Genome-wide characterization of HSF1 binding in human 451Lu melanoma cancer cells under basal conditions
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ABSTRACT: HSF1 orchestrates a transcriptional program vital for cancer cells. In this study we assayed for genome-wide localization of HSF1 enrichment in the 451Lu melanoma in untreated cells. These results revealed a transcriptional program enriched for metastasis-related genes. Twenty million cells were used for the ChIP and precipitated using 5 micrograms of antibody (cell signaling, 4356) against human HSF1
Project description:FBXW7 modulates stress response by post-translational modification of HSF1 HSF1 orchestrates the heat-shock response upon exposure to heat stress and activates a transcriptional program vital for cancer cells. In this study we assayed for genome-wide localization of HSF1 enrichment in the HCT116 FBXW7 KO colon cells and their wild type counterpart in untreated cells and upon heat shock. These results revealed that accumulation of nuclear HSF1 in FBXW7 KO cells results in rewiring of the HSF1 transcriptional program. Five million cells were used for the ChIP and precipitated using 5 micrograms of antibody (cell signaling, 4356) against human HSF1
Project description:The heat shock response is a universal transcriptional response to proteotoxic stress orchestrated by heat shock transcription factor Hsf1 in all eukaryotic cells. Despite over 40 years of intense research, the mechanism of HSF1 activity regulation remains poorly understood at a molecular level. In metazoa Hsf1 trimerizes upon heat shock through a leucin-zipper domain and binds to DNA. How Hsf1 is dislodged from DNA and monomerized remained enigmatic. Here, using purified proteins we demonstrate that unmodified trimeric Hsf1 is dissociated from DNA in vitro by Hsc70 and DnaJB1. Hsc70 binds to multiple sites in Hsf1 with different affinities. Hsf1 trimers are monomerized by successive cycles of entropic pulling, unzipping the triple leucinezipper. Starting this unzipping at several protomers of the Hsf1 trimer results in faster monomerization. This process directly monitors the concentration of Hsc70 and DnaJB1. During heat shock adaptation Hsc70 first binds to a high affinity site in the transactivation domain leading to partial attenuation of the response and subsequently, at higher concentrations, Hsc70 removes Hsf1 from DNA to restore the resting state.
Project description:T-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we assayed for genome-wide localization of JMJD3 enrichment. This piece of data was further integrated to expression changes using RNA sequencing as well as ChIP-Sequencing analysis of H3K27me3 upon genomic/genetic knock-down or chemical inhibition of JMJD3 and UTX. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to identify a hitherto unknown role of JMJD3 as an oncogenice facilitator in leukemia whereas UTX plays a tumor suppressor role. JMJD3 ChIP: 10 million cells were used for the ChIP and precipitated using 10micrograms of antibody (abgent, AP1022a) against human JMJD3.
Project description:T-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we chemically inhibited the H3K27me3 demethylase JMJD3 using the GSKJ4 inhibitor and assayed for genome-wide changes in H3K27me3 and JMJD3 enrichment. This piece of data was further integrated to expression changes using RNA sequencing as well as ChIP-Sequencing analysis of H3K27me3 upon genomic knock-down of JMJD3 and UTX. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to identify a hitherto unknown role of JMJD3 as an oncogenice facilitator in leukemia whereas UTX seems to play a tumor suppressor role. Histone ChIP: Half to one million cells were treated with micrococcal nuclease (MNASE) to generate mononucleosomal particles and an adaptation of the Upstate ChIP protocol was used.
Project description:T-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we abrogated the expression of JMJD3 (KDM6B) and UTX (KDM6A) H3K27me3 demethylases in human T-ALL lines and assayed for genome-wide changes in H3K27me3 levels. This piece of data was further integrated to expression changes using RNA sequencing in the same cells as well as ChIP-Sequencing analysis of H3K27me3 and JMJD3 genome-wide analysis from treatment of T-ALL lines with the GSKJ4 inhibitor. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to identify a hitherto unknown role of JMJD3 as an oncogenice facilitator in leukemia whereas UTX seems to play a tumor suppressor role. Half to one million cells were treated with micrococcal nuclease (MNASE) to generate mononucleosomal particles and an adaptation of the Upstate ChIP protocol was used.
Project description:Although HSF1 is known to play an important role in regulating the cellular response to proteotoxic stressors, little is known about the structure and function of the HSF1 signaling network under both stressed and unstressed conditions. In this study, we used a combination of chromatin immunoprecipitation (ChIP) microarray analysis and time course gene expression microarray analysis with and without siRNA-mediated inhibition of HSF1 comprehensively identify genes directly and indirectly regulated by HSF1 and examine the structure of the extended HSF1 signaling network. Correlation between promoter binding and gene expression was not significant for all genes bound by HSF1 suggesting that HSF1 binding per se is not sufficient for expression. However, the correlation with promoter binding was significant for genes identified as HSF1-regulated following siRNA knockdown allowing the identification of direct transcriptional targets of HSF1. Among promoters bound by HSF1 following heat shock, a gene ontology (GO) analysis showed significant enrichment only in categories related to protein folding. In contrast, analysis of the extended HSF1 signaling network showed enrichment in a variety of categories related to protein folding, anti-apoptosis, RNA splicing, ubiquitination and others, highlighting a complex transcriptional program directly and indirectly regulated by HSF1.,SUBMITTER_CITATION: Genome-wide analysis of human HSF1 signaling reveals a transcriptional program linked to cellular adaptation and survival Authors: Todd J. Page, Devanjan Sikder, Longlong Yang, Linda Pluta, Russell D. Wolfinger, Thomas Kodadek, and Russell S. Thomas Journal: Molecular Biosystems 2:627-639
Project description:Analysis of HSF1-down regulation of HCC cells at gene expression level. Results provide important information of genes involved in HSF1, such as liver proliferation, apoptosis, stress response, metabolism, these genes were up- or down-regulated. Total RNA obtained from HSF1-KD KYN2 (HCC) cells and HSF1-control KYN2 cells. To identify genes generally involved in HSF1 associated, we compared expression profiles between HSF1-KD KYN2 (HCC) cells and HSF1-control KYN2 cells by using Illumina HumanWG-6 BeadChip.
Project description:Heat-Shock Factor 1 (HSF1), master regulator of the heat-shock response, facilitates malignant transformation, cancer cell survival and proliferation in model systems. The common assumption is that these effects are mediated through regulation of heat-shock protein (HSP) expression. However, the transcriptional network that HSF1 coordinates directly in malignancy and its relationship to the heat-shock response have never been defined. By comparing cells with high and low malignant potential alongside their non-transformed counterparts, we identify an HSF1-regulated transcriptional program specific to highly malignant cells and distinct from heat shock. Cancer-specific genes in this program support oncogenic processes: cell-cycle regulation, signaling, metabolism, adhesion and translation. HSP genes are integral to this program, however, even these genes are uniquely regulated in malignancy. This HSF1 cancer program is active in breast, colon and lung tumors isolated directly from human patients and is strongly associated with metastasis and death. Thus, HSF1 rewires the transcriptome in tumorigenesis, with prognostic and therapeutic implications. ChIP-seq was used to characterize HSF1 binding