Similar Datasets
Project description:The glucocorticoid receptor (GR) acts as a ubiquitous cortisol-dependent transcription factor (TF). To identify co-factors, we used protein-fragment complementation assays and found that GR recognizes FLI1 and additional ETS family proteins, TFs relaying proliferation and/or migration signals. Following steroid-dependent translocation of FLI1 and GR to the nucleus, the FLI1-specific domain (FLS) binds with GR and strongly enhances GR's transcriptional activity. This interaction has functional consequences in Ewing sarcoma (ES), childhood and adolescence bone malignancies driven by fusions between EWSR1 and FLI1. In vitro, GR knockdown inhibited the migration and proliferation of ES cells, and in animal models, antagonizing GR (or lowering cortisol) retarded both tumor growth and metastasis from bone to lung. Taken together, our findings offer mechanistic rationale for repurposing GR-targeting drugs for the treatment of patients with ES.
| S-EPMC6899513 | biostudies-literature
Project description:ETS family proteins bind glucocorticoid receptor: relevance for treatment of Ewing sarcoma
| PRJNA558012 | ENA
Project description:We show that EWS-FLI1, an aberrant transcription factor responsible for the pathogenesis of Ewing sarcoma, reprograms gene regulatory circuits by directly inducing or directly repressing enhancers. At GGAA repeats, which lack regulatory potential in other cell types and are not evolutionarily conserved, EWS- FLI1 multimers potently induce chromatin opening, recruit p300 and WDR5, and create de novo enhancers. GGAA repeat enhancers can loop to physically interact with target promoters, as demonstrated by chromosome conformation capture assays. Conversely, EWS-FLI1 inactivates conserved enhancers containing canonical ETS motifs by displacing wild-type ETS transcription factors and abrogating p300 recruitment. ChIP-seq for of 4 histone modifications (H3K27ac, H3K4me1, H3K4me3 and H3K27me3), FLI1, p300, WDR5, ELF1 and GABPA in primary Ewing sarcomas, Ewing sarcoma cell lines (A673 and SKMNC cells), and mesenchymal stem cells (MSC). EWS-FLI1 was knocked down in Ewing sarcoma cell lines with lentiviral shRNAs (shFLI1 and shGFP control). EWS-FLI1 was expressed in MSCs with lentiviral expression vectors (pLIV EWSFLI1 or pLIV empty vector control). * Raw data not provided for the MSC and Primary Ewing sarcoma samples. *
2014-10-30 | E-GEOD-61944 | biostudies-arrayexpress
Project description:We show that EWS-FLI1, an aberrant transcription factor responsible for the pathogenesis of Ewing sarcoma, reprograms gene regulatory circuits by directly inducing or directly repressing enhancers. At GGAA repeats, which lack regulatory potential in other cell types and are not evolutionarily conserved, EWS- FLI1 multimers potently induce chromatin opening, recruit p300 and WDR5, and create de novo enhancers. GGAA repeat enhancers can loop to physically interact with target promoters, as demonstrated by chromosome conformation capture assays. Conversely, EWS-FLI1 inactivates conserved enhancers containing canonical ETS motifs by displacing wild-type ETS transcription factors and abrogating p300 recruitment. Ewing sarcoma cell lines (A673 and SKNMC) were analyzed by RNA-seq. EWS-FLI1 was depleted by infection with lentiviral shRNAs (shFLI1 and shGFP control).
2014-10-30 | E-GEOD-61950 | 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. 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:To get insight in the functional role of EGR2 for Ewing sarcoma, we performed a transcriptional profiling of Ewing sarcoma cells after knockdown of EGR2 and compared the resulting transcriptional signature with that of EWSR1-FLI1-silenced Ewing sarcoma cells. In accordance with the strong EGR2-induction by EWSR1-FLI1, both genes highly significantly overlap in their transcriptional signatures. Gene-set enrichment analyses (GSEA) and DAVID (Database for Annotation, Visualisation and Integrated Discovery) gene ontology analyses indicated a strong impact of EGR2 on cholesterol and lipid biosynthesis resembling its function in orchestrating lipid metabolism of myelinating Schwann cells. A673 and SK-N-MC Ewing sarcoma cells were transfected with specific siRNAs directed against EGR2 or EWSR1-FLI1 or non-targeting control siRNA. 48 h thereafter RNA was harvested and processed for microarray analysis.
2015-07-26 | E-GEOD-62090 | biostudies-arrayexpress
Project description:Comparison of gene expression profile of Ewing sarcoma cells which have an exchange of the endogenous EWS/FLI1 to either wild-type or a turnover-deficient mutant EWS/FLI1. Most target genes are saturated as only a few target genes are soly driven by increasing protein amount. The effect of a stable EWS/FLI1 mutant on global gene expression was evaluated in A673 Ewing sarcoma cells.
2016-11-16 | GSE81018 | GEO
Project description:Expression profiling of Ewing sarcoma samples in the frame of the CIT program from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net). STAG2 loss-of-function mutation is the most frequent secondary genetic alteration in Ewing sarcoma, an aggressive bone tumor driven by the chimeric EWSR1-FLI1 transcription factor. STAG2 encodes an integral member of the cohesin complex, a ring-shaped multi-protein structure, which is essential to shape the architecture and expression of the genome with CTCF. Combining this cohort with our previously published series (GSE34620), we show that a signature of commonly downregulated genes upon STAG2 mutation in A673 and TC71 and linked to at least one EWSR1-FLI1 bound GGAA microsatellite enhancer chain element inferred form H3K27ac HiChIP predict poor overall survival in Ewing sarcoma patients.
2021-04-29 | GSE142162 | GEO
Project description:Transcriptomic analysis of the well-characterized Ewing sarcoma cell line A673 indicated that one of the genes more strongly upregulated by EWSR1-FLI1 was FEZF1 (FEZ family zinc finger protein 1), a transcriptional repressor involved in brain development and neural cell identity. FEZF1 was highly expressed in Ewing sarcoma cells but not in other bone tumors such as osteosarcoma or chondrosarcoma. FEZF1 promoter contains a large GGAA-microsatellite and the number of GGAA repeats correlated positively with FEZF1 expression levels in Ewing sarcoma cell lines. To characterize the functional role of FEZF1 in Ewing sarcoma we analyzed the effect of FEZF1 knockdown in three Ewing sarcoma cell lines (A673, SKNMC, SKES1). FEZF1 knockdown inhibited clone formation in clonogenic assays and cell proliferation. Finally, we analyzed the FEZF1-dependent expression profile in A673 cells by RNAseq. Interestingly, several neural genes regulated by FEZF1 were concomitantly regulated by EWSR1-FLI1. In summary, FEZF1 is a transcriptional target of EWSR1-FLI1 in Ewing sarcoma cells involved in the regulation of neural-specific genes which could explain, at least in part, the neural-like phenotype observed in several Ewing sarcoma tumors and derived cell lines.
2021-11-22 | GSE184679 | GEO
Project description:We have performed a high-throughput RNA interference screen to identify targets inhibiting EWS-FLI1 driven cell proliferation in Ewing sarcoma cells. EWS-FLI1 expressing A673 Ewing sarcoma cells were screened both in presence and absence of EWS-FLI1 shRNA induction with druggable siRNA library. Leucine rich repeats and WD repeat Domain containing 1 (LRWD1) targeting siRNA pool was the strongest anti-proliferative hit identified only in presence of EWS-FLI1. Validation experiments confirmed the anti-proliferative effect of LRWD1 depletion especially in EWS-FLI1 expressing cells. Functional analysis of differentially expressed genes in LRWD1 depleted Ewing sarcoma cells showed over-representation of connective tissue development, cell projection morphogenesis and neuronal processes.
2018-09-16 | GSE73092 | GEO