Project description:Transcriptomic analysis of the well-characterized Ewing sarcoma cell line A673 indicated that one of the genes more strongly upregulated by EWSR1-FLI1 was FEZF1 (FEZ family zinc finger protein 1), a transcriptional repressor involved in brain development and neural cell identity. FEZF1 was highly expressed in Ewing sarcoma cells but not in other bone tumors such as osteosarcoma or chondrosarcoma. FEZF1 promoter contains a large GGAA-microsatellite and the number of GGAA repeats correlated positively with FEZF1 expression levels in Ewing sarcoma cell lines. To characterize the functional role of FEZF1 in Ewing sarcoma we analyzed the effect of FEZF1 knockdown in three Ewing sarcoma cell lines (A673, SKNMC, SKES1). FEZF1 knockdown inhibited clone formation in clonogenic assays and cell proliferation. Finally, we analyzed the FEZF1-dependent expression profile in A673 cells by RNAseq. Interestingly, several neural genes regulated by FEZF1 were concomitantly regulated by EWSR1-FLI1. In summary, FEZF1 is a transcriptional target of EWSR1-FLI1 in Ewing sarcoma cells involved in the regulation of neural-specific genes which could explain, at least in part, the neural-like phenotype observed in several Ewing sarcoma tumors and derived cell lines.
Project description:EWS-FLI1, a multi-functional fusion oncogene, is exclusively detectable in Ewing sarcomas. However, previous studies reported that a subset of osteosarcomas also harbor EWS-ETS family fusion, suggesting that the fusion gene may be involved in the development of a particular type of osteosarcomas. Here using the doxycycline inducible EWS-FLI1 system, we established an EWS-FLI1-dependent osteosarcoma model from murine bone marrow stromal cells. We revealed that the withdrawal of EWS-FLI1 expression enhances the osteogenic differentiation of sarcoma cells, leading to mature bone formation. Taking advantage of induced pluripotent stem cell (iPSC) technology, we also showed that the sarcoma-derived iPSCs with cancer-related genetic abnormalities exhibited the impaired differentiation program of osteogenic lineage irrespective of the EWS-FLI1 expression. Finally, we demonstrated that EWS-FLI1 contributed to in vitro sarcoma development from the sarcoma-iPSCs after osteogenic differentiation. These findings demonstrated that modulating cellular differentiation is fundamental principle of the EWS-FLI1-induced osteosarcoma development. Furthermore, the in vitro cancer model using sarcoma-iPSCs should provide a novel platform for dissecting relationship between cancer genome and cellular differentiation. Chip-seq in mouse EWS-FLI1-induced osteosarcoma cell lines (SCOS#2 )
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:Ewing sarcoma is one of the solid tumor that developed in children. We performed SNP-chip analysis against 27 specimens of Ewing sarcoma using Affymetrix GeneChip and CNAG/AsCNAR software. Our study revealed the detailed profile of copy number alterations in Ewing sarcoma. Keywords: SNP-chip To identify oncogenic lesions in Ewing sarcoma, we performed a genome-wide analysis of Ewing sarcoma samples using high-density SNP arrays (Affymetrix GeneChip).
