ETV6 dependency in Ewing sarcoma by antagonism of EWS-FLI1-mediated enhancer activation
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE189418 | GEO | 2022/10/18
REPOSITORIES: GEO
Similar Datasets
Project description:ETV6 dependency in Ewing sarcoma by antagonism of EWS-FLI1-mediated enhancer activation
| PRJNA782979 | ENA
Project description:The EWS-FLI1 fusion oncoprotein deregulates transcription to initiate the paediatric cancer Ewing sarcoma. Here we used a domain-focused CRISPR screen to implicate the transcriptional repressor ETV6 as a unique dependency in this tumour. Using biochemical assays and epigenomics, we show that ETV6 competes with EWS-FLI1 for binding to select DNA elements enriched for short GGAA repeat sequences. Upon inactivating ETV6, EWS-FLI1 overtakes and hyper-activates these cis-elements to promote mesenchymal differentiation, with SOX11 being a key downstream target. We show that squelching of ETV6 with a dominant-interfering peptide phenocopies these effects and suppresses Ewing sarcoma growth in vivo. These findings reveal targeting of ETV6 as a strategy for neutralizing the EWS-FLI1 oncoprotein by reprogramming of genomic occupancy.
| S-EPMC10101761 | biostudies-literature
Project description:We identified global DNA binding properties of EWS-FLI1 in mouse Ewing sarcoma. GGAA microsatellites were found as binding sites of EWS-FLI1 but with less frequency than that in human Ewing sarcoma, and genomic distribution is not conserved between human and mouse.
2018-07-25 | GSE108631 | GEO
Project description:Posterior homeobox D genes, in particular HOXD13, are over-expressed by Ewing sarcoma, a tumor driven by the oncogenic fusion protein EWS-FLI1. Here, we have found that EWS-FLI1 maintains HOXD13 expression through a GGAA microsatellite enhancer in the developmental posterior HOXD regulatory domain. Activation of this enhancer is EWS-FLI1 dependent and epigenomic silencing of this region leads to loss of HOXD13 expression in Ewing sarcoma cells, but not in unrelated cells. To determine the function of HOXD13 activation in Ewing sarcoma we performed nascent RNA sequencing or RNA sequencing upon HOXD13 knockdown.
2022-06-28 | GSE148494 | GEO
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:Posterior homeobox D genes, in particular HOXD13, are over-expressed by Ewing sarcoma, a tumor driven by the oncogenic fusion protein EWS-FLI1. Here, we have found that EWS-FLI1 maintains HOXD13 expression through a GGAA microsatellite enhancer in the developmental posterior HOXD regulatory domain. RNA-seq of shHOXD13 defined HOXD13-ergulated genes, so we performed CUT&RUN for HOXD13 and histone marks (H3K27ac, H3K4me3, H3K4me1, and H3K27me3) to determine how it regulates target genes.
2022-06-28 | GSE182512 | GEO
Project description:Posterior homeobox D genes, in particular HOXD13, are over-expressed by Ewing sarcoma, a tumor driven by the oncogenic fusion protein EWS-FLI1. Here, we have found that EWS-FLI1 maintains HOXD13 expression through a GGAA microsatellite enhancer in the developmental posterior HOXD regulatory domain. Activation of this enhancer is EWS-FLI1 dependent and epigenomic silencing of this region leads to loss of HOXD13 expression in Ewing sarcoma cells, but not in unrelated cells. To determine the function of HOXD13 activation in Ewing sarcoma we performed nascent RNA sequencing upon HOXD13 knockdown. We identified NT5E as a target induced by HOXD13. NT5E encodes for the cell surface marker CD73, so we used CITE-seq to profile these cells.
2022-06-28 | GSE165973 | GEO
Project description:Response of HEK293-cells after transfection with EWS-FLI1. HEK293 cells were transfected with the expression vector pIRES2-EGFP containing type I EWS-FLI1 or empty control vector. For transient transfection standard DEAE dextran method was used and RNA was isolated 48h post transfection. For stable transfection cells were transfected using FuGENE 6 (Roche, Mannheim, Germany) and cells were selected with 400 ug/mL G418. DNA-microarray analysis was performed using Affymetrix HG-U133A microarrays.(see Staege et al. Cancer Res. 2004) Keywords = HEK293 Keywords = EWS-FLI1 Keywords = Ewing family tumors Keywords: other
2004-10-07 | GSE1822 | GEO
Project description:The fusion oncoprotein EWS-FLI1 arises from a t(11;22)(q24;q12) chromosomal translocation and causes Ewing's Sarcoma, a malignant bone tumor. The mechanism whereby EWS-FLI1 transforms cells is unknown. We made germline transgenic zebrafish expressing human EWS-FLI1 under the control of the heat shock promoter. Induction of EWS-FLI1 expression causes multiple defects in embryonic development. We compared gene expression in control and transgenic EWS-FLI1 zebrafish. The results identify a conserved set of EWS-FLI1-regulated genes, and provide insight into the pathogenesis of Ewing's Sarcoma tumors. We performed heat shock and isolated total RNA for microarray studies comparing wildtype AB strain zebrafish with transgenic zebrafish expressing human EWS-FLI1 [Tg(HSP:EWS-FLI1)]. RNA was biotin-lableled and hybridized to zebrafish-specific Affymetrix arrays.
2011-11-01 | E-GEOD-31185 | biostudies-arrayexpress
Project description:The synthesis and processing of mRNA, from transcription to translation initiation, often requires splicing of intragenic material. The final mRNA composition varies based upon proteins that modulate splice site selection. EWS-FLI1 is an Ewing sarcoma (ES) oncogene with an interactome that we demonstrate to have multiple partners in spliceosomal complexes. We evaluate EWS-FLI1 upon post-transcriptional gene regulation using both exon array and RNA-seq. Genes that potentially regulate oncogenesis including CLK1, CASP3, PPFIBP1, and TERT validate as alternatively spliced by EWS-FLI1. EWS-FLI1 also alters splicing by directly binding to known splicing factors including DDX5, hnRNPK, and PRPF6. Reduction of EWS-FLI1 produces an isoform of g-TERT that has increased telomerase activity compared to WT TERT. The small molecule YK-4-279 is an inhibitor of EWS-FLI1 oncogenic function that disrupts specific protein interactions including DDX5 and RNA helicase A (RHA) that alters RNA splicing ratios. As such, YK-4-279 validates the splicing mechanism of EWS-FLI1 showing alternatively spliced gene patterns that significantly overlap with EWS-FLI1 reduction and WT human mesenchymal stem cells. Exon array analysis of 75 ES patient samples show similar isoform expression patterns to cell line models expressing EWS-FLI1, supporting the clinical relevance of our findings. These experiments establish systemic alternative splicing as an oncogenic process modulated by EWS-FLI1. EWS-FLI1 modulation of mRNA splicing may provide insight into the contribution of splicing towards oncogenesis, and reciprocally, EWS-FLI1 interactions with splicing proteins may inform the splicing code. Alternative splicing of RNA allows a limited number of coding regions in the human genome to produce proteins with diverse functionality. Alternative splicing has also been implicated as an oncogenic process. Identifying aspects of cancer cells that differentiate them from non-cancer cells remains an ongoing challenge and our research suggests that alternatively spliced mRNA and subsequent protein isoforms will provide new anti-cancer targets. We determined that the key oncogene of Ewing sarcoma (ES), EWS-FLI1, regulates alternative splicing in multiple cell line models. These experiments establish oncogenic aspects of splicing which are specific to cancer cells and thereby illuminate potentially oncogenic splicing shifts as well as provide a useful stratification mechanism for ES patients. We analyzed three models of EWS-FLI1 using Affymetrix GeneChip Human Exon 1.0 ST microarray: (i) Ewing's sarcoma TC32 wild-type cells expressing EWS-FLI1, and TC32 cells where EWS-FLI1 was reduced with a lentiviral shRNA; (ii) A673i, which has a doxycycline-inducible shRNA to reduce EWS-FLI1 expression, and wild-type EWS-FLI1 to screen for alternative splicing as measured by exon-specific expression changes; and (iii) human mesenchymal stem cells (hMSC), a putative cell of origin of Ewing's sarcoma, exogenously expressing EWS-FLI1, and hMSC wild-type cells without EWS-FLI1. Three biological replicates were included for each condition. The Bioconductor package "oligo" in the R programming language was used for normalization and background correction. Analysis was carried out using only core probesets, as defined by the manufacturer.
2015-03-31 | E-GEOD-65941 | biostudies-arrayexpress