This 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 SamplesHuman 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 SamplesThis study aims to identify the cell of origin of Langerhans Cell Histiocytosis and the molecular mechanisms of its pathogenesis.
No associated publication
Specimen part, Treatment
View SamplesLangerhans cell histiocytosis (LCH) is a disease characterized by the accumulation of eponymous CD1a+ Langerin+ Langerhans-cell (LC)-like dendritic cells (DC) of largely unknown origin. Here we have performed comparative transcriptome analysis of highly purified CD207+/CD1a+ Langerhans cell histiocytosis (LCH) cells derived from different locations and disease courses and three major human dendritic cell lineages: epidermal Langerhans cells, myeloid dendritic cells (mDC1) and plasmacytoid dendritic cells (pDC) in order to investigate the relationship between LCH cells and naturally occurring dendritic cells. Data obtained indicate that LCH cells form a distinct DC entity. Furthermore, we have identified transcripts that are uniquely expressed by LCH cells in comparison to LC, mDC1, and pDC, and induce LCH-specific features in human DC.
Notch is active in Langerhans cell histiocytosis and confers pathognomonic features on dendritic cells.
Specimen part
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 SamplesTranslocations of ETS transcription factors are driver mutations in diverse cancers. We investigated the genomic network of the ETS fusion EWS/FLI1 in Ewing's sarcoma (ESFT) as a model of ETS-driven tumorigenesis. ChIP-Seq and transcriptional analysis identified E2F3 as a principle co-factor of EWSFLI1 defining functionally distinct gene sets. While EWS/FLI1 binding independent of E2F3 predominantly associated with repressed differentiation genes, significant co-localization with E2F3 was discovered at proximal promoters of activated growth-related genes. Thus, EWS/FLI1 promotes oncogenesis by simultaneously perturbing differentiation state and augmenting the expression of genes co-regulated by E2F3. Integration of additional E2F3 and ERG localization data from prostate cancer containing TMPRSS2/ERG verified that the ETS-E2F module is also found in prostate cancer and may be of general relevance to ETS driven cancers.
Oncogenic ETS fusions deregulate E2F3 target genes in Ewing sarcoma and prostate cancer.
Disease, Cell line, Treatment, Time
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 SamplesHypoxia is an important condition in the tumor cell microenvironment and approximately 1-1.5% of the genome is transcriptionally responsive to hypoxia with hypoxia-inducible factor-1 (HIF-1) as a major mediator of transcriptional activation. Tumor hypoxia is associated with a more aggressive phenotype of many cancers in adults, but data on pediatric tumors are scarce. By immunohistochemical analysis, HIF-1 expression was readily detectable in 18/28 primary Ewings sarcoma family tumors (ESFT), a group of highly malignant bone-associated tumors in children and young adults, which encouraged us to study the effect of hypoxia on ESFT cell lines in vitro.
Hypoxia modulates EWS-FLI1 transcriptional signature and enhances the malignant properties of Ewing's sarcoma cells in vitro.
Disease, Cell line
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 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 Samples