The long non-coding RNA lnc277 mediates a repressive gene signature in Ewing's sarcoma and is required for oncogenesis
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Dedeepya Vaka
PROVIDER: E-GEOD-60891 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Ewing sarcoma is a highly aggressive tumor characterized by a translocation between members of the FET family of RNA binding proteins and one of several ETS transcription factors, with the most common translocation being EWS-FLI1. EWS-FLI1 leads to changes in gene expression through mechanisms that are not completely understood. We performed RNA sequencing analysis on primary pediatric human mesenchymal progenitor cells (pMPCs) expressing EWS-FLI1 in order to identify novel target genes. This analysis identified lnc277 as a previously uncharacterized long non-coding RNA upregulated by EWS-FLI1 in pMPCs. Inhibiting the expression of lnc277 diminished the ability of Ewing sarcoma cell lines to proliferate and form colonies in soft agar whereas inhibiting lnc277 had no effect on other cell types tested. By analyzing gene expression after shRNA knockdown, we found that both EWS-FLI1 and lnc277 repressed many more genes that they induced and that a significant fraction of EWS-FLI1 repressed targets were also repressed by lnc277. Analysis of primary human Ewing sarcoma RNA sequencing data further supports a role for lnc277 in mediating gene repression. We identified hnRNPK as an RNA binding protein that interacts directly with lnc277. We found a significant overlap in the genes repressed by hnRNPK and those repressed by both EWS-FLI1 and lnc277, suggesting that hnRNPK participates in lnc277 mediated gene repression. Thus, lnc277 is a previously uncharacterized long non-coding RNA downstream of EWS-FLI1 that facilitates the development of Ewing sarcoma via the repression of target genes. Our studies identify a novel mechanism of oncogenesis downstream of a chromosomal translocation and underscore the importance of lncRNA-mediated gene repression as a mechanism of EWS-FLI1 transcriptional regulation. RNA from primary human bone marrow derived mesenchymal cells either control or with inducible expression of EWS-FLI1 for 13 days was used to prepare PolyA selected cDNA libraries.
2014-11-01 | E-GEOD-60889 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below.
2014-11-01 | GSE60891 | GEO
Project description:Most Ewing's sarcomas harbor chromosomal translocations that encode fusions between EWS and ETS family members. The most common fusion, EWS/FLI, consists of an EWSR1-derived strong transcriptional activation domain fused, in-frame, to the DNA-binding domain-containing portion of FLI1. EWS/FLI functions as an aberrant transcription factor to regulate genes that mediate the oncogenic phenotype of Ewing's sarcoma. One of these regulated genes, NR0B1, encodes a corepressor protein, and likely plays a transcriptional role in tumorigenesis. However, the genes that NR0B1 regulates and the transcription factors it interacts with in Ewing's sarcoma are largely unknown. We used transcriptional profiling and chromatin immunoprecipitation to identify genes that are regulated by NR0B1, and compared these data to similar data for EWS/FLI. Although the transcriptional profile overlapped as expected, we also found that the genome-wide localization of NR0B1 and EWS/FLI overlapped as well, suggesting that they regulate some genes coordinately. Further analysis revealed that NR0B1 and EWS/FLI physically interact. This protein-protein interaction is likely to be relevant for the development of Ewing's sarcoma because mutations in NR0B1 that disrupt the interaction have transcriptional consequences and also abrogate oncogenic transformation. Taken together, these data suggest that EWS/FLI and NR0B1 physically interact, coordinately modulate gene expression, and mediate the transformed phenotype of Ewing's sarcoma.
| S-EPMC2789197 | biostudies-other
Project description:EWS/FLI is a master regulator of Ewing's sarcoma formation. Gene expression studies in A673 Ewing's sarcoma cells have demonstrated that EWS/FLI downregulates more genes than it upregulates, suggesting that EWS/FLI, and/or its targets, function as transcriptional repressors. One critical EWS/FLI target, NKX2.2, is a transcription factor that contains both transcriptional activation and transcriptional repression domains, raising the possibility that it mediates portions of the EWS/FLI transcriptional signature. We now report that microarray analysis demonstrated that the transcriptional profile of NKX2.2 consists solely of downregulated genes, and overlaps with the EWS/FLI downregulated signature, suggesting that NKX2.2 mediates oncogenic transformation via transcriptional repression. Structure-function analysis revealed that the DNA binding and repressor domains in NKX2.2 are required for oncogenesis in Ewing's sarcoma cells, while the transcriptional activation domain is completely dispensable. Furthermore, blockade of TLE or HDAC function, two protein families thought to mediate the repressive function of NKX2.2, inhibited the transformed phenotype and reversed the NKX2.2 transcriptional profile in Ewing's sarcoma cells. Whole genome localization studies (ChIP-chip) revealed that a significant portion of the NKX2.2-repressed gene expression signature was directly mediated by NKX2.2 binding. These data demonstrate that the transcriptional repressive function of NKX2.2 is necessary, and sufficient, for the oncogenic phenotype of Ewing's sarcoma, and suggest a therapeutic approach to this disease.
| S-EPMC2291578 | biostudies-literature
Project description: Not available
| S-EPMC6984994 | biostudies-literature
Project description:Refractory and/or recurrent Ewing's sarcoma (EWS) remains a clinical challenge because the disease's resistance to therapy makes it difficult to achieve durable results with standard treatments that include chemotherapy, radiation, and surgery. Recently, insulin-like-growth-factor-1-receptor (IGF1R) antibodies have been shown to have a modest single-agent activity in EWS. Patient selection using biomarkers and understanding response and resistance mechanisms in relation to IGF1R and mammalian target of rapamycin pathways are areas of active research. Since EWS has a unique tumor-specific EWS-FLI1 t(11;22) translocation and oncogenic fusion protein, inhibition of EWS-FLI1 transcription, translation, and/or protein function may be key to eradicating EWS at the stem-cell level. Recently, a small molecule that blocks the protein-protein interaction of EWS-FLI1 with RNA helicase A has been shown in preclinical models to inhibit EWS growth. The successful application of this first-in-class protein-protein inhibitor in the clinic could become a model system for translocation-associated cancers such as EWS.
| S-EPMC2968715 | biostudies-literature
Project description:Prion-like domains have emerged as important drivers of neurodegenerative disease. Now, Boulay et al. establish that the translocated prion-like domain of the oncogenic EWS-FLI1 fusion protein enables phase-separation events, which inappropriately recruit chromatin-remodeling factors to elicit the aberrant transcriptional programs underlying Ewing's sarcoma.
| S-EPMC5639709 | biostudies-literature
Project description:The hallmark of Ewing's sarcoma (EWS) is a translocation--t(11;22)(q24;q12)--that most frequently results in the EWS/FLI1 aberrant chimeric gene. Because EWS afflicts young patients, it stands out among the diverse sarcoma subtypes. The frontline, standard-of-care cytotoxic chemotherapy regimens produce minimal benefit in patients with metastases at presentation or those with relapsed disease. While the outcomes of chemorefractory EWS patients are generally poor, recent developments have led to the promising use of targeted therapy. Specifically, inhibition of insulin-like growth factor 1 receptor (IGF1R) signaling and the mammalian target of rapamycin (mTOR) pathways has emerged as a targeted therapy in EWS, with select patients experiencing dramatic therapeutic responses. However, targeted therapies in general, and these responders in particular, are faced with the ultimate conundrum of eventual resistance. To optimize response, combining IGF1R and mTOR inhibitor-based regimens with chemotherapy in the upfront setting in newly diagnosed high-risk EWS may clarify the true benefit of IGF1R inhibitors in these patients. Another option is to explore novel targeted multikinase inhibitors and poly(ADP-ribose) polymerase (PARP) inhibitors, which have experienced a surge in supporting preclinical data. Drugs inhibiting the downstream targets of EWS/FLI1 are also in preclinical development. However, ultimately, the underlying biomarker correlates of resistance and response must be delineated along with ways to overcome them. Novel agents, together with integration of advances in multimodal approaches (including surgery and radiation), as well as offering targeted therapies early in the disease course represent new strategies for confronting the challenges of EWS.
| S-EPMC3893930 | biostudies-literature
Project description:The long non-coding RNA lnc277 mediates a repressive gene signature in Ewing's sarcoma and is required for oncogenesis
| PRJNA259749 | ENA
Project description:A 20-year-old female presented to the Pulmonary Medicine Department with complaints of fever, left sided chest pain and progressive dyspnoea of four months duration. Radiological examination revealed a mass lesion with massive pleural effusion and rib erosion. Histopathology showed neoplastic cells with scanty cytoplasm, hyperchromatic nuclei and rosette formation suggestive of Ewing sarcoma. The rarity of this tumor and its unusual presentation prompted this report.
| S-EPMC3215445 | biostudies-other