Chromatin immunoprecipitation followed by sequencing (ChIP-seq) data for FLI1 and histone marks from EwS cell lines demonstrated that EWSR1-FLI1 binds to a GGAA-microsatellite close to CALCB, which exhibits characteristics of an active enhancer.
Ewing sarcoma is consistently associated with chromosomal translocation and functional fusion of the EWSR1 gene to any of several structurally related transcription factor genes of the E26 transformation-specific family.
Trib1 and Nrg1 were demonstrated as target genes that are co-regulated by EWS-FLI1 and Foxq1, and are important for cell proliferation and survival of Ewing sarcoma.
The results indicated that Notch1 and its target genes, Hes family BHLH transcription factor 1 and Hes‑related family BHLH transcription factor with YRPW motif 1, were suppressed by miR‑34b directly In conclusion, EWS‑FLI1 may modulate miR‑34b expression directly or indirectly, and miR‑34b potentially has an oncogenic role in Ewing's sarcoma by downregulating Notch1.
Using CRISPR-mediated epigenome editing, repression of EWS-FLI1 targeted microsatellite enhancers halted aberrant gene expression and impaired the growth of Ewing sarcoma xenografts in vivo.
EWS/FLI1 and EWS/ERG were found in a transcriptional complex with BRD4, and knockdown of BRD2/3/4 significantly impaired the oncogenic phenotype of EWS cells.
Interestingly, we found a significant overlap of PPP1R1A-regulated gene set with that of ZEB2 and EWS, which regulates metastasis and neuronal differentiation in ES, respectively.
We report a surgical case of 51-year-old woman with myoepithelioma occurring in the posterior mediastinum that harbored the Ewing sarcoma breakpoint region1 (EWSR1) gene rearrangement.
In this study, a broad range of 3,325 experimental compounds, among them FDA approved drugs and natural products, were screened for their effect on EwS cell viability depending on EWS-FLI1 expression.
Our findings improve the current understanding of EWSR1 function, elucidate the mechanistic basis of the sensitivity of Ewing sarcoma to chemotherapy (including PARP1 inhibitors) and highlight a class of BRCA-deficient-like tumours.
Pathologic analysis revealed a diagnosis of Ewing sarcoma based on the characteristic immunohistochemistry and the presence of EWSR1-FLI1 fusion transcript by reverse-transcription polymerase chain reaction.
The role of EWS-FLI1 as a driver of proliferation and transformation in ES is widely known, but the effect of epigenetic drugs on fusion activity remains poorly described.
On balance, if the following features are seen: (1) a small round blue cell tumor with histomorphology more atypical than that of Ewing sarcoma, (2) cytoplasmic CD99 staining, nuclear WT1 positivity, negative keratin, desmin and myogenin; and (3) EWSR1 rearrangement negative by FISH, then molecular testing for CIC-DUX4 sarcoma should be considered.
In this study, to identify the regulated proteins associated with EWS/FLI1 and therapeutic targets in ES, we conducted proteomic studies using EWS/FLI1 knockdown in four Ewing's sarcoma cell lines and human mesenchymal stem cells (hMSCs) expressing EWS/FLI1.
Collectively, we show that <i>ATP1A1</i>, <i>BCL11B</i>, and <i>GLG1</i> are EWSR1-FLI1 targets, of which BCL11B and GLG1 offer a fast, simple, and cost-efficient way to diagnose Ewing sarcoma by immunohistochemistry.
Importantly, analysis of EWS primary tumor transcriptome data confirmed that the aforementioned genes we identified as regulated by EWS-FLI1 exhibit increased expression compared with normal tissues.
This case highlights the distinctive clinicopathological characteristics of EWSR1-NFATC2 gene fusion-associated neoplasms that distinguish them from Ewing sarcoma.
AES has mixed features of Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET) and adamantinoma with a complex immunoprofile and EWSR1 gene rearrangements.
The present study suggested that CPX treatment may inhibit Ewing sarcoma (ES) progression through Ewing sarcoma breakpoint region 1‑Friend leukemia integration 1 (EWS‑FLI1), a common fusion transcript structure in patients with ES.