Identification of chromatin regulatory sites in conditions of basal and increased SF-1 dosage in the H295R adrenocortical tumor cell line
Ontology highlight
ABSTRACT: The goal of this study was to identify chromatin regulatory sites by FAIRE-seq under conditions of basal and increased dosage of transcription factor SF-1 in the H295R human adrenocortical tumor cell line. 4 samples: input DNA in basal SF-1 expression conditions - FAIRE-seq in basal SF-1 expression conditions - input DNA in SF-1 overexpression conditions - FAIRE-seq in SF-1 overexpression conditions
Project description:The goal of this study was to identify genomic binding sites of the NRSF/REST transcription factor under conditions of basal and increased SF-1 dosage in the H295R human adrenocortical tumor cell line. 4 samples: input DNA (2 replicates) - NRSF/REST ChIP basal SF-1 dosage - NRSF/REST ChIP increased SF-1 dosage
Project description:Poor outcomes in diabetic patients are observed across a range of human tumors, suggesting that cancer cells develop unique characteristics under diabetic conditions. Cancer cells exposed to hyperglycemic insults acquire permanent aggressive traits of tumor growth, even after a return to euglycemic conditions. Comparative genome-wide mapping of hyperglycemia-specific open chromatin regions and concomitant mRNA expression profiling revealed that neuregulin-1 gene, an established endogenous ligand for the HER3 receptor, is activated through a putative distal enhancer. Our findings highlight the targeted inhibition of NRG1-HER3 pathways as a potential target for the treatment breast cancer patients with associated diabetes Chromatin was extracted from hyperglycemic (HyG) and euglycemic (Control) cancer cells; FAIRE DNA and input DNA from each sample were used to generate libraries for single end sequencing on the the SOLiD 4 HQ system
Project description:We report the open chromatin landscape in primary human macrophages and foam cells using FAIRE-seq CD14+ monocytes were isolated from the blood of 3 healthy volunteers. Monocytes were differentiated into macrophages by culture for 7 days with 50ng/ml macrophage colony stimulating factor and then treated for 48 hours with either oxidized low density lipoprotein (oxLDL) to induce foam cell formation or with a control buffer that lacked oxLDL. The resulting six samples were then subjected to FAIRE-seq using an established protocol (Simon JM, Giresi PG, Davis IJ, Lieb JD. Using formaldehyde-assisted isolation of regulatory elements (FAIRE) to isolate active regulatory DNA. Nature protocols 2012;7:256-67).
Project description:SF-1 is a nuclear receptor transcription factor playing a key role in adrenogonadal development and in adrenocortical tumorigenesis when overexpressed. NRSF/REST is a transcriptional repressor that represses expression of neuronal genes in non-neural tissues. Some data suggest that SF-1 and NRSF/REST can functionally interact in adrenocortical cancer cells. We studied gene expression profiles using Affymetrix microarrays in the H295R/TR SF-1 adrenocortical cancer cell line. In this cell line, SF-1 expression can be increased in a doxycycline-dependent manner (Mol. Endocrinol. 21: 2968–2987, 2007). The effects of a control siRNA and sRNAs specific for SF-1 and for NRSF/REST (in basal or increased SF-1 expression conditions) on gene expression were measured. In H295R/TR SF-1 cells SF-1 and NRSF/REST (in conditions of basal and increased SF-1 dosage) expression were knocked down by Amaxa nucleofection. RNA was extracted and hybridized to Human Gene 1.0 ST Affymetrix microarrays.
Project description:SF-1 is a nuclear receptor transcription factor playing a key role in adrenogonadal development and in adrenocortical tumorigenesis when overexpressed. We studied gene expression profiles using Affymetrix microarrays in the H295R/TR SF-1 adrenocortical cancer cell line, where SF-1 expression can be increased in a doxycycline-dependent manner (Mol. Endocrinol. 21: 2968–2987, 2007) H295R/TR SF-1 cells were cultured either in basal conditions or with doxycycline (Dox) added to the culture medium for 72 hours. RNA was extracted and hybridized to HG-U133 Plus 2.0 Affymetrix microarrays.
Project description:The goal of this study was to identify chromatin regulatory sites by FAIRE-seq under conditions of basal and increased dosage of transcription factor SF-1 in the H295R human adrenocortical tumor cell line.
Project description:Using the estrogen receptor alpha (ERalpha) as a model ligand inducible transcription factor, we sought to explicitly define parameters that determine transcription factor binding site selection on a genomic scale in an inducible system that minimizes confounding chromatin effects by the transcription factor itself. By examining several genetic and epigenetic parameters, we find that an energetically favorable estrogen response element (ERE) motif sequence, evidence of occupancy of a "pioneering" transcription factor FOXA1, the presence of the enhancer mark, H3K4me1, and an open chromatin configuration (FAIRE) at the pre-ligand state provide specificity for ER binding. Genome-wide ChIP-sequencing was done in MCF-7 cancer cell line for the following histone H3 modifications: monomethylation H3K4me1, trimethylation H3K4me3, H3K9me3, H3K27me3, acetylation H3K9ac, H3K14ac. In addition sequencing of RNA Pol II was done at same treatment conditions (E2 and DMSO). In addition, we assessed the chromatin configuration of ERα binding sites by deeply sequencing fragments isolated by Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) (Giresi et al, 2007) which enriches for nucleosome free genomic DNA in the aqueous phase of a phenol extraction. The analysis histone modifications in MCF-7 cancer cells was done by ChIP-seq data obtained either with E2 stimulation or without stimulation using vehicle as a control. Using the ERα binding sites defined by ChIP-seq (separate submission), we analyzed the population characteristics of the chromatin configuration of the ERα binding sites. To this end, we performed ChIP-seq analysis for the occupancy configuration of each of the following marks before and after E2 exposure: RNA Pol II, the activation marks H3K4me1, H3K4me3, H3K9ac and H3K14ac, and the repression marks H3K9me3 and H3K27me3. We assessed the chromatin configuration of ERα binding sites by deeply sequencing fragments isolated by Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) (Giresi et al, 2007) which enriches for nucleosome free genomic DNA in the aqueous phase of a phenol extraction. The tag count of FAIRE fragments reflects the nucleosome depletion at any given site. RNA Pol II - Cat# ab5408, Abcam; H3K9me3 - Cat# ab8898, Abcam; H3K27me3 - Cat# 07-449, Upstate Biotechnology Inc.; H3K4me1 - Cat# ab8895, Abcam; H3K4me3 - Cat# ab8580, Abcam; H3K9ac - Cat# 07-352, Upstate Biotechnology Inc.; H3K14ac - Cat# 07-353, Upstate Biotechnology Inc.