Project description:Background: Disruptions of 3D chromatin architecture can alter the activity of topologically associated domains (TADs), rewire enhancer-promoter interactions and thus significantly impact gene regulatory programs. Recently, such disruptions have been implicated in tumorigenesis, highlighting the need for a deeper understanding of their detailed role. Methods: T-ALL primary samples and prototypical cell lines as well as healthy T cell counterparts were profiled by in-situ Hi-C, RNA-Seq and CTCF ChIP-Seq. Data was subsequently integrated. Results: Our studies showed that the genome of leukemia cells does not display global changes in TAD structures but presents local changes in selected TAD boundaries as well as alterations of intra-TAD activity which are associated with changes in gene expression of key oncogenes and tumor suppressors, strong correlation with CTCF-mediated insulation and enhancer activity. Finally, we showed that 3D interactions on selected loci can be partially corrected pharmacologically, potentially accounting for the anti-leukemogenic effects of these drugs. Conclusions: Our studies underscore the need for further investigation of factors that rewire long range interactions especially during tumorigenesis, as they could be targets for pharmacological targeting.

2019-08-04 | GSE134762 | GEO

Dynamic 3D chromosomal landscapes in acute leukemia [WGS]

Project description:Background: Disruptions of 3D chromatin architecture can alter the activity of topologically associated domains (TADs), rewire enhancer-promoter interactions and thus significantly impact gene regulatory programs. Recently, such disruptions have been implicated in tumorigenesis, highlighting the need for a deeper understanding of their detailed role. Methods: T-ALL primary samples and prototypical cell lines as well as healthy T cell samples were profiled by in-situ Hi-C, RNA-Seq, CTCF ChIP-Seq and suuported by matching WGS of three primary T-ALL samples. Data was subsequently integrated. Results: Our studies showed that the genome of leukemia cells does not display global changes in TAD structures but presents local changes in selected TAD boundaries as well as alterations of intra-TAD activity which are associated with changes in gene expression of key oncogenes and tumor suppressors, strong correlation with CTCF-mediated insulation and enhancer activity. Finally, we showed that 3D interactions on selected loci can be partially corrected pharmacologically, potentially accounting for the anti-leukemogenic effects of these drugs. Conclusions: Our studies underscore the need for further investigation of factors that rewire long range interactions especially during tumorigenesis, as they could be targets for pharmacological targeting.

2019-10-29 | GSE139449 | GEO

Cooperation of chromatin remodeling SWI/SNF complex and pioneer factor AP1 shapes 3D enhancer landscapes [HiChIP]

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.

2022-10-17 | GSE175529 | GEO

Dynamic 3D chromosomal landscapes in acute leukemia [Hi-C]

2019-08-04 | GSE134761 | GEO