Chen, ChangminWonsey, Diane R.Lemieux, Madeleine E.Kung, Andrew L.2014-02-182013Chen, Changmin, Diane R. Wonsey, Madeleine E. Lemieux, and Andrew L. Kung. 2013. “Differential Disruption of EWS-FLI1 Binding by DNA-Binding Agents.” PLoS ONE 8 (7): e69714. doi:10.1371/journal.pone.0069714. http://dx.doi.org/10.1371/journal.pone.0069714.1932-6203http://nrs.harvard.edu/urn-3:HUL.InstRepos:11717615Fusion of the EWS gene to FLI1 produces a fusion oncoprotein that drives an aberrant gene expression program responsible for the development of Ewing sarcoma. We used a homogenous proximity assay to screen for compounds that disrupt the binding of EWS-FLI1 to its cognate DNA targets. A number of DNA-binding chemotherapeutic agents were found to non-specifically disrupt protein binding to DNA. In contrast, actinomycin D was found to preferentially disrupt EWS-FLI1 binding by comparison to p53 binding to their respective cognate DNA targets in vitro. In cell-based assays, low concentrations of actinomycin D preferentially blocked EWS-FLI1 binding to chromatin, and disrupted EWS-FLI1-mediated gene expression. Higher concentrations of actinomycin D globally repressed transcription. These results demonstrate that actinomycin D preferentially disrupts EWS-FLI1 binding to DNA at selected concentrations. Although the window between this preferential effect and global suppression is too narrow to exploit in a therapeutic manner, these results suggest that base-preferences may be exploited to find DNA-binding compounds that preferentially disrupt subclasses of transcription factors.en-USBiologyBiochemistryProteinsDNA-binding proteinsChemical BiologyDrug DiscoverySmall MoleculesBiotechnologyChemistryOrganic ChemistryOrganic CompoundsMedicineDrugs and DevicesDrug Research and DevelopmentOncologyCancer TreatmentChemotherapy and Drug TreatmentBasic Cancer ResearchOncology AgentsPediatric OncologyJournal Article2014-02-1810.1371/journal.pone.0069714