Project description:In this study, we used Global Run-On sequencing (GRO-seq), a method that assays the genome-wide location and orientation of all active RNA polymerases. We generated a global profile of active transcription at ERM-NM-1 binding sites in MCF-7 human breast cancer cells in response to short time course of E2 treatment. This method enabled us to detect active transcription at enhancers and define a class of primary transcripts transcribed uni- or bidirectionally from the ERM-NM-1 binding sites. The raw data used in this study is from GSE27463 but sequenced to a greater depth. Using GRO-seq over a time course (0, 10, 40 min) of estrogen signaling in ER-alpha positive MCF-7 human breast cancer cells.
Project description:The functional importance of gene enhancers in regulated gene expression is well established. In addition to widespread transcription of long non-coding RNA (ncRNA) transcripts in mammalian cells, bidirectional ncRNAs referred to as eRNAs are present on enhancers. However, it has remained unclear whether these eRNAs are functional, or merely a reflection of enhancer activation. Here, we report that 17 ?-estradiol (E2)-bound estrogen receptor alpha (ER?) on enhancers causes a global increase in eRNA transcription on enhancers adjacent to E2 upregulated coding genes. These induced eRNAs, as functional transcripts, appear to exert important roles for the observed ligand-dependent induction of target coding genes, causing an increased strength of specific enhancer:promoter looping initiated by ER? binding. Cohesin, present on many ER?-regulated enhancers even prior to ligand treatment, apparently contributes to E2-dependent gene activation by stabilizing E2/ER?/eRNA-induced enhancer:promoter looping. Our data indicate that eRNAs are likely to exert important functions in many regulated programs of gene transcription. The ChIP-seqs in this study measure the binding landscape of master transcription regulator of estrogen signaling - ER?, together with common histone marks including H3K27ac and H3K4me1 in MCF7 cells. These data serve as the basis to understand the enhancer map and subsequent analysis of eRNA expression using GRO-seq. The GRO-seq measures the trancription of nascent RNAs in the genome. From MCF7 cells treated with veichle or estrodial, we could identify estrogen-regulated eRNAs and subsequently could study their functions.
Project description:Differential ChIP-Seq data monitoring changes in active enhancer marks (H3K27ac sites) after treatment with siGRHL2 in MCF7 and T47D breast cancer models. Comparing sites altered by treatment with siGRHL2 after 48hours revealed these sites to be enriched for Estrogen Receptor (ER) binding.
Project description:The interplay between mitogenic and proinflammatory signaling pathways play key roles in determining the phenotypes and clinical outcomes of breast cancers. We have used global nuclear run-on coupled with deep sequencing to characterize the immediate transcriptional responses of MCF-7 breast cancer cells treated with estradiol, TNF?, or both. In addition, we have integrated these data with chromatin immunoprecipitation coupled with deep sequencing for estrogen receptor alpha (ER?), the pioneer factor FoxA1 and the p65 subunit of the NF-?B transcription factor. Our results indicate extensive transcriptional interplay between these two signaling pathways, which is observed for a number of classical mitogenic and proinflammatory protein-coding genes. In addition, GRO-seq has allowed us to capture the transcriptional crosstalk at the genomic locations encoding for long non-coding RNAs, a poorly characterized class of RNAs which have been shown to play important roles in cancer outcomes. The synergistic and antagonistic interplay between estrogen and TNF? signaling at the gene level is also evident in the patterns of ER? and NF-?B binding, which relocalize to new binding sites that are not occupied by either treatment alone. Interestingly, the chromatin accessibility of classical ER? binding sites is predetermined prior to estrogen treatment, whereas ER? binding sites gained upon co-treatment with TNF? require NF-?B and FoxA1 to promote chromatin accessibility de novo. Our data suggest that TNF? signaling recruits FoxA1 and NF-?B to latent ER? enhancer locations and directly impact ER? enhancer accessibility. Binding of ER? to latent enhancers upon co-treatment, results in increased enhancer transcription, target gene expression and altered cellular response. This provides a mechanistic framework for understanding the molecular basis for integration of mitogenic and proinflammatory signaling in breast cancer. Using GRO-seq and ChIP-seq (ER, FoxA1 and p65) to assay the molecular crosstalk of MCF-7 cells treated with E2, TNFa or both E2+TNFa.
Project description:Phosphorylation of the estrogen receptor-α (ER) at serine 118 (pS118-ER) is involved in modulating ER-dependent gene transcription and recruitment of ER to certain gene promoters. While the effects of pS118 on ER-DNA interactions have been investigated at specific sites, the genome-wide binding profile (cistrome) of pS118-ER remains to be studied. To characterize the pS118-ER cistrome, ChIP-seq was performed on pS118-ER and pan-ER in MCF-7 cells. A subset of ER sites was occupied by pS118-ER and these sites were associated with the active enhancer mark H3K27ac. Additionally, pS118-ER sites were found to be enriched in the DNA binding motif for GRHL2 as well as the estrogen response element relative to all ER sites. Utilizing a DNA binding microarray, pS118-ER was found to be more commonly associated with direct DNA binding events compared to indirect binding events. These results suggest a role for pS118-ER at active enhancers and as a regulator of direct ER-DNA interactions.
Project description:The interplay between mitogenic and proinflammatory signaling pathways play key roles in determining the phenotypes and clinical outcomes of breast cancers. We have used global nuclear run-on coupled with deep sequencing to characterize the immediate transcriptional responses of MCF-7 breast cancer cells treated with estradiol, TNFM-NM-1, or both. In addition, we have integrated these data with chromatin immunoprecipitation coupled with deep sequencing for estrogen receptor alpha (ERM-NM-1), the pioneer factor FoxA1 and the p65 subunit of the NF-M-NM-:B transcription factor. Our results indicate extensive transcriptional interplay between these two signaling pathways, which is observed for a number of classical mitogenic and proinflammatory protein-coding genes. In addition, GRO-seq has allowed us to capture the transcriptional crosstalk at the genomic locations encoding for long non-coding RNAs, a poorly characterized class of RNAs which have been shown to play important roles in cancer outcomes. The synergistic and antagonistic interplay between estrogen and TNFM-NM-1 signaling at the gene level is also evident in the patterns of ERM-NM-1 and NF-M-NM-:B binding, which relocalize to new binding sites that are not occupied by either treatment alone. Interestingly, the chromatin accessibility of classical ERM-NM-1 binding sites is predetermined prior to estrogen treatment, whereas ERM-NM-1 binding sites gained upon co-treatment with TNFM-NM-1 require NF-M-NM-:B and FoxA1 to promote chromatin accessibility de novo. Our data suggest that TNFM-NM-1 signaling recruits FoxA1 and NF-M-NM-:B to latent ERM-NM-1 enhancer locations and directly impact ERM-NM-1 enhancer accessibility. Binding of ERM-NM-1 to latent enhancers upon co-treatment, results in increased enhancer transcription, target gene expression and altered cellular response. This provides a mechanistic framework for understanding the molecular basis for integration of mitogenic and proinflammatory signaling in breast cancer. Using GRO-seq and ChIP-seq (ER, FoxA1 and p65) to assay the molecular crosstalk of MCF-7 cells treated with E2, TNFM-NM-1 or both E2+TNFM-NM-1.
Project description:To determine the role of estrogen-related receptor gamma (ERRg) in cardiac myocyte enhancers, we performed ChIP-seq studies with hiPSC-CMs using antibody directed against acetylated histone 3 at lysine residue 27 (H3K27ac), a known active enhancer mark. We found that knocking out ERRg downregulated H3K27ac depositions on several adult cardiac contractile protein and mitochondrial oxidative metabolic genes. These results establish significant roles of ERR to activate cardiac enhancer and promoter activities.
Project description:Tumor characteristics are decisive in the determination of treatment strategy for breast cancer patients. Patients with estrogen receptor a(ERa)-positive breast cancer can benefit from long-term hormonal treatment. Nonetheless, the majority of patients will develop resistance to these therapies. Here, we investigated the role of the nuclear receptor liver receptor homolog-1 (LRH-1, NR5A2) in anti-estrogen (AE) sensitive and resistant breast cancer cells. We identified genome-wide LRH-1 binding sites using ChIP-seq, uncovering preferential binding to regions distal to transcriptional start sites (TSS). We further characterized these LRH-1 binding sites by integrating overlapping layers of specific chromatin marks, revealing that many LRH-1 binding sites are active and could be involved in long-range enhancer-promoter looping. Combined with transcriptome analysis of LRH-1 depleted cells, these results show that LRH-1 regulates specific subsets of genes involved in cell proliferation in AE-sensitive and AE-resistant breast cancer cells. Furthermore, the LRH-1 transcriptional program is highly associated with a signature of poor outcome and high-grade breast cancer tumors in vivo. Herein we report the genome-wide location and molecular function of LRH-1 in breast cancer cells and reveal its therapeutic potential for the treatment of breast cancers, notably for tumors resistant to treatments currently used in therapies. ChIP-seq examination of LRH-1 binding sites with specific chromatin marks in MCF7 breast cancer cells.