Project description:This study profiles chromatin accessibility, gene expresison, transcription factor binding, and three-dimensional DNA-DNA contact changes upon rapid SWI/SNF ATPase inactivation in prostate cancer cells. SWI/SNF ATPases activity was disabled using a novel PROTAC degrader compound targeting the SMARCA2, SMARCA4 and PBRM1 subunits of the SWI/SNF remodeling complex.
Project description:This study profiles chromatin accessibility, gene expresison, transcription factor binding, and three-dimensional DNA-DNA contact changes upon rapid SWI/SNF ATPase inactivation in prostate cancer cells. SWI/SNF ATPases activity was disabled using a novel PROTAC degrader compound targeting the SMARCA2, SMARCA4 and PBRM1 subunits of the SWI/SNF remodeling complex.
Project description:This study profiles chromatin accessibility, gene expresison, transcription factor binding, and three-dimensional DNA-DNA contact changes upon rapid SWI/SNF ATPase inactivation in prostate cancer cells. SWI/SNF ATPases activity was disabled using a novel PROTAC degrader compound targeting the SMARCA2, SMARCA4 and PBRM1 subunits of the SWI/SNF remodeling complex.
Project description:This study profiles chromatin accessibility, gene expresison, transcription factor binding, and three-dimensional DNA-DNA contact changes upon rapid SWI/SNF ATPase inactivation in prostate cancer cells. SWI/SNF ATPases activity was disabled using a novel PROTAC degrader compound targeting the SMARCA2, SMARCA4 and PBRM1 subunits of the SWI/SNF remodeling complex.
Project description:The mechanism controlling the dynamic targeting of SWI/SNF has long been postulated to be coordinated by transcription factors (TFs), yet identifying and demonstrating the influence of different TFs has proven difficult. In this study we take a multi-omics approach to directly interrogate transient SWI/SNF interactors, chromatin targeting, and the plasticity of the resulting 3D epigenetic landscape. We utilized the novel proximity based labeling technique TurboID to identify the AP1 family as a critical interacting partner for endogenous SWI/SNF complexes. Validation through CUT&RUN profiling demonstrated SWI/SNF targeting enrichment at AP1 bound loci, and SWI/SNF – AP1 cooperation in chromatin targeting. Mapping of 3D chromatin structure via HiChIP revealed AP1-SWI/SNF dependent restructuring of promoter-enhancer architecture and generation of enhancer hubs, ultimately regulating transcription. Through direct interrogation of the SWI/SNF – AP1 interaction, we demonstrate a SWI/SNF functional dependency on AP1 mediated chromatin localization. We propose that pioneer factors such as AP1 bind and target SWI/SNF to inactive chromatin, where it restructures the genomic landscape into an active state through epigenetic rewiring spanning multiple dimensions.
Project description:Diffuse midline gliomas (DMGs), including diffuse intrinsic pontine gliomas (DIPGs), bearing lysine-to-methionine mutations in histone H3 at lysine 27 (H3K27M) are lethal childhood brain cancers. These tumors harbor a global reduction in the transcriptional repressive mark H3K27me3 accompanied by an increase in the transcriptional activation mark H3K27ac. We postulated that H3K27M mutations, in addition to altering H3K27 modifications, reprogram the master chromatin remodeling SWI/SNF complex. The SWI/SNF complex can exist in two main forms termed BAF and PBAF that play central roles in neurodevelopment and cancer. Moreover, BAF antagonizes PRC2, the main enzyme catalyzing H3K27me3. We demonstrate that H3K27M gliomas show increased protein levels of the SWI/SNF complex ATPase subunits SMARCA4 and SMARCA2 and the PBAF component PBRM1. Additionally, knockdown of mutant H3K27M lowered SMARCA4 protein levels. The proteolysis targeting chimera (PROTAC) AU-15330 that simultaneously targets SMARCA4, SMARCA2, and PBRM1 for degradation exhibits cytotoxicity in H3.3K27M but not H3 wild-type cells. AU-15330 lowered chromatin accessibility measured by ATAC-seq at non-promoter regions and reduced global H3K27ac levels. Integrated analysis of gene expression, proteomics, and chromatin accessibility in AU-15330-treated cells demonstrated reduction in levels of FOXO1, a key member of the forkhead family of transcription factors. Moreover, genetic or pharmacologic targeting of FOXO1 resulted in cell death in H3K27M cells. Overall, our results suggest that H3K27M upregulates SMARCA4 levels and combined targeting of SWI/SNF ATPases in H3.3K27M can serve as a potent therapeutic strategy for these deadly childhood brain tumors.