Human adenovirus 5 encodes a small set of miRNAs, which are generated by DICER-mediated processing of 2 larger precursors, the so-called virus-associated RNAs I and II. To identify targets of one of the major miRNA isoforms derived from virus-associated RNAI (mivaRNAI-137), we isolated Argonaute complexes of mivaRNAI-137-transfected cells and analyzed co-purifying RNAs by microarray analysis. RNAs enriched in Argonaute complexes of mivaRNAI-137-transfected cells compared to cells transfected with a control siRNA were identified and subjected to further validation. RNAs specifically associated with Argonaute-containining complexes of adenovirus 5-infected cells were identified as well.
Identification of RISC-associated adenoviral microRNAs, a subset of their direct targets, and global changes in the targetome upon lytic adenovirus 5 infection.
Cell line
View SamplesBackground: ETV6/RUNX1 (E/R) (also known as TEL/AML1) is the most frequent gene fusion in childhood acute lymphoblastic leukemia (ALL) and also most likely the crucial factor for disease initiation, whereas its role in leukemia propagation and maintenance remains largely elusive. To address this issue we performed a shRNA-mediated knock-down (KD) of the E/R fusion gene and investigated the ensuing consequences on genome-wide gene expression patterns and deducible regulatory functions in two E/R-positive leukemic cell lines. Findings: Microarray analyses identified 777 genes whose expression was substantially altered. Although approximately equal proportions were either up- (KD-UP) or down-regulated (KD-DOWN), the effects on biological processes and pathways differed considerably. The E/R KD-DOWN set was significantly enriched for genes included in the cell activation, immune response, apoptosis, signal transduction and development and differentiation categories, whereas in the E/R KD-UP set only the PI3K/AKT/mTOR signaling and hematopoietic stem cells categories became evident. Comparable expression signatures obtained from primary E/R-positive ALL samples underline the relevance of these pathways and molecular functions. We also validated six differentially expressed genes representing the categories stem cell properties, B-cell differentiation, immune response, cell adhesion and DNA damage with RT-qPCR. Conclusion: The results of our analyses provide the first preliminary evidence that the continuous expression of the E/R fusion gene interferes with regular B-cell development by repressing key functions that are necessary under physiological circumstances. E/R may thus constitute also the essential driving force for the propagation and maintenance of the leukemic process irrespective of potential consequences of associated secondary changes. Finally, these findings may also provide a valuable source of potentially attractive therapeutic targets.
The leukemia-specific fusion gene ETV6/RUNX1 perturbs distinct key biological functions primarily by gene repression.
Cell line, Treatment
View SamplesEWS-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 SamplesPAX5-JAK2 has recently been identified as a novel recurrent fusion gene in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) but the function of the encoded chimeric protein has not yet been characterized in detail. Herein we show that the PAX5-JAK2 chimera, which consists of the DNA-binding paired domain of PAX5 and the active kinase domain of JAK2, is a nuclear protein that has the ability to bind to wild-type PAX5 target loci. Moreover, our data provide compelling evidence that PAX5-JAK2 functions as nuclear catalytically active kinase that autophosphorylates and in turn phosphorylates and activates downstream STATs in an apparently non-canonical mode. The chimeric protein also enables cytokine-independent growth of Ba/F3 cells and, therefore, possessing transforming potential. Importantly, the kinase activity of PAX5-JAK2 can be efficiently blocked by JAK2 inhibitors rendering it a potential target for therapeutic intervention. Together, our data show that PAX5-JAK2 simultaneously deregulates the PAX5 downstream transcriptional program and activates the JAK-STAT signaling cascade, and thus, by interfering with these two important pathways, may promote leukemogenesis.
The role of the Janus-faced transcription factor PAX5-JAK2 in acute lymphoblastic leukemia.
Specimen part, Disease, Disease stage
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 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 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 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 .
EWS-FLI1 perturbs MRTFB/YAP-1/TEAD target gene regulation inhibiting cytoskeletal autoregulatory feedback in Ewing sarcoma.
Cell line
View Samples