Epigenetic and Transcriptional Signaling in Ewing Sarcoma—Disease Etiology and Therapeutic Opportunities

Abstract

Ewing sarcoma (EwS), a type of bone and soft tissue tumor, is mainly driven by the expression of the fusion protein EWSR1-FLI1. Upon binding to chromatin, EWSR1-FLI1 reprograms the epigenetic state, alters gene expression, and thus leads to tumorigenesis. Considerable studies have investigated the epigenomic and transcriptomic profiling of EwS. Nevertheless, a comprehensive view of therapeutic targets is still lacking. This review discusses the epigenetic and transcriptional alterations reported in EwS. Specifically, we discuss the binding characteristics of EWSR1-FLI1 on chromatin, the mechanisms of EWSR1-FLI1 in reprograming epigenome, and EWSR1-FLI1-induced transcriptional alterations. Moreover, we summarize the chemical, RNAi, and CRISPR-cas9 high throughput screens conducted in EwS with the goal of assisting in the development of novel therapies to treat this aggressive disease.

Keywords

• Ewing sarcoma
• fusion protein
• EWSR1-FLI1
• EWS-FLI1
• epigenetic regulation
• transcriptional regulation