here, we describe the results of an unbiased deletion screen revealing that the wild-type repressive ETS family TF, ETV6 (ETS Variant 6, or TEL), is a novel and most critical TF dependency specific to Ewing sarcoma. We demonstrate that the repressive activity of ETV6 constrains EWS/FLI gene activation at GGAA repeat enhancers to promote Ewing sarcoma cell growth.
2022-10-05 | GSE181553 | GEO