Project description:We compared the expression changes in Ewing sarcoma cell lines following treatment with 2 known 20S proteasome inhibitors versus 2 novel compounds
Project description:Purpose: Our experimental results demonstrate an essential role for the lncRNA HOTAIR in Ewing sarcoma. We have repressed HOTAIR expression in three Ewing sarcoma cell lines and overexpressed HOTAIR, alone and with EWS-FLI1, in htert-immortalized human mesenchymal stem cells to evaluate its effects on gene expression in this cancer. Methods: RNA-Seq of Ewing sarcoma cell lines with HOTAIR represssed by GapmeR or treated with nonsilencing control, and hTERT-immortalized hMSCs with expression of control GFP, HOTAIR, or HOTAIR and EWS-FLI1, was used for gene expression analysis. Results: Defined gene expression signatures were defined as driven by HOTAIR in each cell line model, with a consensus set of gene identified in the Ewing sarcoma cell lines. Additionally, a set of genes regulated by HOTAIR independently of EWS-FLI1 was identified in the hTERT-hMSC models. Conclusions: HOTAIR expression regulates a set of genes critical to viability, cell adhesion, cell motility, and other markers of EMT and metastasis in Ewing sarcoma, independently of EWS-FLI1.
Project description:An increasing number of cancer-associated mutations have been identified. Unfortunately, little therapy today exploits these tumor-specific genetic lesions. Often, the resulting oncoproteins have been intractable to easy manipulation with current small molecule screening approaches. To overcome this impasse, we developed an expression-based approach to small molecule library screening. We applied this platform to the discovery of modulators of the activity of EWS/FLI, the Ewing sarcoma associated oncoprotein. Cytarabine (ARA-C) was identified as the top hit in a small molecule library screen. ARA-C modulates EWS/FLI by decreasing EWS/FLI protein level and has striking effects on cellular viability and transformation in in vitro and in vivo models of Ewing sarcoma. With poor outcomes for patients with relapsed Ewing sarcoma and the well established safety profile of ARA-C, clinical trials testing ARA-C in Ewing sarcoma are warranted. Expression data was created for A673 cells treated with ARA-C and two other compounds used to treat Ewing sarcoma (Puromycin and Doxorubicin) at two doses (EC50 and 2xEC50) and three time points (24 hours, 3 days, and 5 days). Experiment Overall Design: A673 cells were treated with ARA-C (at doses of EC50 and 2xEC50) or vehicle in triplicate and expression profiled at 24 hours, 3 days, and 5 days. To exclude the possibility that ARA-C's modulation of the EWS/FLI signature was simply a non-specific response to treatment with all cytotoxic agents, we asked whether other compounds known to kill Ewing sarcoma cells (Doxorubicin and Puromycin) would induce the EWS/FLI off genome-wide expression pattern. A673 cells were treated with Doxorubicin and Puromycin (at doses of EC50 and 2xEC50) and expression profiled at 24 hours, 3 days, and 5 days.
Project description:This SuperSeries is composed of the following subset Series: GSE30513: MicroRNA expression profiling of Ewing sarcoma cancer stem cells GSE31144: MicroRNA expression profiling of Ewing sarcoma cell lines upon TARBP2 depletion GSE31145: MicroRNA expression profiling of Ewing sarcoma spheres vs. adherent cells Refer to individual Series
Project description:Tumor: tumor microenvironment (TME) interactions are critical for tumor progression and the composition and structure of the local extracellular matrix (ECM) are key determinants of tumor metastasis. We recently reported that activation of Wnt/beta- catenin signaling in Ewing sarcoma cells induces widespread transcriptional changes that are associated with acquisition of a metastatic tumor phenotype. Significantly, ECM protein-encoding genes were found to be enriched among Wnt/beta-catenin induced transcripts, leading us to hypothesize that activation of canonical Wnt signaling might induce changes in the Ewing sarcoma secretome. To address this hypothesis, conditioned media from Ewing sarcoma cell lines cultured in the presence or absence of Wnt3a was collected for proteomic analysis. Label-free mass spectrometry was used to identify and quantify differentially secreted proteins. We then used in silico databases to identify only proteins annotated as secreted. Comparison of the secretomes of two Ewing sarcoma cell lines revealed numerous shared proteins, as well as a degree of heterogeneity, in both basal and Wnt-stimulated conditions. Gene set enrichment analysis of secreted proteins revealed that Wnt stimulation reproducibly resulted in increased secretion of proteins involved in ECM organization, ECM receptor interactions, and collagen formation. In particular, Wnt-stimulated Ewing sarcoma cells upregulated secretion of structural collagens, as well as matricellular proteins, such as the metastasis-associated protein, tenascin C (TNC). Interrogation of published databases confirmed reproducible correlations between Wnt/beta-catenin activation and TNC and COL1A1 expression in patient tumors. In summary, this first study of the Ewing sarcoma secretome reveals that Wnt/beta-catenin activated tumor cells upregulate secretion of ECM proteins. Such Wnt/beta-catenin mediated changes are likely to impact on tumor: TME interactions that contribute to metastatic progression.
Project description:Primary pediatric Ewing sarcoma (ES), one uncharacterized sarcoma as well as primary and well established ES cell lines were compared to probes of different normal tissues 8 Ewing sarcoma patient samples (MuET-x), 3 primary ES cell lines (SB-KMS-y), 3 well established ES cell lines (A673, SK-N-MC, RD-ES) and 22 normal tissues (PBMC, spleen, thymus, stomach, ...., uterus, fetal brain, fetal liver) were analyzed.