Heat Shock Transcription Factor 1 Facilitates Liver Cancer Progression by Driving Super-Enhancer-Mediated Transcription of MYCN
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE274408 | GEO | 2024/09/04
REPOSITORIES: GEO
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Project description:MYCN amplification in neuroblastoma leads to aberrant expression of MYCN oncoprotein, which binds active genes promoting transcriptional amplification. Yet how MYCN coordinates transcription elongation to meet productive transcriptional amplification and which elongation machinery represents MYCN-driven vulnerability remain to be identified. We conducted a targeted screen of transcription elongation factors and identified the super elongation complex (SEC) as a unique vulnerability in MYCN-amplified neuroblastomas. MYCN directly binds EAF1 and recruits SEC to enhance processive transcription elongation. Depletion of EAF1 or AFF1/AFF4, another core subunit of SEC, leads to a global reduction in transcription elongation and elicits selective apoptosis of MYCN-amplified neuroblastoma cells. A combination screen reveals SEC inhibition synergistically potentiates the therapeutic efficacies of FDA-approved BCL2 antagonist ABT-199, in part due to suppression of MCL1 expression, both in MYCN-amplified neuroblastoma cells and in patient-derived xenografts. These findings identify disruption of the MYCN-SEC regulatory axis as a promising therapeutic strategy in neuroblastoma.
2023-05-10 | PXD039332 | Pride
Project description:Despite its pivotal roles in biology, how the transcriptional activity of c-MYC is attuned quantitatively remain poorly defined. Here, we show that heat shock factor 1 (HSF1), the master transcriptional regulator of the heat-shock response, acts as a key modifier of the c-MYC-mediated transcription. HSF1 deficiency diminishes c-MYC DNA binding and dampens its transcriptional activity genome-widely. Mechanistically, c-MYC, MAX, and HSF1 assemble into a transcription factor complex on DNAs and, surprisingly, the DNA binding of HSF1 is dispensable. Instead, HSF1 physically recruits the histone acetyltransferase GCN5, thereby promoting histone acetylation and augmenting c-MYC transcriptional activity. Thus, our studies reveal that HSF1 specifically potentiates the c-MYC-mediated transcription, distinct from its role in the canonical heat-shock response. Importantly, this mechanism of action engenders two distinct c-MYC activation states, primary and advanced, which may be important to accommodate diverse physiological and pathological conditions.
2023-05-22 | GSE199462 | GEO
Project description:Transcriptional induction of Heat Shock Protein (HSP) genes in yeast is accompanied by dynamic changes in their 3D structure and spatial organization, yet the molecular basis for these phenomena remains unknown. Using chromosome conformation capture and single cell imaging, we show that genes transcriptionally activated by Heat Shock Factor 1 (Hsf1) specifically interact across chromosomes and coalesce into diffraction-limited intranuclear foci. Genes activated by the alternative stress regulators Msn2 and Msn4, in contrast, do not interact among themselves nor with Hsf1 targets. Likewise, constitutively expressed genes, even those interposed between HSP genes, show no detectable interaction. Hsf1 forms discrete subnuclear puncta when stressactivated, and these puncta dissolve in concert with transcriptional attenuation, paralleling the kinetics of HSP gene coalescence and dissolution. Nuclear Hsf1 and RNA Pol II are both necessary for intergenic HSP gene interactions, while DNA-bound Hsf1 is necessary and sufficient to drive coalescence of a heterologous gene. Our findings demonstrate that Hsf1 can dynamically restructure the yeast genome.
2018-11-20 | GSE122666 | GEO
Project description:HSF1 binds DNA via the DBD domain, causing gene upregulation during HS. We assessed the effect of RD-mediated phase separation on chromatin targeting of HSF1 using Cut&Tag followed by high-throughput sequencing to map genome-wide binding of LLPS-competent versus LLPS-incompetent HSF1 mutants under both HS and NHS conditions. Comparing with WT HSF1 under NHS, both WT under HS and M1 under NHS showed increased and broad binding to enhancers and distal intergenic region, with binding most enriched in expected motifs of HSF-related transcription factors. To further assess the role for IDR-induced LLPS in chromatin targeting of HSF1, we used several additional strategies. First, the treatment of 1,6-hexanediol markedly decreased chromatin occupancy both of WT under HS and M1 under NHS conditions. Second, we interrogate chromatin binding of LLPS-deficient mutant M3. Cut&Tag analysis revealed that M3 showed decreased chromatin binding compared to WT under HS and M1 under NHS. The decreased chromatin binding of M3 to chromatin was not due to the loss of its DNA binding ability, as the EMSA assay revealed that M3 was still capable of binding HSE. Instead, the decreased chromatin binding reflects the loss of inter-molecular interaction between HSF1 that holds LLPS. Furthermore, M3 in heat shocked cells shows similar reduced genomic targeting and shallow binding pattern as NHS cells . Third, the enrichment of transcriptional apparatus RNA Pol II, CYCT1, BRD4 to HSF1 target genes also depend on whether HSF1 can phase separate at these sites. Lastly, we conducted live cell single molecule imaging to evaluate chromatin binding kinetics of LLPS-deficient mutant M3 relative to WT HSF1. Measurements of single molecule displacement and diffusion coefficient showed M3 to be significantly more mobile than WT under HS, which suggests M3 was less confined within phase-separated puncta compared with LLPS-competent HSF1. Consistent with this result, super resolution imaging of M3 also showed decreased cluster formation at HSP gene foci but maintained nSBs formation. Altogether, LLPS-forming capability of HSF1 is essential for the efficient recruitment of HSF1 and transcriptional apparatus to HSP gene loci.
2021-12-24 | GSE192370 | GEO
Project description:Mouse HSF1+/+ and HSF1-/- Fibroblasts Heat Shock Time Courses Scanned on Scanner 7 (Axon 4000B) Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-08-05 | GSE3074 | GEO
Project description:MYCN amplification (MNA) is a defining feature of high-risk neuroblastoma (NB) that predicts poor prognosis. However, whether genes within or in close proximity to the MYCN amplicon also contribute to aggressiveness in MNA+ NB remains poorly understood. Here we identify that GREB1, a transcription factor encoding gene neighboring the MYCN locus, is frequently co-expressed with MYCN, and promotes cell survival in MNA+ NB. GREB1 controls gene expression independently of MYCN in MNA+ NB, among which we uncover Myosin 1B (MYO1B) as being highly expressed in MNA+ NB. MYO1B promotes aggressive features, including invasive capacity in vitro, as well as extravasation and distant metastasis in vivo. Global secretome and proteome profiling further delineate MYO1B as a major regulator of secretome reprogramming in MNA+ NB cells. Moreover, we identify the cytokine MIF as an important pro-invasive and pro-metastatic mediator of MYO1B activity. Together, we have identified a putative GREB1-MYO1B-MIF axis as an unconventional mechanism that promotes the aggressiveness of MNA+ NB, and independently of MYCN. Furthermore, we find that MYO1B is upregulated in association with other oncoproteins during cellular transformation, and is dramatically increased in multiple human cancer types, suggesting a crucial role of MYO1B in cancers in addition to MNA+ NB.
2023-10-24 | PXD039410 | Pride
Project description:We investigated whether interfering with HSF1 LLPS affected the expression of its target genes using RNA sequencing. We found HS induced HSPs gene expression in LLPS-dependent manner. LLPS-dependent gene activation was also observed in M1 cells under NHS condition. In addition, LLPS-incompetent M3 infected cells showed less HSP gene expression even under HS condition. Thus, these data collectively support a crucial role for LLPS of HSF1 in activating HSP genes expression.
2021-12-19 | GSE191134 | GEO
Project description:Mouse HSF1+/+ and HSF1-/- Fibroblasts Heat Shock Time Courses Scanned on Scanner 7 (Axon 4000B)
2005-07-21 | E-SMDB-1853 | biostudies-arrayexpress
Project description:In cells derived from a genetically engineered Rb1 and Trp53 loss mouse model of SCLC (RP) expression of one of the three MYC family members induced from the endogenous locus using CRISPR activation. Cells were first stably transfected with the lenti-MS2-p65-HSF1 activator plasmid. Respective sgRNAs targeting either Myc, Mycl or MYCN were then cloned into the lentiSAMv2 system and transfected separately into the MS2-p65-HSF1 cells using lentiviral delivery.
2019-07-09 | E-MTAB-7411 | biostudies-arrayexpress
Project description:Heat shock response (HSR) is critical for survival of organisms undergoing proteotoxic stress. Heat shock factor 1 (HSF1) is widely believed to be the master regulator of this response. Here, we examined the kinetics of the transcriptional response and HSF1 binding changes genome-wide after heat shock (HS) with high sensitivity and high spatial and temporal resolution using PRO-seq and ChIP-seq assays respectively in wild type and in hsf1-deletion mouse embryonic fibroblasts. The transcriptional response is rapid, dynamic, and extensive with activation of several hundred genes and repression of several thousands of genes. Although HSF1 is critically required for classical inducible Heat Shock Protein (HSP) genes, it is not required for the majority of gene activation. HSF1 acts mechanistically to promote RNA polymerase II (Pol II) release from the promoter-proximal pause, while recruitment and initiation of Pol II are predominantly HSF1-independent. Surprisingly, a major class of cytoskeleton genes is immediately (within 2.5 minutes) and transiently activated in an HSF1-independent manner. A second wave of regulation is characterized by robust activation or repression of new sets of genes. The broad repression of thousands of genes, a quarter of which are repressed immediately upon HS and the rest are repressed in the second wave of regulation, is mediated at the level of decreasing Pol II pause release and not at prior steps of Pol II recruitment or initiation. Notably, heat shock does not induce transcription of some previously defined HSP genes, and HSF2 â a homolog of HSF1 â does not compensate for the lack of HSF1. Together, these findings indicate that mammalian cells cope with stress by rapidly inducing pervasive and dramatic changes in transcription that are largely modulated at the step of pause release, and only a fraction of this regulation is HSF1-dependent. Examination of transcriptional regulation before and after heat shock in WT, HSF1-/-, and HSF1&2-/- MEFs
2016-03-01 | E-GEOD-71708 | biostudies-arrayexpress