scholarly journals Fra-1 regulates its target genes via binding to remote enhancers without exerting major control on chromatin architecture in triple negative breast cancers

2021 ◽  
Author(s):  
Fabienne Bejjani ◽  
Claire Tolza ◽  
Mathias Boulanger ◽  
Damien Downes ◽  
Raphaël Romero ◽  
...  
Keyword(s):  
Target Gene ◽  
Target Genes ◽  
Triple Negative ◽  
Regulatory Elements ◽  
Gene Promoters ◽  
Breast Cancers ◽  
Chromatin Architecture ◽  
Family Protein ◽  
Wide Range ◽  
Motif Recognition

Abstract The ubiquitous family of dimeric transcription factors AP-1 is made up of Fos and Jun family proteins. It has long been thought to operate principally at gene promoters and how it controls transcription is still ill-understood. The Fos family protein Fra-1 is overexpressed in triple negative breast cancers (TNBCs) where it contributes to tumor aggressiveness. To address its transcriptional actions in TNBCs, we combined transcriptomics, ChIP-seqs, machine learning and NG Capture-C. Additionally, we studied its Fos family kin Fra-2 also expressed in TNBCs, albeit much less. Consistently with their pleiotropic effects, Fra-1 and Fra-2 up- and downregulate individually, together or redundantly many genes associated with a wide range of biological processes. Target gene regulation is principally due to binding of Fra-1 and Fra-2 at regulatory elements located distantly from cognate promoters where Fra-1 modulates the recruitment of the transcriptional co-regulator p300/CBP and where differences in AP-1 variant motif recognition can underlie preferential Fra-1- or Fra-2 bindings. Our work also shows no major role for Fra-1 in chromatin architecture control at target gene loci, but suggests collaboration between Fra-1-bound and -unbound enhancers within chromatin hubs sometimes including promoters for other Fra-1-regulated genes. Our work impacts our view of AP-1.

scholarly journals EnhancerAtlas 2.0: an updated resource with enhancer annotation in 586 tissue/cell types across nine species

2019 ◽  
Author(s):  
Tianshun Gao ◽  
Jiang Qian
Keyword(s):  
Large Scale ◽  
Target Gene ◽  
Target Genes ◽  
Cell Types ◽  
Regulatory Elements ◽  
Tissue Cell ◽  
Normal Tissues ◽  
Genome Wide ◽  
Wide Range ◽  
User Friendly

Abstract Enhancers are distal cis-regulatory elements that activate the transcription of their target genes. They regulate a wide range of important biological functions and processes, including embryogenesis, development, and homeostasis. As more and more large-scale technologies were developed for enhancer identification, a comprehensive database is highly desirable for enhancer annotation based on various genome-wide profiling datasets across different species. Here, we present an updated database EnhancerAtlas 2.0 (http://www.enhanceratlas.org/indexv2.php), covering 586 tissue/cell types that include a large number of normal tissues, cancer cell lines, and cells at different development stages across nine species. Overall, the database contains 13 494 603 enhancers, which were obtained from 16 055 datasets using 12 high-throughput experiment methods (e.g. H3K4me1/H3K27ac, DNase-seq/ATAC-seq, P300, POLR2A, CAGE, ChIA-PET, GRO-seq, STARR-seq and MPRA). The updated version is a huge expansion of the first version, which only contains the enhancers in human cells. In addition, we predicted enhancer–target gene relationships in human, mouse and fly. Finally, the users can search enhancers and enhancer–target gene relationships through five user-friendly, interactive modules. We believe the new annotation of enhancers in EnhancerAtlas 2.0 will facilitate users to perform useful functional analysis of enhancers in various genomes.

scholarly journals EP300 and SIRT1/6 Co-Regulate Lapatinib Sensitivity Via Modulating FOXO3-Acetylation and Activity in Breast Cancer

Cancers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1067 ◽  
Author(s):  
Zimam Mahmud ◽  
Ana R. Gomes ◽  
Hee Jin Lee ◽  
Sathid Aimjongjun ◽  
Yannasittha Jiramongkol ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Target Gene ◽  
Target Genes ◽  
Ectopic Expression ◽  
Sirtuin 1 ◽  
Fine Tuning ◽  
Gene Promoters ◽  
Breast Cancers ◽  
Her2 Positive ◽  
Cancer Subtypes

Forkhead Box O3 (FOXO3) is a tumor suppressor whose activity is fine-tuned by post-translational modifications (PTMs). In this study, using the BT474 breast cancer cells and a recently established lapatinib resistant (BT474-LapR) cell line, we observed that higher FOXO3 and acetylated (Ac)-FOXO3 levels correlate with lapatinib sensitivity. Subsequent ectopic expression of EP300 led to an increase in acetylated-FOXO3 in sensitive but not in resistant cells. Drug sensitivity assays revealed that sensitive BT474 cells show increased lapatinib cytotoxicity upon over-expression of wild-type but not acetylation-deficient EP300. Moreover, FOXO3 recruitment to target gene promoters is associated with target gene expression and drug response in sensitive cells and the inability of FOXO3 to bind its target genes correlates with lapatinib-resistance in BT474-LapR cells. In addition, using SIRT1/6 specific siRNAs and chemical inhibitor, we also found that sirtuin 1 and -6 (SIRT1 and -6) play a part in fine-tuning FOXO3 acetylation and lapatinib sensitivity. Consistent with this, immunohistochemistry results from different breast cancer subtypes showed that high SIRT6/1 levels are associated with constitutive high FOXO3 expression which is related to FOXO3 deregulation/inactivation and poor prognosis in breast cancer patient samples. Collectively, our results suggest the involvement of FOXO3 acetylation in regulating lapatinib sensitivity of HER2-positive breast cancers.

scholarly journals Global reorganisation of cis-regulatory units upon lineage commitment of human embryonic stem cells

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Paula Freire-Pritchett ◽  
Stefan Schoenfelder ◽  
Csilla Várnai ◽  
Steven W Wingett ◽  
Jonathan Cairns ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Target Gene ◽  
Target Genes ◽  
Embryonic Stem ◽  
Regulatory Elements ◽  
Dna Looping ◽  
Lineage Commitment ◽  
Gene Promoters ◽  
Putative Target ◽  
Target Promoters

Long-range cis-regulatory elements such as enhancers coordinate cell-specific transcriptional programmes by engaging in DNA looping interactions with target promoters. Deciphering the interplay between the promoter connectivity and activity of cis-regulatory elements during lineage commitment is crucial for understanding developmental transcriptional control. Here, we use Promoter Capture Hi-C to generate a high-resolution atlas of chromosomal interactions involving ~22,000 gene promoters in human pluripotent and lineage-committed cells, identifying putative target genes for known and predicted enhancer elements. We reveal extensive dynamics of cis-regulatory contacts upon lineage commitment, including the acquisition and loss of promoter interactions. This spatial rewiring occurs preferentially with predicted changes in the activity of cis-regulatory elements and is associated with changes in target gene expression. Our results provide a global and integrated view of promoter interactome dynamics during lineage commitment of human pluripotent cells.

scholarly journals TrkA Interacts with and Phosphorylates STAT3 to Enhance Gene Transcription and Promote Breast Cancer Stem Cells in Triple-Negative and HER2-Enriched Breast Cancers

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2340
Author(s):  
Angelina T. Regua ◽  
Noah R. Aguayo ◽  
Sara Abu Jalboush ◽  
Daniel L. Doheny ◽  
Sara G. Manore ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Gene Transcription ◽  
Target Genes ◽  
Triple Negative ◽  
Breast Cancer Stem Cells ◽  
Breast Cancers ◽  
Co Activation ◽  
Stat3 Phosphorylation

JAK2–STAT3 and TrkA signaling pathways have been separately implicated in aggressive breast cancers; however, whether they are co-activated or undergo functional interaction has not been thoroughly investigated. Herein we report, for the first time that STAT3 and TrkA are significantly co-overexpressed and co-activated in triple-negative breast cancer (TNBC) and HER2-enriched breast cancer, as shown by immunohistochemical staining and data mining. Through immunofluorescence staining–confocal microscopy and immunoprecipitation–Western blotting, we found that TrkA and STAT3 co-localize and physically interact in the cytoplasm, and the interaction is dependent on STAT3-Y705 phosphorylation. TrkA–STAT3 interaction leads to STAT3 phosphorylation at Y705 by TrkA in breast cancer cells and cell-free kinase assays, indicating that STAT3 is a novel substrate of TrkA. β-NGF-mediated TrkA activation induces TrkA–STAT3 interaction, STAT3 nuclear transport and transcriptional activity, and the expression of STAT3 target genes, SOX2 and MYC. The co-activation of both pathways promotes breast cancer stem cells. Finally, we found that TNBC and HER2-enriched breast cancer with JAK2–STAT3 and TrkA co-activation are positively associated with poor overall metastasis-free and organ-specific metastasis-free survival. Collectively, our study uncovered that TrkA is a novel activating kinase of STAT3, and their co-activation enhances gene transcription and promotes breast cancer stem cells in TNBC and HER2-enriched breast cancer.

Androgen receptor: acting in the three-dimensional chromatin landscape of prostate cancer cells

2011 ◽  
Vol 5 (1) ◽  
Author(s):  
Harri Makkonen ◽  
Jorma J. Palvimo
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Binding Sites ◽  
Target Genes ◽  
Three Dimensional ◽  
Regulatory Elements ◽  
Gene Promoters ◽  
Loop Formation ◽  
Prostate Cancer Cells

AbstractAndrogen receptor (AR) acts as a hormone-controlled transcription factor that conveys the messages of both natural and synthetic androgens to the level of genes and gene programs. Defective AR signaling leads to a wide array of androgen insensitivity disorders, and deregulated AR function, in particular overexpression of AR, is involved in the growth and progression of prostate cancer. Classic models of AR action view AR-binding sites as upstream regulatory elements in gene promoters or their proximity. However, recent wider genomic screens indicate that AR target genes are commonly activated through very distal chromatin-binding sites. This highlights the importance of long-range chromatin regulation of transcription by the AR, shifting the focus from the linear gene models to three-dimensional models of AR target genes and gene programs. The capability of AR to regulate promoters from long distances in the chromatin is particularly important when evaluating the role of AR in the regulation of genes in malignant prostate cells that frequently show striking genomic aberrations, especially gene fusions. Therefore, in addition to the mechanisms of DNA loop formation between the enhancer bound ARs and the transcription apparatus at the target core promoter, the mechanisms insulating distally bound ARs from promiscuously making contacts and activating other than their normal target gene promoters are critical for proper physiological regulation and thus currently under intense investigation. This review discusses the current knowledge about the AR action in the context of gene aberrations and the three-dimensional chromatin landscape of prostate cancer cells.

scholarly journals Target Gene Specificity of E2F and Pocket Protein Family Members in Living Cells

2000 ◽  
Vol 20 (16) ◽  
pp. 5797-5807 ◽  
Author(s):  
Julie Wells ◽  
Kathryn E. Boyd ◽  
Christopher J. Fry ◽  
Stephanie M. Bartley ◽  
Peggy J. Farnham
Keyword(s):  
Cell Cycle ◽  
Target Gene ◽  
Target Genes ◽  
Protein Complexes ◽  
Current Model ◽  
Family Members ◽  
Living Cells ◽  
Gene Promoters ◽  
Pocket Protein ◽  
Protein Dna Interactions

ABSTRACT E2F-mediated transcription is thought to involve binding of an E2F-pocket protein complex to promoters in the G0 phase of the cell cycle and release of the pocket protein in late G1, followed by release of E2F in S phase. We have tested this model by monitoring protein-DNA interactions in living cells using a formaldehyde cross-linking and immunoprecipitation assay. We find that E2F target genes are bound by distinct E2F-pocket protein complexes which change as cells progress through the cell cycle. We also find that certain E2F target gene promoters are bound by pocket proteins when such promoters are transcriptionally active. Our data indicate that the current model applies only to certain E2F target genes and suggest that Rb family members may regulate transcription in both G0 and S phases. Finally, we find that a given promoter can be bound by one of several different E2F-pocket protein complexes at a given time in the cell cycle, suggesting that cell cycle-regulated transcription is a stochastic, not a predetermined, process.

scholarly journals Regulation of Poly(ADP-ribose) Polymerase-1-dependent Gene Expression through Promoter-directed Recruitment of a Nuclear NAD+ Synthase

2012 ◽  
Vol 287 (15) ◽  
pp. 12405-12416 ◽  
Author(s):  
Tong Zhang ◽  
Jhoanna G. Berrocal ◽  
Jie Yao ◽  
Michelle E. DuMond ◽  
Raga Krishnakumar ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Target Gene ◽  
Target Genes ◽  
Enzymatic Activities ◽  
Gene Promoters ◽  
Protein Coding ◽  
Photon Excitation ◽  
Gene Sets ◽  
Cellular Compartments ◽  
Parp 1

NMNAT-1 and PARP-1, two key enzymes in the NAD+ metabolic pathway, localize to the nucleus where integration of their enzymatic activities has the potential to control a variety of nuclear processes. Using a variety of biochemical, molecular, cell-based, and genomic assays, we show that NMNAT-1 and PARP-1 physically and functionally interact at target gene promoters in MCF-7 cells. Specifically, we show that PARP-1 recruits NMNAT-1 to promoters where it produces NAD+ to support PARP-1 catalytic activity, but also enhances the enzymatic activity of PARP-1 independently of NAD+ production. Furthermore, using two-photon excitation microscopy, we show that NMNAT-1 catalyzes the production of NAD+ in a nuclear pool that may be distinct from other cellular compartments. In expression microarray experiments, depletion of NMNAT-1 or PARP-1 alters the expression of about 200 protein-coding genes each, with about 10% overlap between the two gene sets. NMNAT-1 enzymatic activity is required for PARP-1-dependent poly(ADP-ribosyl)ation at the promoters of commonly regulated target genes, as well as the expression of those target genes. Collectively, our studies link the enzymatic activities of NMNAT-1 and PARP-1 to the regulation of a set of common target genes through functional interactions at target gene promoters.

scholarly journals Epigenetic Regulation of Immunotherapy Response in Triple-Negative Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4139
Author(s):  
Pere Llinàs-Arias ◽  
Sandra Íñiguez-Muñoz ◽  
Kelly McCann ◽  
Leonie Voorwerk ◽  
Javier I. J. Orozco ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Immune Escape ◽  
Checkpoint Inhibitors ◽  
Early Stage ◽  
Regulatory Elements ◽  
Her2 Overexpression ◽  
Breast Cancers ◽  
Cancer Subtypes

Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptor and progesterone receptor and human epidermal growth factor receptor 2 (HER2) overexpression. This malignancy, representing 15–20% of breast cancers, is a clinical challenge due to the lack of targeted treatments, higher intrinsic aggressiveness, and worse outcomes than other breast cancer subtypes. Immune checkpoint inhibitors have shown promising efficacy for early-stage and advanced TNBC, but this seems limited to a subgroup of patients. Understanding the underlying mechanisms that determine immunotherapy efficiency is essential to identifying which TNBC patients will respond to immunotherapy-based treatments and help to develop new therapeutic strategies. Emerging evidence supports that epigenetic alterations, including aberrant chromatin architecture conformation and the modulation of gene regulatory elements, are critical mechanisms for immune escape. These alterations are particularly interesting since they can be reverted through the inhibition of epigenetic regulators. For that reason, several recent studies suggest that the combination of epigenetic drugs and immunotherapeutic agents can boost anticancer immune responses. In this review, we focused on the contribution of epigenetics to the crosstalk between immune and cancer cells, its relevance on immunotherapy response in TNBC, and the potential benefits of combined treatments.

scholarly journals HCR-FlowFISH: A flexible CRISPR screening method to identify cis-regulatory elements and their target genes

2020 ◽  
Author(s):  
SK Reilly ◽  
SJ Gosai ◽  
A Gutierrez ◽  
JC Ulirsch ◽  
M Kanai ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Screening Method ◽  
Cell Types ◽  
Regulatory Elements ◽  
Hybridization Chain Reaction ◽  
Genome Wide ◽  
Wide Range ◽  
Causal Variants ◽  
Endogenous Loci

AbstractCRISPR screens for cis-regulatory elements (CREs) have shown unprecedented power to endogenously characterize the non-coding genome. To characterize CREs we developed HCR-FlowFISH (Hybridization Chain Reaction Fluorescent In-Situ Hybridization coupled with Flow Cytometry), which directly quantifies native transcripts within their endogenous loci following CRISPR perturbations of regulatory elements, eliminating the need for restrictive phenotypic assays such as growth or transcript-tagging. HCR-FlowFISH accurately quantifies gene expression across a wide range of transcript levels and cell types. We also developed CASA (CRISPR Activity Screen Analysis), a hierarchical Bayesian model to identify and quantify CRE activity. Using >270,000 perturbations, we identified CREs for GATA1, HDAC6, ERP29, LMO2, MEF2C, CD164, NMU, FEN1 and the FADS gene cluster. Our methods detect subtle gene expression changes and identify CREs regulating multiple genes, sometimes at different magnitudes and directions. We demonstrate the power of HCR-FlowFISH to parse genome-wide association signals by nominating causal variants and target genes.

scholarly journals Identification of key genes and associated pathways in neuroendocrine tumors through bioinformatics analysis and predictions of small drug molecules

2020 ◽  
Author(s):  
Praveenkumar Devarbhavi ◽  
Basavaraj Vastrad ◽  
Anandkumar Tengli ◽  
Chanabasayya Vastrad ◽  
Iranna Kotturshetti
Keyword(s):  
Drug Target ◽  
Target Gene ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Regulatory Elements ◽  
Future Research ◽  
High Morbidity ◽  
Hub Genes ◽  
Go Enrichment ◽  
Significant Difference

AbstractNeuroendocrine tumor (NET) is one of malignant cancer and is identified with high morbidity and mortality rates around the world. With indigent clinical outcomes, potential biomarkers for diagnosis, prognosis and drug target are crucial to explore. The aim of this study is to examine the gene expression module of NET and to identify potential diagnostic and prognostic biomarkers as well as to find out new drug target. The differentially expressed genes (DEGs) identified from GSE65286 dataset was used for pathway enrichment analyses and gene ontology (GO) enrichment analyses and protein - protein interaction (PPI) analysis and module analysis. Moreover, miRNAs and transcription factors (TFs) that regulated the up and down regulated genes were predicted. Furthermore, validation of hub genes was performed. Finally, molecular docking studies were performed. DEGs were identified, including 453 down regulated and 459 up regulated genes. Pathway and GO enrichment analysis revealed that DEGs were enriched in sucrose degradation, creatine biosynthesis, anion transport and modulation of chemical synaptic transmission. Important hub genes and target genes were identified through PPI network, modules, target gene - miRNA network and target gene - TF network. Finally, survival analyses, receiver operating characteristic (ROC) curve and RT-PCR validated the significant difference of ATP1A1, LGALS3, LDHA, SYK, VDR, OBSL1, KRT40, WWOX, NINL and PPP2R2B between metastatic NET and normal controls. In conclusion, the DEGs and hub genes with their regulatory elements identified in this study will help us understand the molecular mechanisms underlying NET and provide candidate targets for future research.

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