Selective Disruption of Core Regulatory Transcription [RNA-seq]
Ontology highlight
ABSTRACT: Activation of identity determining transcription factors (TFs), or core regulatory TFs, is governed by cell-type specific enhancers, an important subset of these being super enhancers (SEs). This mechanism is distinct from constitutive expression of housekeeping genes. The characterization of drug-like small molecules to selectively inhibit core regulatory circuitry is of high interest for treatment of cancers, which are addicted to core regulatory TF function at SEs. Surprisingly, we find histone deacetylases (HDAC) to be an indispensable component of SE-driven transcription. While histone acetylation is a marker for active genes, over accumulation of acetylation selectively halts core regulatory transcription. We show this conundrum may in part be explained by a SE-specific need for resetting histones to maintain SE boundaries, to facilitate enhancer-promoter looping and high levels of transcription.
Project description:Activation of identity determining transcription factors (TFs), or core regulatory TFs, is governed by cell-type specific enhancers, an important subset of these being super enhancers (SEs). This mechanism is distinct from constitutive expression of housekeeping genes. The characterization of drug-like small molecules to selectively inhibit core regulatory circuitry is of high interest for treatment of cancers, which are addicted to core regulatory TF function at SEs. Surprisingly, we find histone deacetylases (HDAC) to be an indispensable component of SE-driven transcription. While histone acetylation is a marker for active genes, over accumulation of acetylation selectively halts core regulatory transcription. We show this conundrum may in part be explained by a SE-specific need for resetting histones to maintain SE boundaries, to facilitate enhancer-promoter looping and high levels of transcription.
Project description:Activation of identity determining transcription factors (TFs), or core regulatory TFs, is governed by cell-type specific enhancers, an important subset of these being super enhancers (SEs). This mechanism is distinct from constitutive expression of housekeeping genes. The characterization of drug-like small molecules to selectively inhibit core regulatory circuitry is of high interest for treatment of cancers, which are addicted to core regulatory TF function at SEs. Surprisingly, we find histone deacetylases (HDAC) to be an indispensable component of SE-driven transcription. While histone acetylation is a marker for active genes, over accumulation of acetylation selectively halts core regulatory transcription. We show this conundrum may in part be explained by a SE-specific need for resetting histones to maintain SE boundaries, to facilitate enhancer-promoter looping and high levels of transcription.
Project description:Super-enhancers (SEs) are cis-regulatory elements enriching lineage specific key transcription factors (TFs) to form hotspots. A paucity of identification and functional dissection promoted us to investigate SEs during myoblast differentiation. ChIP-seq analysis of histone marks leads to the uncovering of SEs which remodel progressively during the course of differentiation. Further analyses of TF ChIP-seq enable the definition of SE hotspots co-bound by the master TF, MyoD and other TFs, among which we perform in-depth dissection for MyoD/FoxO3 interaction in driving the hotspots formation and SE activation.
Project description:Super-enhancers (SEs) are cis-regulatory elements enriching lineage specific key transcription factors (TFs) to form hotspots. A paucity of identification and functional dissection promoted us to investigate SEs during myoblast differentiation. ChIP-seq analysis of histone marks leads to the uncovering of SEs which remodel progressively during the course of differentiation. Further analyses of TF ChIP-seq enable the definition of SE hotspots co-bound by the master TF, MyoD and other TFs, among which we perform in-depth dissection for MyoD/FoxO3 interaction in driving the hotspots formation and SE activation.
Project description:Super-enhancers (SEs) are large clusters of transcriptional enhancers that are co-occupied by multiple lineage specific transcription factors driving expression of genes that define cell identity. In embryonic stem cells (ESCs), SEs are highly enriched for Oct4, Sox2, and Nanog in the enhanceosome assembly and express enhancer RNAs (eRNAs). We sought to dissect the molecular control mechanism of SE activity and eRNA transcription for pluripotency and reprogramming. Starting from a protein interaction network surrounding Sox2, a key pluripotency and reprogramming factor that guides the ESC-specific enhanceosome assembly and orchestrates the hierarchical transcriptional activation during the final stage of reprogramming, we discovered Tex10 as a novel pluripotency factor that is evolutionally conserved and functionally significant in ESC self-renewal, early embryo development, and reprogramming. Tex10 is enriched at SEs in a Sox2-dependent manner and coordinates histone acetylation and DNA demethylation of SEs. Our study sheds new light on epigenetic control of SE activity for cell fate determination. Genome binding/occupancy profiling of Tex10 was performed in mouse embryonic stem cells by ChIP sequencing.
Project description:HAND2, MEIS2 and TCF4 are master transcription factors (TFs) in neuroblastoma and create an interconnected core regulatory circuitry (CRC) by directly occupying each other's and their own super-enhancers (SEs), which leads to high levels of each TF expression inside the CRC. Additionally, CRC TFs cooperatively co-occupy the same SE components, which promotes the expression of genes involved in cell identity and cell-type-specific activities. Super-enhancer-mediated CRC enriched at key oncogenes in neuroblastoma. In the present study, CUT&Tag (Cleavage Under Targets and Tagmentation) analysis was performed to explore the target of HAND2, MEIS2 and TCF4 in NB cells.
Project description:Super-enhancers (SEs) are large clusters of transcriptional enhancers that are co-occupied by multiple lineage specific transcription factors driving expression of genes that define cell identity. In embryonic stem cells (ESCs), SEs are highly enriched for Oct4, Sox2, and Nanog in the enhanceosome assembly and express enhancer RNAs (eRNAs). We sought to dissect the molecular control mechanism of SE activity and eRNA transcription for pluripotency and reprogramming. Starting from a protein interaction network surrounding Sox2, a key pluripotency and reprogramming factor that guides the ESC-specific enhanceosome assembly and orchestrates the hierarchical transcriptional activation during the final stage of reprogramming, we discovered Tex10 as a novel pluripotency factor that is evolutionally conserved and functionally significant in ESC self-renewal, early embryo development, and reprogramming. Tex10 is enriched at SEs in a Sox2-dependent manner and coordinates histone acetylation and DNA demethylation of SEs. Our study sheds new light on epigenetic control of SE activity for cell fate determination. RNA sequencing analysis was performed in mouse embryonic stem cells with Luciferase and Tex10 knockdown. RNA-seq Experiments were carry out in two biological replicates.
Project description:The fusion transcription factor PAX3-FOXO1 drives oncogenesis in a subset of rhabdomyosarcomas, however the mechanisms by which it remodels chromatin are unknown. We find PAX3-FOXO1 reprograms the cis-regulatory landscape by inducing super enhancers (SEs), in collaboration with master transcription factors MYOG, MYOD and MYCN. This myogenic SE circuitry is consistent across cell lines and primary tumors. Deregulation of PAX3-FOXO1 itself occurs by translocation-induced chromatin loops bringing the PAX3 promoter under the control of FOXO1 enhancers. Protein targets induced by, or bound to, PAX3-FOXO1 occupied SEs, were selectively sensitive to small molecule inhibition. PAX3-FOXO1 co-binds BRD4 at SEs, and BET bromodomains are required for PAX3-FOXO1-dependent transcription and cancer cell growth.
Project description:The fusion transcription factor PAX3-FOXO1 drives oncogenesis in a subset of rhabdomyosarcomas, however the mechanisms by which it remodels chromatin are unknown. We find PAX3-FOXO1 reprograms the cis-regulatory landscape by inducing super enhancers (SEs), in collaboration with master transcription factors MYOG, MYOD and MYCN. This myogenic SE circuitry is consistent across cell lines and primary tumors. Deregulation of PAX3-FOXO1 itself occurs by translocation-induced chromatin loops bringing the PAX3 promoter under the control of FOXO1 enhancers. Protein targets induced by, or bound to, PAX3-FOXO1 occupied SEs, were selectively sensitive to small molecule inhibition. PAX3-FOXO1 co-binds BRD4 at SEs, and BET bromodomains are required for PAX3-FOXO1-dependent transcription and cancer cell growth.
Project description:The fusion transcription factor PAX3-FOXO1 drives oncogenesis in a subset of rhabdomyosarcomas, however the mechanisms by which it remodels chromatin are unknown. We find PAX3-FOXO1 reprograms the cis-regulatory landscape by inducing super enhancers (SEs), in collaboration with master transcription factors MYOG, MYOD and MYCN. This myogenic SE circuitry is consistent across cell lines and primary tumors. Deregulation of PAX3-FOXO1 itself occurs by translocation-induced chromatin loops bringing the PAX3 promoter under the control of FOXO1 enhancers. Protein targets induced by, or bound to, PAX3-FOXO1 occupied SEs, were selectively sensitive to small molecule inhibition. PAX3-FOXO1 co-binds BRD4 at SEs, and BET bromodomains are required for PAX3-FOXO1-dependent transcription and cancer cell growth.