GSE137561
Desmoplastic small round cell tumor is dependent on EWS-WT1
Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive soft tissue malignancy. The disease is defined by the oncogenic EWS-WT1 transcription factor. However, the dependence of the tumor on this target has not been well-established and no EWS-WT1 targeted therapy has translated to the clinic.  In this report we establish the dependence of DSRCT on EWS-WT1 as well as define a gene signature and a comprehensive list of downstream targets. The selective silencing of EWS-WT1 leads to the marked suppression of proliferation of both JN-DSRCT1 and BER cells. Loss of the fusion protein results in morphologic changes in the cells and eventual cellular apoptosis. RNA sequencing demonstrates large scale gene expression changes attributable to EWS-WT1 with several hundred induced or repressed downstream targets of the fusion. We conclude DSRCT is dependent on the EWS-WT1 transcription factor for cell survival. The presence of EWS-WT1 leads to enrichment of genes involved in aberrant cell differentiation and development as well as those involved in tumor metastasis. Overall design: Three biological replicates per treatment were sequenced; mRNA was isolated individually from each replicate.