scholarly journals Identification of a primitive intestinal transcription factor network shared between oesophageal adenocarcinoma and its pre-cancerous precursor state

2018 ◽  
Author(s):  
Connor Rogerson ◽  
Edward Britton ◽  
Sarah Withey ◽  
Neil Hanley ◽  
Yeng S. Ang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Regulatory Networks ◽  
Oesophageal Adenocarcinoma ◽  
Molecular Evidence ◽  
Open Chromatin ◽  
Chromatin Signature ◽  
Precursor State ◽  
Transcription Factor Network ◽  
A Genome ◽  
Chromatin Profiling

AbstractOesophageal adenocarcinoma (OAC) is one of the most frequent causes of cancer deaths and yet compared to other common cancers, we know relatively little about the molecular composition of this tumour type. To further our understanding of this cancer we have used open chromatin profiling to decipher the transcriptional regulatory networks that are operational in OAC. We have uncovered a transcription factor network that is usually found in primitive intestinal cells during embryonic development, centred on HNF4A and GATA6. These transcription factors work together to control the OAC transcriptome. Importantly, we show that this network is activated in Barrett’s oesophagus, the putative precursor state to OAC thereby providing novel molecular evidence in support of stepwise malignant transition. Furthermore, we show that HNF4A alone, is sufficient to drive chromatin opening and activation of a Barrett’s-like chromatin signature when expressed in normal human epithelial cells. Collectively, these data provide a new way to categorise OAC at a genome scale and implicate HNF4A activation as a potential pivotal event in regulating its malignant transition from healthy cells.

scholarly journals Comparative analysis reveals genomic features of stress-induced transcriptional readthrough

2017 ◽  
Vol 114 (40) ◽  
pp. E8362-E8371 ◽  
Author(s):  
Anna Vilborg ◽  
Niv Sabath ◽  
Yuval Wiesel ◽  
Jenny Nathans ◽  
Flonia Levy-Adam ◽  
...  
Keyword(s):  
Heat Shock ◽  
Osmotic Stress ◽  
Stress Responses ◽  
Failure Process ◽  
Mouse Fibroblast ◽  
Open Chromatin ◽  
Chromatin Signature ◽  
Genomic Features ◽  
Genome Wide ◽  
A Genome

Transcription is a highly regulated process, and stress-induced changes in gene transcription have been shown to play a major role in stress responses and adaptation. Genome-wide studies reveal prevalent transcription beyond known protein-coding gene loci, generating a variety of RNA classes, most of unknown function. One such class, termed downstream of gene-containing transcripts (DoGs), was reported to result from transcriptional readthrough upon osmotic stress in human cells. However, how widespread the readthrough phenomenon is, and what its causes and consequences are, remain elusive. Here we present a genome-wide mapping of transcriptional readthrough, using nuclear RNA-Seq, comparing heat shock, osmotic stress, and oxidative stress in NIH 3T3 mouse fibroblast cells. We observe massive induction of transcriptional readthrough, both in levels and length, 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. We explore potential regulators and find a role for HSF1 in the induction of a subset of heat shock-induced readthrough transcripts. Analysis of public datasets detected increases in polymerase II occupancy in DoG regions after heat shock, supporting our findings. Interestingly, DoGs tend to be produced in the vicinity of neighboring genes, leading to a marked increase in their antisense-generating potential. Finally, 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.

scholarly journals Identification of a primitive intestinal transcription factor network shared between esophageal adenocarcinoma and its precancerous precursor state

2019 ◽  
Vol 29 (5) ◽  
pp. 723-736 ◽  
Author(s):  
Connor Rogerson ◽  
Edward Britton ◽  
Sarah Withey ◽  
Neil Hanley ◽  
Yeng S. Ang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Esophageal Adenocarcinoma ◽  
Precursor State ◽  
Transcription Factor Network

scholarly journals Open chromatin profiling identifies AP1 as a transcriptional regulator in oesophageal adenocarcinoma

PLoS Genetics ◽  
2017 ◽  
Vol 13 (8) ◽  
pp. e1006879 ◽  
Author(s):  
Edward Britton ◽  
Connor Rogerson ◽  
Shaveta Mehta ◽  
Yaoyong Li ◽  
Xiaodun Li ◽  
...  
Keyword(s):  
Transcriptional Regulator ◽  
Oesophageal Adenocarcinoma ◽  
Open Chromatin ◽  
Chromatin Profiling

scholarly journals Scrt1, a transcriptional regulator of β-cell proliferation identified by differential chromatin accessibility during islet maturation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan Sobel ◽  
Claudiane Guay ◽  
Ofer Elhanani ◽  
Adriana Rodriguez-Trejo ◽  
Lisa Stoll ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Transcription Factor ◽  
Cell Mass ◽  
Transcriptional Repressor ◽  
Open Chromatin ◽  
Β Cells ◽  
Β Cell ◽  
Functional Maturation ◽  
A Genome

AbstractGlucose-induced insulin secretion, a hallmark of mature β-cells, is achieved after birth and is preceded by a phase of intense proliferation. These events occurring in the neonatal period are decisive for establishing an appropriate functional β-cell mass that provides the required insulin throughout life. However, key regulators of gene expression involved in functional maturation of β-cells remain to be elucidated. Here, we addressed this issue by mapping open chromatin regions in newborn versus adult rat islets using the ATAC-seq assay. We obtained a genome-wide picture of chromatin accessible sites (~ 100,000) among which 20% were differentially accessible during maturation. An enrichment analysis of transcription factor binding sites identified a group of transcription factors that could explain these changes. Among them, Scrt1 was found to act as a transcriptional repressor and to control β-cell proliferation. Interestingly, Scrt1 expression was controlled by the transcriptional repressor RE-1 silencing transcription factor (REST) and was increased in an in vitro reprogramming system of pancreatic exocrine cells to β-like cells. Overall, this study led to the identification of several known and unforeseen key transcriptional events occurring during β-cell maturation. These findings will help defining new strategies to induce the functional maturation of surrogate insulin-producing cells.

scholarly journals Multi-omic regulatory networks capture downstream effects of kinase inhibition in Mycobacterium tuberculosis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Albert T. Young ◽  
Xavier Carette ◽  
Michaela Helmel ◽  
Hanno Steen ◽  
Robert N. Husson ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Mycobacterium Tuberculosis ◽  
Regulatory Network ◽  
Regulatory Networks ◽  
Protein Interaction Data ◽  
Kinase Inhibition ◽  
Protein Protein Interaction ◽  
Downstream Effects ◽  
Regulate Cell Growth ◽  
Regulatory Effects

AbstractThe ability of Mycobacterium tuberculosis (Mtb) to adapt to diverse stresses in its host environment is crucial for pathogenesis. Two essential Mtb serine/threonine protein kinases, PknA and PknB, regulate cell growth in response to environmental stimuli, but little is known about their downstream effects. By combining RNA-Seq data, following treatment with either an inhibitor of both PknA and PknB or an inactive control, with publicly available ChIP-Seq and protein–protein interaction data for transcription factors, we show that the Mtb transcription factor (TF) regulatory network propagates the effects of kinase inhibition and leads to widespread changes in regulatory programs involved in cell wall integrity, stress response, and energy production, among others. We also observe that changes in TF regulatory activity correlate with kinase-specific phosphorylation of those TFs. In addition to characterizing the downstream regulatory effects of PknA/PknB inhibition, this demonstrates the need for regulatory network approaches that can incorporate signal-driven transcription factor modifications.

scholarly journals High-throughput single-cell chromatin accessibility CRISPR screens enable unbiased identification of regulatory networks in cancer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sarah E. Pierce ◽  
Jeffrey M. Granja ◽  
William J. Greenleaf
Keyword(s):  
Transcription Factor ◽  
Single Cell ◽  
Cancer Cells ◽  
High Throughput ◽  
Regulatory Networks ◽  
Temporal Dynamics ◽  
Chromatin Accessibility ◽  
Regulatory Regions ◽  
Factor Binding ◽  
Genome Wide

AbstractChromatin accessibility profiling can identify putative regulatory regions genome wide; however, pooled single-cell methods for assessing the effects of regulatory perturbations on accessibility are limited. Here, we report a modified droplet-based single-cell ATAC-seq protocol for perturbing and evaluating dynamic single-cell epigenetic states. This method (Spear-ATAC) enables simultaneous read-out of chromatin accessibility profiles and integrated sgRNA spacer sequences from thousands of individual cells at once. Spear-ATAC profiling of 104,592 cells representing 414 sgRNA knock-down populations reveals the temporal dynamics of epigenetic responses to regulatory perturbations in cancer cells and the associations between transcription factor binding profiles.

scholarly journals Cell-type-specific profiling of loaded miRNAs from Caenorhabditis elegans reveals spatial and temporal flexibility in Argonaute loading

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christopher A. Brosnan ◽  
Alexander J. Palmer ◽  
Steven Zuryn
Keyword(s):  
Caenorhabditis Elegans ◽  
Regulatory Networks ◽  
Regulatory Mechanisms ◽  
Cell Type ◽  
A Genome ◽  
Temporal Flexibility ◽  
Small Regulatory Rnas ◽  
Cell Type Specific ◽  
Single Cell Type ◽  
Regulated Gene Expression

AbstractMulticellularity has coincided with the evolution of microRNAs (miRNAs), small regulatory RNAs that are integrated into cellular differentiation and homeostatic gene-regulatory networks. However, the regulatory mechanisms underpinning miRNA activity have remained largely obscured because of the precise, and thus difficult to access, cellular contexts under which they operate. To resolve these, we have generated a genome-wide map of active miRNAs in Caenorhabditis elegans by revealing cell-type-specific patterns of miRNAs loaded into Argonaute (AGO) silencing complexes. Epitope-labelled AGO proteins were selectively expressed and immunoprecipitated from three distinct tissue types and associated miRNAs sequenced. In addition to providing information on biological function, we define adaptable miRNA:AGO interactions with single-cell-type and AGO-specific resolution. We demonstrate spatial and temporal dynamicism, flexibility of miRNA loading, and suggest miRNA regulatory mechanisms via AGO selectivity in different tissues and during ageing. Additionally, we resolve widespread changes in AGO-regulated gene expression by analysing translatomes specifically in neurons.

scholarly journals Subtype-associated epigenomic landscape and 3D genome structure in bladder cancer

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Tejaswi Iyyanki ◽  
Baozhen Zhang ◽  
Qixuan Wang ◽  
Ye Hou ◽  
Qiushi Jin ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Transcription Factor ◽  
Cancer Cell ◽  
Genome Structure ◽  
Transcription Factor Binding ◽  
Specific Gene ◽  
Open Chromatin ◽  
Factor Binding ◽  
3D Genome ◽  
Genome Wide

Abstract Muscle-invasive bladder cancers are characterized by their distinct expression of luminal and basal genes, which could be used to predict key clinical features such as disease progression and overall survival. Transcriptionally, FOXA1, GATA3, and PPARG are shown to be essential for luminal subtype-specific gene regulation and subtype switching, while TP63, STAT3, and TFAP2 family members are critical for regulation of basal subtype-specific genes. Despite these advances, the underlying epigenetic mechanisms and 3D chromatin architecture responsible for subtype-specific regulation in bladder cancer remain unknown. Result We determine the genome-wide transcriptome, enhancer landscape, and transcription factor binding profiles of FOXA1 and GATA3 in luminal and basal subtypes of bladder cancer. Furthermore, we report the first-ever mapping of genome-wide chromatin interactions by Hi-C in both bladder cancer cell lines and primary patient tumors. We show that subtype-specific transcription is accompanied by specific open chromatin and epigenomic marks, at least partially driven by distinct transcription factor binding at distal enhancers of luminal and basal bladder cancers. Finally, we identify a novel clinically relevant transcription factor, Neuronal PAS Domain Protein 2 (NPAS2), in luminal bladder cancers that regulates other subtype-specific genes and influences cancer cell proliferation and migration. Conclusion In summary, our work identifies unique epigenomic signatures and 3D genome structures in luminal and basal urinary bladder cancers and suggests a novel link between the circadian transcription factor NPAS2 and a clinical bladder cancer subtype.

scholarly journals Glucocorticoid receptor wields chromatin interactions to tune transcription for cytoskeleton stabilization in podocytes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Hong Wang ◽  
Aiping Duan ◽  
Jing Zhang ◽  
Qi Wang ◽  
Yuexian Xing ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Glucocorticoid Receptor ◽  
Protective Effect ◽  
Histone Modification ◽  
Regulatory Networks ◽  
Target Gene ◽  
Regulatory Elements ◽  
Chromatin Interactions ◽  
Super Enhancer

AbstractElucidating transcription mediated by the glucocorticoid receptor (GR) is crucial for understanding the role of glucocorticoids (GCs) in the treatment of diseases. Podocyte is a useful model for studying GR regulation because GCs are the primary medication for podocytopathy. In this study, we integrated data from transcriptome, transcription factor binding, histone modification, and genome topology. Our data reveals that the GR binds and activates selective regulatory elements in podocyte. The 3D interactome captured by HiChIP facilitates the identification of remote targets of GR. We found that GR in podocyte is enriched at transcriptional interaction hubs and super-enhancers. We further demonstrate that the target gene of the top GR-associated super-enhancer is indispensable to the effective functioning of GC in podocyte. Our findings provided insights into the mechanisms underlying the protective effect of GCs on podocyte, and demonstrate the importance of considering transcriptional interactions in order to fine-map regulatory networks of GR.

scholarly journals EPEN-30. C11ORF95-RELA FUSION PROTEIN ENGAGES NOVEL GENOMIC LOCI TO DRIVE MURINE EPENDYMOMA GROWTH

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii314-iii314
Author(s):  
Amir Arabzade ◽  
Yanhua Zhao ◽  
Srinidhi Varadharajan ◽  
Hsiao-Chi Chen ◽  
Austin Stuckert ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Binding Sites ◽  
Molecular Targets ◽  
Lead Target ◽  
Open Chromatin ◽  
Rna Seq ◽  
In Utero Electroporation ◽  
Pathway Activation ◽  
Mouse Cells ◽  
Shed Light

Abstract RATIONALE Over 70% of supratentorial (ST) ependymoma are characterized by an oncogenic fusion between C11ORF95 and RELA. C11ORF95-RELA fusion is frequently the sole genetic driver detected in ST ependymoma, thus ranking this genomic event as a lead target for therapeutic investigation. RELA is a transcription factor (TF) central to mediating NF-kB pathway activation in processes such as inflammation, cellular metabolism, and chemotaxis. HYPOTHESIS: We posited that C11ORF95-RELA acts as an oncogenic TF that aberrantly shapes the tumor epigenome to drive aberrant transcription. Approach: To this end we developed an in utero electroporation (IUE) mouse model of ependymoma to express C11ORF95-RELA during embryonic development. Our IUE approach allowed us to develop C11ORF95-RELA driven tumor models and cell lines. We comprehensively characterized the epigenome and transcriptome of C11ORF95-RELA fusion driven mouse cells by H3K27ac ChIP-seq, ATAC-seq, and RNA-seq. RESULTS This data revealed that: 1) C11ORF95-RELA directly engages ‘open’ chromatin and is enriched at regions with known RELA TF binding sites as well as novel genomic loci/motifs, 2) C11ORF95-RELA preferentially binds to both H3K27ac (active) enhancers and promoters, and 3) Bound C11ORF95-RELA promoter loci are associated with increased transcription of genes shared with human ependymoma. CONCLUSION Our findings shed light on the transcriptional mechanisms of C11ORF95-RELA, and reveal downstream targets that may represent cancer dependency genes and molecular targets.

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