This study identified genomwide KCl inducible readthrough transcription. The project also includes a Cap-Seq experiment to identify transcriptional start sites, demonstrating that KCl does not activate downstream transcriptional start sites, but indeed does induce readthrough
Widespread Inducible Transcription Downstream of Human Genes.
No sample metadata fields
View SamplesWe used microarrays to detail the global program of gene expression during early hESC differentiation to mesendoderm using FBS, with and without RUNX1 depletion.
Transient RUNX1 Expression during Early Mesendodermal Differentiation of hESCs Promotes Epithelial to Mesenchymal Transition through TGFB2 Signaling.
Specimen part, Cell line
View SamplesThe onset and progression of breast cancer are linked to genetic and epigenetic changes that alter the normal programming of cells. Epigenetic modifications of DNA and histones contribute to chromatin structure that results in the activation or repression of gene expression. Several epigenetic pathways have been shown to be highly deregulated in cancer cells. Targeting specific histone modifications represents a viable strategy to prevent oncogenic transformation, tumor growth or metastasis. Methylation of histone H3 lysine 4 has been extensively studied and shown to mark genes for expression; however this residue can also be acetylated and the specific function of this alteration is less well known. To define the relative roles of histone H3 methylation (H3K4me3) and acetylation (H3K4ac) in breast cancer, we determined genomic regions enriched for both marks in normal-like (MCF10A), transformed (MCF7) and metastatic (MDA-MB-231) cells using a genome-wide ChIP-Seq approach. Our data revealed a genome-wide gain of H3K4ac associated with both early and late breast cancer cell phenotypes, while gain of H3K4me3 was predominantly associated with late stage cancer cells. Enrichment of H3K4ac was overrepresented at promoters of genes associated with cancer-related phenotypic traits, such as estrogen response and epithelial-to-mesenchymal transition pathways. Our findings highlight an important role for H3K4ac in predicting epigenetic changes associated with early stages of transformation. In addition, our data provide a valuable resource for understanding epigenetic signatures that correlate with known breast cancer-associated oncogenic pathways. Overall design: RNA-Seq of cell lines MCF10A, MCF7 and MDA-MB-231.
Histone H3 lysine 4 acetylation and methylation dynamics define breast cancer subtypes.
No sample metadata fields
View SamplesTranscription is a highly regulated process, and stress-induced changes in gene transcription have been shown to play a major role in responses and adaptation to stress. Numerous emerging genome-wide studies reveal prevalent transcription beyond known protein-coding gene loci, generating a variety of new classes of RNAs, most of unknown function. One such class, termed downstream of gene (DoG)-containing transcripts, was reported to result from transcriptional readthrough upon osmotic stress in human cell lines. However, how widespread the readthrough phenomenon is, and what its causes and consequences are, remain elusive. Here we present a systematic genome-wide mapping of transcriptional readthrough, using deep nuclear RNA-seq, comparing heat shock, osmotic and oxidative stress in NIH3T3 mouse fibroblast cells. We observe massive induction of transcriptional readthrough under all stress conditions, with significant, yet not complete overlap of readthrough-induced loci between different conditions. Importantly, our analyses suggest that stress-induced transcriptional readthrough is not a random failure process, but is rather differentially induced across different conditions. Additionally, analyzing public Pol-II occupancy data further supported our findings of stress-induced readthrough. We explore potential regulators and find a role for HSF1 in the induction of a subset of heat shock-induced readthrough transcripts. Furthermore, we examine genomic features of readthrough transcription, and observe a unique chromatin signature typical of DoG-producing regions, suggesting that readthrough transcription is associated with the maintenance of an open chromatin state. Overall design: RNA profiles of NIH3T3 (mouse embryonic fibroblasts) cells after three stress treatments and control were generated by deep sequencing, in two replicates using Illumina HiSeq 2000.
Comparative analysis reveals genomic features of stress-induced transcriptional readthrough.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genomic occupancy of Runx2 with global expression profiling identifies a novel dimension to control of osteoblastogenesis.
Specimen part
View SamplesOsteogenesis is a highly regulated developmental process and continues during the turnover and repair of mature bone. Runx2, the master regulator of osteoblastogenesis, directs a transcription program essential for bone formation through both genetic and epigenetic mechanisms. While individual Runx2 gene targets have been identified, further insights into the broad spectrum of Runx2 functions required for osteogenesis are needed. By performing genome-wide characterization of Runx2 binding at the three major stages of osteoblast differentiation: proliferation, matrix deposition and mineralization, we identified Runx2-dependent regulatory networks driving bone formation. Using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-Seq) over the course of these stages, we discovered close to 80,000 significantly enriched regions of Runx2 binding throughout the mouse genome. These binding events exhibited distinct patterns during osteogenesis, and were associated with proximal promoters as well as a large percentage of Runx2 occupancy in non-promoter regions: upstream, introns, exons, transcription termination site (TTS) regions, and intergenic regions. These peaks were partitioned into clusters that are associated with genes in complex biological processes that support bone formation. Using Affymetrix expression profiling of differentiating osteoblasts depleted of Runx2, we identified novel Runx2 targets including Ezh2, a critical epigenetic regulator; Crabp2, a retinoic acid signaling component; Adamts4 and Tnfrsf19, two remodelers of extracellular matrix. We demonstrated by luciferase assays that these novel biological targets are regulated by Runx2 occupancy at non-promoter regions. Our data establish that Runx2 interactions with chromatin across the genome reveal novel genes, pathways and transcriptional mechanisms that contribute to the regulation of osteoblastogenesis.
Genomic occupancy of Runx2 with global expression profiling identifies a novel dimension to control of osteoblastogenesis.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identifying Nuclear Matrix-Attached DNA Across the Genome.
Specimen part, Cell line
View SamplesWe used microarrays to detail the global programme of gene expression during early hESC differentiation to Mesendoderm using FBS.
Lineage-Specific Early Differentiation of Human Embryonic Stem Cells Requires a G2 Cell Cycle Pause.
Sex, Cell line, Time
View SamplesThis study was performed to identify gene expression differences in not otherwise specified soft tissue sarcomas (NOS, malignant fibrous histiocytomas) and correlate them to histological findings and the clinical course. RNA was isolated and differential gene expression was analysed by the microarray technique.
Malignant fibrous histiocytoma--pleomorphic sarcoma, NOS gene expression, histology, and clinical course. A pilot study.
Sex
View SamplesExperimental approaches to define the relationship between gene expression and nuclear matrix attachment regions (MARs) have given contrasting and method-specific results. We have developed a next generation sequencing strategy to identify MARs across the human genome (MAR-Seq). The method is based on crosslinking chromatin to its nuclear matrix attachment sites to minimize changes during biochemical processing. We used this method to compare nuclear matrix organization in MCF-10A mammary epithelial-like cells and MDA-MB-231 breast cancer cells and evaluated the results in the context of global gene expression (array analysis) and positional enrichment of gene-regulatory histone modifications (ChIP-Seq). In the normal-like cells, nuclear matrixattached DNA was enriched in expressed genes, while in the breast cancer cells, it was enriched in non-expressed genes. In both cell lines, the chromatin modifications that mark transcriptional activation or repression were appropriately associated with gene expression. Using this new MAR-Seq approach, we provide the first genome-wide characterization of nuclear matrix attachment in mammalian cells and reveal that the nuclear matrixassociated genome is highly cell-context dependent.
Identifying Nuclear Matrix-Attached DNA Across the Genome.
Specimen part, Cell line
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