[PDF][PDF] EWS-FLI1 utilizes divergent chromatin remodeling mechanisms to directly activate or repress enhancer elements in Ewing sarcoma

N Riggi, B Knoechel, SM Gillespie, E Rheinbay… - Cancer cell, 2014 - cell.com
N Riggi, B Knoechel, SM Gillespie, E Rheinbay, G Boulay, ML Suvà, NE Rossetti
Cancer cell, 2014cell.com
The aberrant transcription factor EWS-FLI1 drives Ewing sarcoma, but its molecular function
is not completely understood. We find that EWS-FLI1 reprograms gene regulatory circuits in
Ewing sarcoma by directly inducing or repressing enhancers. At GGAA repeat elements,
which lack evolutionary conservation and regulatory potential in other cell types, EWS-FLI1
multimers induce chromatin opening and create de novo enhancers that physically interact
with target promoters. Conversely, EWS-FLI1 inactivates conserved enhancers containing …
Summary
The aberrant transcription factor EWS-FLI1 drives Ewing sarcoma, but its molecular function is not completely understood. We find that EWS-FLI1 reprograms gene regulatory circuits in Ewing sarcoma by directly inducing or repressing enhancers. At GGAA repeat elements, which lack evolutionary conservation and regulatory potential in other cell types, EWS-FLI1 multimers induce chromatin opening and create de novo enhancers that physically interact with target promoters. Conversely, EWS-FLI1 inactivates conserved enhancers containing canonical ETS motifs by displacing wild-type ETS transcription factors. These divergent chromatin-remodeling patterns repress tumor suppressors and mesenchymal lineage regulators while activating oncogenes and potential therapeutic targets, such as the kinase VRK1. Our findings demonstrate how EWS-FLI1 establishes an oncogenic regulatory program governing both tumor survival and differentiation.
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