BRCA1, R-loops and Recombination defects in Ewing's sarcoma
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ABSTRACT:
PROVIDER: PRJNA283863 | ENA |
REPOSITORIES: ENA
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Project description:Ewing’s sarcoma family of tumors (ESFT) is an aggressive pediatric bone and soft tissue cancer. It is the prototypical example of mesenchymal tumors driven by a fusion oncogene involving the ewing sarcoma break point region 1 (EWSR1) gene, most frequently– EWS-FLI1. We have discovered that loss of EWSR1 leads to accumulation of R-loops, replication stress and impaired homologous recombination, recapitulating breast cancer 1, early onset (BRCA1) deficiency. EWS-FLI1 acts dominant negatively in ESFT to impart the same phenotypes. Further we demonstrate that in ESFT, BRCA1 predominantly associates with the elongating transcription machinery and is unavailable for DNA strand break repair. Gene expression profiling identified upregulated compensatory mechanisms in ESFT cells to process increased R-loops (RNASEH2 and FEN1) and replication stress (Fanconi Anemia). Taken together, our data identifies BRCA1 sequestration due to transcription stress as the mechanistic basis for ESFT chemosensitivity and suggests potential targets for the much lacking second-line therapy.
2018-03-09 | GSE68845 | GEO
Project description:Ewing’s sarcoma family of tumors (ESFT) is an aggressive pediatric bone and soft tissue cancer. It is the prototypical example of mesenchymal tumors driven by a fusion oncogene involving the ewing sarcoma break point region 1 (EWSR1) gene, most frequently– EWS-FLI1. We have discovered that loss of EWSR1 leads to accumulation of R-loops, replication stress and impaired homologous recombination, recapitulating breast cancer 1, early onset (BRCA1) deficiency. EWS-FLI1 acts dominant negatively in ESFT to impart the same phenotypes. Further we demonstrate that in ESFT, BRCA1 predominantly associates with the elongating transcription machinery and is unavailable for DNA strand break repair. Gene expression profiling identified upregulated compensatory mechanisms in ESFT cells to process increased R-loops (RNASEH2 and FEN1) and replication stress (Fanconi Anemia). Taken together, our data identifies BRCA1 sequestration due to transcription stress as the mechanistic basis for ESFT chemosensitivity and suggests potential targets for the much lacking second-line therapy.
2018-03-09 | GSE68836 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2018-03-09 | GSE68847 | 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.
2011-11-01 | GSE31185 | GEO
Project description:Ewing sarcoma (EwS) is an aggressive pediatric bone and soft tissue cancer. It is driven by a fusion oncogene involving the EWSR1 gene, predominantly EWS-FLI1. EwS is exquisitely sensitive to genotoxic agents, but the molecular basis for this sensitivity is relatively underexplored. We have discovered that EwS displays alterations in damage-induced transcription regulation and an accumulation of R-loops. Consequently, we observe an increase in replication stress but impaired homologous recombination. We demonstrate an enriched interaction between BRCA1 and the elongating transcription machinery and suggest that this interaction may be the underlying cause for impaired recombination. Investigation into the unique transcription profile of EwS also revealed upregulated mechanisms (including RNASEH2, FEN1 and Fanconi Anemia pathway) to compensate for the increased EWS-FLI1 induced toxicity. Finally, we have uncovered a novel role for EWSR1 transcriptional response to damage, suppressing R-loops and promoting homologous recombination. Taken together, our findings improve the current understanding of wild-type EWSR1 function, elucidate the mechanistic basis for EwS chemosensitivity (including PARP1 inhibitors) and suggest potential targets for novel second-line therapy.
2018-03-09 | GSE87324 | 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:Affymetrx U95Av2 GeneChip hybridizations, RNA extracted from primary human pediatric alveolar (aRMS) and embryonal (eRMS) rhabdomyosarcoma, plus primary pediatric Ewing's sarcoma (EWS) Keywords = pediatric sarcoma Keywords = Ewing's sarcoma Keywords = rhabdomyosarcoma Keywords: other
2004-03-13 | GSE967 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE31185: The human Ewing's Sarcoma oncoprotein EWS-FLI1 causes developmental defects in zebrafish embryos GSE31186: The human Ewing's Sarcoma oncoprotein EWS-FLI1 causes Ewing's-type tumors in zebrafish Refer to individual Series
2011-11-01 | E-GEOD-31217 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE37370: microRNA expression data from Ewing's sarcoma tumor samples GSE37371: Expression data from Ewing's sarcoma tumor samples Refer to individual Series
2012-06-11 | E-GEOD-37372 | biostudies-arrayexpress
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. Somatic, mosaic expression of human EWS-FLI1 in zebrafish from the heat shock promoter [Tg(HSP:EWS-FLI1)] caused small round blue cell tumors (SRBCTs) similar to human Ewing's sarcoma. We performed microarray studies comparing zebrafish SRBCTs to another tumor type, zebrafish malignant peripheral nerve sheath tumors (MPNSTs). The results identify a conserved set of EWS-FLI1-regulated genes,and provide insight into the pathogenesis of Ewing's Sarcoma tumors.
2011-11-01 | GSE31186 | GEO