EWS-FLI1 is a chimeric ETS transcription factor that is, due to a chromosomal rearrangement, specifically expressed in Ewings sarcoma family tumors (ESFT) and is thought to be the initiating event in the development of the disease. Previous genomic profiling experiments have identified a number of EWS-FLI1 regulated genes and genes that discriminate ESFT from other sarcomas, but so far a comprehensive analysis of EWS-FLI1 dependent molecular functions characterizing this aggressive cancer is lacking. In this study a molecular function map of ESFT was constructed based on an integrative analysis of gene expression profiling experiments on a uniform microarray platform following EWS-FLI1 knockdown in a panel of five ESFT cell lines, and on gene expression data from the same platform of 59 primary ESFT tumors. Based on the assumption that EWS-FLI1 is the driving transcriptional force in ESFT pathogenesis, we predicted an inverse correlation of gene expression for EWS-FLI1 regulated genes between the putative tissue of origin and the cell lines under EWS-FLI1 knockdown conditions. Consistent with recent reports, mesenchymal progenitor cells (MPC) were found to fit this hypothesis best and were therefore used as the reference tissue for the construction of the molecular function map in ESFT.
A molecular function map of Ewing's sarcoma.
No sample metadata fields
View SamplesThough p53 mutations are rare in Ewing sarcoma, there is a strong indication that p53-mutant tumors form a particularly bad prognosis group. As such, novel treatment strategies are warranted that would specifically target and eradicate tumor cells containing mutant-p53 in this subset of ES patients.
Variability in functional p53 reactivation by PRIMA-1(Met)/APR-246 in Ewing sarcoma.
Specimen part
View SamplesTransient transfection of a Ewing's Sarcoma cell line expressing type I EWS-FLI1 fusion and doxycycline-inducible short hairpin RNA against EWS-FLI1 (A673sh)
Suppression of FOXO1 is responsible for a growth regulatory repressive transcriptional sub-signature of EWS-FLI1 in Ewing sarcoma.
Cell line
View SamplesMicroRNAs serve to fine-tune gene expression and play an important regulatory role in tissue specific gene networks. The identification and validation of miRNA target genes in a tissue still poses a significant problem since the presence of a seed sequence in the 3´UTR of an mRNA and its expression modulation upon ectopic expression of the miRNA do not reliably predict regulation under physiological conditions. The chimeric oncoprotein EWS-FLI1 is the driving pathogenic force in Ewing Sarcoma. miR-17-92, one of the most potent oncogenic miRNAs, was recently reported to be the top EWS-FLI1 activated miRNA. Using a combination of AGO2 pull-down experiments by PAR-CLIP (Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation) and of RNAseq upon miRNA depletion by ectopic sponge expression, we aimed to identify the targetome of miR-17-92 in Ewing sarcoma. Intersecting both datasets we found an enrichment of PAR-CLIP hits for members of the miR-17-92 cluster in the 3´UTRs of genes up-regulated in response to mir-17-92 specific sponge expression. Strikingly, approximately a quarter of these genes annotate to the TGFB/BMP pathway, the majority mapping downstream of SMAD signalling. Taken together, our findings shed light on the complex miRegulatory landscape of Ewing Sarcoma pointing miR-17-92 as a key node connected to TGFB/BMP pathway Overall design: mRNA profiles of a Ewings Sarcoma cellline (clone of A673 with inducible sh EWS-FLI1 knockdown) treated with microRNA sponges and controls
The role of miR-17-92 in the miRegulatory landscape of Ewing sarcoma.
Cell line, Treatment, Subject
View SamplesPosttranscriptional regulation of mRNA levels in neutrophils and its consequences for immune responses are unexplored. By employing profiling of the neutrophil transcriptome we show that the mRNA-destabilizing protein tristetraprolin (TTP) limits the expression of hundreds of genes, including genes negatively regulating apoptosis. Elicited TTP-deficient neutrophils exhibited reduced apoptosis and were increased in numbers. The anti-apoptotic protein Mcl-1 was elevated in TTP-deficient neutrophils and Mcl1 mRNA was bound and destabilized by TTP. Ablation of TTP in macrophages and neutrophils resulted in an improved defense and survival of mice during invasive infection with Streptococcus pyogenes. Mice lacking myeloid TTP prevented dissemination of bacteria and efficiently blunted systemic disease by massive but controlled neutrophil deployment. These data identify posttranscriptional control by TTP to restrict neutrophils and antimicrobial defense. Overall design: WT and TTPKO peritoneal neutrophils stimulated with LPS for 4 h. Each condition analyzed in three replicates
The RNA-binding protein tristetraprolin schedules apoptosis of pathogen-engaged neutrophils during bacterial infection.
Subject
View SamplesAT6.1 cells transfected to over-express Ndrg-1 were compared with AT6.1 vector control cells in a microarray analysis. The aim of the study was to identify differentially expressed genes between the two cell lines, as these may be modulated by Ndrg-1.
The iron-regulated metastasis suppressor, Ndrg-1: identification of novel molecular targets.
Cell line
View SamplesAffymetrix exon array data were generated from total RNA that was isolated from localized Ewing sarcoma biopsy specimens. Expression of transcript summarized data was compared to data generated from normal stem cells and normal adult tissues.
Overexpression of HOX genes is prevalent in Ewing sarcoma and is associated with altered epigenetic regulation of developmental transcription programs.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
EWS-FLI1 perturbs MRTFB/YAP-1/TEAD target gene regulation inhibiting cytoskeletal autoregulatory feedback in Ewing sarcoma.
Cell line, Treatment
View SamplesPrecise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3’ untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3’ UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation. Overall design: Experiment comparing RNA decay rates in WT and TTP-/- macrophages at LPS 3 h and 6 h. Transcription was blocked with actinomycin D for 0, 45 or 90 min. Decay rates was calculated using linear model.
Tristetraprolin binding site atlas in the macrophage transcriptome reveals a switch for inflammation resolution.
Specimen part, Cell line, Subject, Time
View SamplesEwing Sarcoma (EwS) is a EWS-FLI1- fusion driven pediatric bone cancer with high metastatic potential. Cellular plasticity, typically regulated via the Rho-pathway, is a prerequisite for metastasis initiation. Here we interrogated the role of the Rho transcriptional effectors MRTFA/B in EwS. We find MRTFB transcriptional function strongly repressed by EWS-FLI1. Under EWS-FLI1-low (knock-down) conditions, MRTFB is activated and antagonizes global EWS-FLI1-dependent transcription. Furthermore, ChIP-Seq revealed strong overlaps in MRTFB and EWS-FLI1 chromatin occupation, especially for EWS-FLI1 suppressed-(anticorrelated) genes. Enrichment of TEAD binding motifs in these shared genomic binding regions, and overlapping transcriptional footprints of MRTFB and TEAD1-4 perturbation led us to propose synergy between MRTFB and TEAD in the regulation of EWS-FLI1 suppressed-anticorrelated genes. Finally, we find F-actin assembly to be already perturbed in our EwS model, F-actin polymerization is perturbed by EWS-FLI1 in our model cell line, however,but pharmacological inhibition of actin polymerization still reduced expression serum-induced expression of MRTFB/YAP-1/TEAD target genes. In summary our data support a model of indirect and direct EWS-FLI1-driven perturbation of MRTFB/YAP-1/TEAD target gene regulation . Overall design: 1. Transient si-RNA mediated knockdown of MRTFA (MKL-1), MRTFB (MKL-2) and doxycyline-induced EWS-FLI1 knockdown in A673/TR/shEF EwS cells (8 samples/replicate: 2 replicates total); 2. Combined transient knockdown of MRTFA, MRTFB and EWS-FLI1 in SK-N-MC EwS cells (4 samples/replicate: 2 replicates total); 3. Combined knockdown of TEAD1-4 by pooling si-RNA against TEAD1, TEAD2, TEAD3 and TEAD 4 combined with doxycycline-inducible EWS-FLI1 knockdown (4 samples/replicate: 8 samples total)
EWS-FLI1 perturbs MRTFB/YAP-1/TEAD target gene regulation inhibiting cytoskeletal autoregulatory feedback in Ewing sarcoma.
Cell line, Treatment, Subject
View Samples