The activity of enhancers and promoters fine-tunes the transcriptional program of mammalian cells through the recruitment and interplay between cell type-specific and ubiquitous transcription factors. Despite their key role in modulating transcription, the identification of enhancers is challenged by their limited sequence conservation and highly variable distance from target genes. Although enhancers are characterised by the strong enrichment of mono-methylation at lysine 4 of histone H3, mirrored by low tri-methylation at the same residue, a comprehensive list of enhancers-associated histone post-translational modifications (PTMs) is still lacking. We undertook a proteomics investigation, based on chromatin immunoprecipitation combined with mass spectrometry (MS), to identify histone marks specifically associated to cis-regulatory elements in macrophages, focusing on enhancers. We also profiled their plasticity during the transcriptional activation induced by an inflammatory stimulus. The proteomic analysis suggested novel PTM associations, which were validated by analysis of ChIP- and RNA-seq data, whose intersection revealed the existence of novel sub-populations of enhancers marked by specific signatures: the dual mark H3K4me1/K36me2 labels transcription at enhancers, whereas H3K4me1/K36me3 and H3K4me1/K79me2 tag distinct intronic enhancers. While demonstrating that analyzing restricted genomic regions can disclose the combinatorial language of histone modifications, this study highlights the potential of MS-based proteomics in addressing fundamental questions in epigenetics. Overall design: Total RNA was extracted from 5x10^6 untreated RAW 264.7 cells using RNAeasy kit (Qiagen). Libraries were then prepared using TruSeq RNA sample preparation Kit (Illumina) after depleting ribosomal RNA
Chromatin proteomics reveals novel combinatorial histone modification signatures that mark distinct subpopulations of macrophage enhancers.
Specimen part, Cell line, Treatment, Subject
View SamplesUsing primary human bronchial epithelial cells collected at bronchoscopy, we have perturbed signaling pathways important in regulation of response to tobacco smoke exposure and cancer development: ATM, BCL2, GPX1, NOS2, IKBKB, and SIRT1
SIRT1 pathway dysregulation in the smoke-exposed airway epithelium and lung tumor tissue.
Specimen part
View SamplesFibroblasts synthesize the extracellular matrix of connective tissue and play an essential role in maintaining tissue integrity. We have previously shown that mouse skin connective tissue, the dermis, is comprised of functionally distinct fibroblast lineages. However, the extent of fibroblast heterogeneity in human skin is unknown. Here, using a combination of spatial transcriptional profiling of human and mouse dermis and single cell transcriptional profiling of human dermal fibroblasts, we show that there are at least four distinct fibroblast populations in adult human skin. We define markers permitting prospective isolation of these cells and show that although marker expression is rapidly lost in culture, different fibroblast subpopulations retain distinct functionality in terms of Wnt signalling, T cell communication and the ability to support human epidermal reconstitution in organotypic culture. Furthermore, while some fibroblast subpopulations are spatially segregated, others are not. These findings have profound implications for normal wound healing and diseases characterized by excessive fibrosis, and suggest that ex vivo expansion or in vivo ablation of specific fibroblast subpopulations may have therapeutic applications. Overall design: Spatial RNA sequencing of human papillary versus reticular dermis for 3 individuals, and single cell RNA sequencing of dermal fibroblasts for a single individual.
Spatial and Single-Cell Transcriptional Profiling Identifies Functionally Distinct Human Dermal Fibroblast Subpopulations.
Specimen part, Subject
View SamplesTreating unselected cancer patients with new drugs dilutes proof of efficacy when only a fraction of patients respond to therapy. We conducted a meta-analysis on eight primary breast cancer microarray datasets representing diverse breast cancer phenotypes. We present a high-throughput protocol which incorporates drug sensitivity signatures to guide preclinical testing for effective therapeutic agents. Specifically, we focus on drug classes currently undergoing early phase clinical testing. Our genomic and experimental results suggest that the majority of basal-like breast cancers should respond to inhibitors of the phosphatidylinositol-3-kinase pathway, and that a relatively low toxicity histone deacetylase inhibitor, valproic acid, may target aggressive breast cancers. For a subset of drugs, prediction of sensitivity associates with tumor recurrence, suggesting clinical relevance. Preclinical studies using both cell lines and patient tumors grown in 3-dimensional in vitro and orthotopic in vivo preclinical models provide an efficient and highly relevant assessment of drug sensitivity in tumor phenotypes, and validate our genomic analyses. Together, our results show that high-throughput transcriptional profiling can significantly impact drug selection for breast cancer patients. Pre-identification of patient response may not only improve therapeutic response rates, it can also assist in quickly identifying the optimal inclusion criteria for clinical trials. Our model facilitates personalized drug therapy for cancer patients and may be generalized for study of drug efficacy in other diseases.
A pharmacogenomic method for individualized prediction of drug sensitivity.
Specimen part
View SamplesExpression data from P2 mouse fibroblasts sorted for CD26, Sca1 and Dlk1. We have sorted mouse fibroblasts using the different lineages markers
Spatial and Single-Cell Transcriptional Profiling Identifies Functionally Distinct Human Dermal Fibroblast Subpopulations.
Specimen part
View SamplesThe genomic repertoire of enhancers and promoters that control the transcriptional output of terminally differentiated cells includes cell type-specific and housekeeping elements. Whether the constitutive activity of these two groups of cis-regulatory elements relies on entirely distinct or instead shared regulators is unknown. By dissecting the cis-regulatory repertoire of macrophages, we found that the ELF subfamily of ETS proteins selectively bound within 60 bp from the transcription start sites of highly active housekeeping genes. ELFs also bound constitutively active, but not poised macrophage-specific enhancers and promoters. The role of ELFs in promoting constitutive transcription is suggested by multiple evidences: ELF sites enabled transcriptional activation by endogenous and minimal synthetic promoters; ELF recruitment was stabilized by the transcriptional machinery, and ELF proteins mediated recruitment of transcriptional and chromatin regulators to core promoters. These data indicate that a distinct subfamily of ETS proteins imparts high transcriptional activity to a broad range of housekeeping and tissue-specific cis-regulatory elements, which is consistent with the role of an ETS family ancestor in core promoter regulation in a lower eukaryote. Overall design: Nascent RNA sequencing of primary bone marrow-derived macrophages (BMDM) This series contains a re-analysis of GSM1880858 from GSE73021. The file MacroTFs_171-genes.fpkm_tracking.gz contains the FPKM values for this sample.
High constitutive activity of a broad panel of housekeeping and tissue-specific <i>cis</i>-regulatory elements depends on a subset of ETS proteins.
Specimen part, Cell line, Treatment, Subject
View SamplesCytologically normal airway epithelial samples were collected during bronchoscopy of current and former smokers. Subjects enrolled in this study were either under suspicion of having lung cancer, had dysplasia in their airway, or were a healthy current, former or never smoker. We supplemented existing GEO series (GSE4115 and GSE7895) with the samples in this study to explore PI3K pathway activity in the these cohorts.
Airway PI3K pathway activation is an early and reversible event in lung cancer development.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Chromatin structure and gene expression programs of human embryonic and induced pluripotent stem cells.
Cell line
View SamplesKnowledge of both the global chromatin structure and the gene expression programs of human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells should provide a robust means to assess whether the genomes of these cells have similar pluripotent states. Recent studies have suggested that ES and iPS cells represent different pluripotent states with substantially different gene expression profiles. We describe here a comparison of global chromatin structure and gene expression data for a panel of human ES and iPS cells. Genome-wide maps of nucleosomes with histone H3K4me3 and H3K27me3 modifications indicate that there is little difference between ES and iPS cells with respect to these marks. Gene expression profiles confirm that the transcriptional programs of ES and iPS cells show very few consistent differences. Although some variation in chromatin structure and gene expression was observed in these cell lines, these variations did not serve to distinguish ES from iPS cells.
Chromatin structure and gene expression programs of human embryonic and induced pluripotent stem cells.
Cell line
View SamplesIn this study we obtained gene expression profiles of MCFS and parental MCF7 cell lines using Illumina microarrays
In-depth characterization of breast cancer tumor-promoting cell transcriptome by RNA sequencing and microarrays.
Specimen part, Cell line
View Samples