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MYB activity drives emergent enhancer activation and enhancer-promoter interactions in acute lymphoblastic leukemia.

Aberrant enhancer usage is a defining feature of oncogenic transcriptional reprogramming. Therapeutic strategies that disrupt enhancer-driven gene regulation may offer new treatment avenues. MYB is a key hematopoietic transcription factor that is frequently dysregulated in a broad range of cancers and plays a critical role in sustaining malignant cell states, including in aggressive leukemia subtypes such as KMT2A-rearranged leukemias. The molecular mechanisms by which it maintains oncogenic transcription remain incompletely understood. Here, we investigate the role of MYB in directing pathological enhancer activity to drive oncogene expression in leukemia. Using high-resolution Micro Capture-C, we show that upon MYB degradation, highly defined enhancer-promoter interactions at MYB binding sites are lost, correlating with the significant downregulation of target gene expression. When anchored to a gene desert region, the Myb transactivation domain (MybTA) is sufficient and necessary for the nucleation of an enhancer-like region. Critically, long-range chromatin interactions are established up to 400 kb away from where MybTA is anchored. This results in the activation of transcription from distal cryptic elements, which is reduced or abolished in the presence of point mutations that disrupt its interaction with the coactivators P300/CBP. All these results indicate that MYB activity alone is sufficient to generate an enhancer, inducing transcription through precise enhancer-promoter cross talk, and identify the MYB-P300/CBP axis as a therapeutically actionable vulnerability in enhancer-driven malignancies.

Promoter Regions, Genetic

Enhancer and super-enhancer landscape in polycystic kidney disease.

Widespread aberrant gene expression is a pathological hallmark of polycystic kidney disease (PKD). Numerous pathogenic signaling cascades, including c-Myc, Fos, and Jun, are transactivated. However, the underlying epigenetic regulators are poorly defined. Here we show that H3K27ac, an acetylated modification of DNA packing protein histone H3 that marks active enhancers, is elevated in mouse and human samples of autosomal dominant PKD. Using comparative H3K27ac ChIP-Seq analysis, we mapped over 16000 active intronic and intergenic enhancer elements in Pkd1-mutant mouse kidneys. We found that the cystic kidney epigenetic landscape resembles that of a developing kidney, and over 90% of upregulated genes in Pkd1-mutant kidneys are co-housed with activated enhancers in the same topologically associated domains. Furthermore, we identified an evolutionarily conserved enhancer cluster downstream of the c-Myc gene and super-enhancers flanking both Jun and Fos loci in mouse and human models of autosomal dominant PKD. Deleting these regulatory elements reduced c-Myc, Jun, or Fos abundance and suppressed proliferation and 3D cyst growth of Pkd1-mutant cells. Finally, inhibiting glycolysis and glutaminolysis or activating Ppara in Pkd1-mutant cells lowerd global H3K27ac levels and its abundance on c-Myc enhancers. Thus, our work suggests that epigenetic rewiring mediates the transcriptomic dysregulation in PKD, and the regulatory elements can be targeted to slow cyst growth.

Animals

ATRX Condensates as Candidate Organizers of Enhancer-Centered Nuclear Microenvironments in Neural Progenitors: A Hypothesis for Enhancer-Associated ATRX Function in Neural Progenitors.

Neural progenitor cells (NPCs) must preserve lineage identity while remaining responsive to developmental cues. Here, we discuss the hypothesis that ATRX condensates help organize enhancer-centered nuclear microenvironments in NPCs. ATRX has long been studied in heterochromatin maintenance, histone variant deposition, and chromatin remodeling; earlier work has also shown that ATRX can occupy euchromatic and active regulatory regions and contribute to transcriptional regulation. Recent evidence in human NPCs indicates that ATRX forms nuclear puncta with condensate-like properties, associates with neurogenic enhancer-rich regions, and incorporates regulatory factors such as CHD7 and p300. Perturbation of ATRX condensate formation is associated with changes in enhancer-associated ATRX occupancy, neural gene-expression programs, and neuroepithelial organization, suggesting a regulatory mode that may complement canonical heterochromatin-associated functions. We propose a dual-mode model in which folded domains contribute to chromatin anchoring at repressive regions, whereas intrinsically disordered regions support condensate-associated organization at active developmental enhancers. We emphasize that whether ATRX condensates activate enhancers de novo, stabilize pre-existing enhancer states, buffer transcriptional variability, or primarily organize cofactor localization remains unresolved. We also discuss limitations of the current evidence and outline acute, locus-specific experiments needed to test the model.

X-linked Nuclear Protein

Hi-Enhancer: a two-stage framework for prediction and localization of enhancers based on Blending-KAN and Stacking-Auto models.

MOTIVATION: Gene expression plays a crucial role in cell function, and enhancers can regulate gene expression precisely. Therefore, accurate prediction of enhancers is particularly critical. However, existing prediction methods have low accuracy or rely on fixed multiple epigenetic signals, which may not always be available. RESULTS: We propose a two-stage framework that accurately predicts enhancers by flexibly combining multiple epigenetic signals. In the first stage, we designed a Blending-KAN model, which integrates the results of various base classifiers and employs Kolmogorov-Arnold Networks (KAN) as a meta-classifier to predict enhancers based on flexible combinations of multiple epigenetic signals. In the second stage, we developed a Stacking-Auto model, which extracted sequence features using DNABERT-2 and located the enhancers based on the Stacking strategy and AutoGluon framework. The accuracy of the Blending-KAN model reached 99.69 ± 0.11% when five epigenetic signals were used. In cross-cell line prediction, the accuracy was more significant than or equal to 93.72%. With Gaussian noise, it still maintains an accuracy of 98.74 ± 0.03%. In the second stage, the accuracy of the Stacking-Auto model is 80.50%, which is better than the existing 17 methods. The results show that our models can be flexibly used to predict and locate enhancers utilizing a combination of multiple epigenetic signals. AVAILABILITY AND IMPLEMENTATION: The source code is available at https://github.com/emanlee/Hi-Enhancer and https://doi.org/10.6084/m9.figshare.29262158.v1.

Enhancer Elements, Genetic

Enhancement of 5-iododeoxyuridine-induced endogenous C-type virus activation by polycyclic hydrocarbons: apparent lack of parallelism between enhancement and carcinogenicity.

When mouse MLg cells were treated with 3-methylcholanthrene or 7,12-dimethylbenz[alpha]anthracene in the presence of microsomal enzymes and NADPH after 5-iododeoxyuridine (IUDR) treatment, the induction rate of the endogenous C-type virus was increased fivefold to sixfold in comparison with the culture treated with IUDR only. In this reaction, both the microsomal enzymes and NADPH were indispensable. 7,8-Benzoflavone, an inhibitor of the metabolism of hydrocarbons in hamster embryo cultures, inhibited the reaction. For detecting the enhancing activity, the concentration of IUDR for the pretreatment, the concentration of the test products, and the duration of the treatment with the products were important factors. In screening 30 polycyclic hydrocarbons, we were unable to detect a correlation between the in vivo carcinogenicity in the skin and the enhancing activity in the conditions tested.

9,10-Dimethyl-1,2-benzanthracene

H3K4me2 marks the enhancer: Enhancer logic in the zebrafish embryo.

At a key point in development, the embryo activates its genome: a shift that is largely coordinated by maternally derived factors. A new study in PLOS Biology identifies H3K4me2-marked enhancers in zebrafish that function independently and mirror the gamete state.

Animals

Enhancement flavor quality in Zhao'an Baxian oolong tea through enhanced turning-over process.

A systematical investigation on the effects of turning-over intensity on the flavor formation of Zhao'an Baxian oolong tea (ZBT) was performed, through a comparative analysis of heavy turning-over (HT) and light turning-over (LT) treatments in this study. The tea samples were subjected to proteomic and metabolomic analyses, combined with quantitative descriptive analysis (QDA) and electronic sensory (E-tongue/E-nose) evaluation. The results demonstrate that HT significantly reduced the content of bitter and astringent compounds, such as catechins and flavonol glycosides, while promoting the accumulation of umami-related amino acids. Concurrently, HT enhanced the biosynthesis of key floral and fruity volatiles, such as β-ocimene, geraniol, benzaldehyde, jasmone by activating stress-responsive metabolic pathways. These coordinated biochemical changes, driven by enzyme-catalyzed reactions in response to prolonged mechanical wounding and environmental stress, collectively improved the overall sensory profile of ZBT. These findings provide a mechanistic foundation for improving ZBT production, with clear implications for quality control and flavor-oriented product development.

Tea

[Spleen enhancement reactions in chick embryo after homografting adult chicken spleen fragments: changes in spleen cell population in relation to rate of spleen enhancement].

A method using the comparison between the modifications of spleen weight and on spleen smears visible modifications of the distribution into categories of cells which are classified by the mean of their maturation degree, suggested that these both types of modifications are bound. Therefore, the classic cytological study seems to be a really good tool for analysing the effects of this kind of grafting on the haemopoietic organs, the weight modifications of which are difficult to measure. On the other hand, this method allowed us to see that the distribution of the cell population in the weakly enlarged spleens is very different from both distribution of the population in the strongly enlarged spleens and the controls ones ; this heterogeneity of the stimulating effect of the graft asked us the question whether this one could exerce its influence by the mean of two different ways, at least, or by only one.

Animals

dbscATAC: a resource of single-cell super-enhancers/enhancers and gene markers derived from scATAC-seq data.

MOTIVATION: scATAC-seq enables high-resolution mapping of cis-regulatory elements. It has been widely applied to uncover cell-type-specific regulatory networks and complement scRNA-seq analysis in numerous studies. However, a large number of datasets generated by scATAC-seq remain underutilized due to limited exploration of super-enhancers/typical enhancers and gene markers. A comprehensive resource enabling cell-type-specific annotation of cis-regulatory elements and their dynamic enhancer-gene linkages remains an urgent unmet need for scATAC-seq. RESULTS: We present dbscATAC, a specialized single-cell database for annotating super-enhancers, gene markers, and enhancer-gene interactions derived from scATAC-seq data. Using improved machine learning algorithms, we identified 213 835 super-enhancers across 520 tissue/cell types from three species, as well as 347 484 gene markers, 13 470 526 enhancers, and 10 402 346 enhancer-gene interactions derived from 1 668 076 single cells spanning 1028 tissue/cell types in 13 species. An easy-to-use online platform with multiple analytic modules and hierarchical query options was developed for searching, browsing and visualizing single-cell super-enhancers, enhancers, and gene markers. dbscATAC provides a comprehensive resource to facilitate the exploration of enhancer landscapes, gene regulation, and cell-type-specific characteristics in single-cell epigenomics. AVAILABILITY AND IMPLEMENTATION: The database with all the super-enhancer/enhancer annotation data is available at http://singlecelldb.com/dbscATAC/index.php. And the source code of dbscATAC for prediction of SEs, enhancers, and gene markers are available at https://github.com/EvansGao/dbscATAC. The source code, tissue/cell type description, and data summary can be downloaded at DOI: 10.6084/m9.figshare.28706414.scATAC-seq, Database, Super-enhancers/enhancers, Gene markers.

Enhancer Elements, Genetic

An encyclopedia of human enhancer-gene regulatory interactions.

Identifying transcriptional enhancers and their target genes is essential for understanding gene regulation and the effect of human genetic variation on disease1-6. Here we create and evaluate a resource of more than 92 million enhancer-gene regulatory interactions across 1,458 biosamples covering 369 cell types and tissues, by integrating predictive models, chromatin states, three-dimensional contacts and large-scale genetic perturbations generated by the ENCODE Consortium7. We first create a systematic benchmarking pipeline to compare predictive models, assembling a dataset of 10,356 element-gene pairs measured in CRISPR perturbation experiments, more than 30,000 fine-mapped expression quantitative trait loci and 569 fine-mapped genome-wide association study (GWAS) variants linked to a probable causal gene. Using this framework, we develop ENCODE-rE2G, a predictive model achieving state-of-the-art performance across several prediction tasks, demonstrating that iterative perturbations and supervised machine learning can build increasingly accurate predictive models of enhancer regulation. Using ENCODE-rE2G, we build an encyclopedia of enhancer-gene regulatory interactions in the human genome, revealing global properties of enhancer networks, identifying differences in regulatory complexity across genes and improving analyses linking noncoding variants to target genes and cell types for common complex diseases. By interpreting the model, we find that beyond enhancer activity and three-dimensional enhancer-promoter contacts, additional features that guide enhancer-promoter communication include promoter class and enhancer-enhancer synergy. These genome-wide maps of enhancer-gene regulatory interactions, benchmarking software, predictive models and insights about enhancer function provide a valuable resource for future studies of gene regulation and human genetics.

Humans

A genome-wide survey reveals a diverse array of enhancers coordinate the Drosophila innate immune response.

To defend against microbes, animals regulate a complex immune response. The Drosophila innate immune system deploys a large transcriptional induction of signaling proteins, antimicrobial effectors, and other critical immune factors. This transcriptional response is encoded in enhancers, cis-regulatory sequences that modulate gene expression by binding transcription factors (TFs). While enhancers and transcription factor binding sites (TFBS) have been identified for several immune responsive genes in Drosophila, most enhancers that regulate immune-induced genes are unknown. By identifying enhancers, we can understand how their composition controls expression and contributes to infection outcome. We employed STARR-seq (Self Transcribing Active Regulatory-Region sequencing) in a hemocyte-like cell line to identify immune-specific enhancers across the D. melanogaster genome and performed ATAC-seq in hemocytes extracted from adult flies to assess the chromatin state of these enhancers before and after immune stimulus. We identified thousands of enhancers responsive to IMD stimulation, one of the two primary immune signaling pathways in Drosophila. As expected, immune enhancers are enriched for motifs of Relish, an NF-κB factor, and Kay/Jra, a bZip heterodimer pair, involved in the Imd and JNK pathways respectively, compared to enhancers active in unstimulated cells. However, when grouping enhancers by their target gene's expression timing or functional role or by the enhancers' chromatin accessibility pre- or post-stimulus, different groups of TFBS motifs are enriched, suggesting distinct regulatory logic for different parts of the immune response. Identification and characterization of the diverse array of enhancers that regulate the innate immune response expands our understanding of how animals fight infections.

Drosophila immunity

Genomic Language Model for Predicting Enhancers and Their Allele-Specific Activity in the Human Genome.

Predicting and deciphering the regulatory logic of enhancers is a challenging problem, due to the intricate sequence features and lack of consistent genetic or epigenetic signatures that can accurately discriminate enhancers from other genomic regions. Recent machine-learning based methods have spotlighted the importance of extracting nucleotide composition of enhancers but failed to learn the sequence context and perform suboptimally. Motivated by advances in genomic language models, we developed DNABERT-Enhancer, a novel enhancer prediction method, by applying DNABERT pre-trained language model on the human genome. We trained two different models, using large collection of enhancers curated from the ENCODE registry of candidate cis-Regulatory Elements. The best fine-tuned model achieved 88.05% accuracy with Matthews correlation coefficient of 76% on independent set aside data. Further, we present the analysis of the predicted enhancers for all chromosomes of the human genome by comparing with the enhancer regions reported in publicly available databases. Finally, we applied DNABERT-Enhancer along with other DNABERT based regulatory genomic region prediction models to predict candidate SNPs with allele-specific enhancer and transcription factor binding activity. The genome-wide enhancer annotations and candidate loss-of-function genetic variants predicted by DNABERT-Enhancer provide valuable resources for genome interpretation in functional and clinical genomics studies.

Journal Article

Progesterone receptor isoform modulation via enhancer activation regulates progesterone signaling in endometrial stromal cells.

OBJECTIVE: To investigate enhancer-mediated regulation of progesterone receptor (PGR) isoforms, PGR-A and PGR-B, in human endometrial stromal cells, and to determine how isoform modulation shapes the progesterone-responsive transcriptome and cistrome relevant to endometrial function. DESIGN: A clustered regularly interspaced short palindromic repeats-based functional genomic screen was used to identify distal enhancers in telomerase-immortalized human endometrial stromal cells. Subsequent clustered regularly interspaced short palindromic repeats targeting of identified enhancers and the PGR promoter was used to modulate PGR isoform balance and assess functional consequences. SUBJECTS: None. EXPOSURE: Engineered endometrial stromal cells were treated with medroxyprogesterone acetate or vehicle. MAIN OUTCOME MEASURES: PGR isoform expression was assessed by western blot, the progesterone-responsive transcriptome was characterized by bulk ribonucleic acid sequencing, and the PGR cistrome was characterized by Cut&Run. RESULTS: Two distal PGR enhancers were identified in endometrial stromal cells located approximately 60 and 220 kb upstream of the PGR transcription start site. Clustered regularly interspaced short palindromic repeats-based activation of these enhancers upregulated both PGR-A and PGR-B, whereas promoter activation primarily upregulated PGR-B. Bulk ribonucleic acid sequencing revealed that shifting the PGR isoform balance altered the progesterone-regulated transcriptome: PGR-A/B-equivalent cells exhibited proinflammatory gene signatures, whereas PGR-B-dominant cells demonstrated suppression of inflammatory signaling and altered cell cycle programs. The PGR Cut&Run profiling revealed distinct genomic binding patterns associated with each isoform profile. Integration of the PGR cistrome with chromatin interaction maps suggested that these isoforms directly regulate distinct gene subsets involved in inflammation and fibrosis. Mechanistically, estrogen receptor alpha (ESR1) indirectly activated PGR-A expression, potentially through recruitment of Forkhead box protein O1 (FOXO1) at the distal enhancer, suggesting a noncanonical, enhancer-mediated mechanism of PGR regulation. CONCLUSIONS: Distal enhancers regulate the PGR isoform balance and shape the progesterone-responsive transcriptome in human endometrial stromal cells. This enhancer-mediated mechanism expands current models of PGR regulation beyond promoter-level control and may offer potential therapeutic targets to restore normal progesterone responsiveness in conditions marked by PGR isoform imbalance.

Humans

Combined effects of Ret coding and enhancer loss-of-function alleles cause progressive loss of inhibitory motor neurons in the enteric nervous system.

Hirschsprung disease (HSCR) is a congenital enteric neuropathy caused by disrupted development of enteric neural crest-derived cells (ENCDCs). Although pathogenic coding variants in RET account for many cases, the largest genetic contribution to HSCR risk arises from a common noncoding variant (rs2435357) within a SOX10-bound RET enhancer (MCS+9.7) that reduces RET gene expression in vivo and triggers expression changes in other ENS genes in the human fetal gut. However, the ENS cell types affected by this enhancer and the mechanisms by which these transcriptional changes lead to HSCR remain unknown. Here, we investigated the role of this enhancer by generating mice carrying a deletion of the orthologous Ret mcs+9.7 enhancer (Δmcs+9.7). Single-cell RNA sequencing of E14.5 embryonic gut demonstrated that enhancer deletion reduced Ret expression by 8% without altering ENS cell composition. However, reduced Ret expression was restricted to differentiating neurons and inhibitory motor neuron lineages, revealing cell type-specific enhancer activity. To determine the functional consequences of further reducing Ret dosage, we generated compound heterozygous mice carrying both the enhancer deletion and a Ret coding null allele (+/Δmcs+9.7;+/CFP). These mice exhibited additive reductions in Ret expression, altered Sox10 expression, dysregulation of cell-cycle and neuronal differentiation programs, and selective depletion of developing inhibitory motor neuron lineages. These findings establish a cell type-specific role for the mcs+9.7 enhancer in modulating Ret dosage and reveal how subtle enhancer perturbations alter neural subtype specification without overt hypoganglionosis, suggesting that HSCR arises from a cascade of cellular defects triggered by >50% loss of Ret function.

Journal Article

Enhancer-mediated DDIT4 activation by SMYD2-dependent H3K4me1 promotes pazopanib resistance in clear cell renal cell carcinoma.

BACKGROUND: The progression and resistance to targeted therapy, including pazopanib, frequently lead to poor prognosis in clear cell renal cell carcinoma (ccRCC) patients. However, the underlying molecular mechanisms of these processes remain unclear. METHODS: In this study, we first performed RNA-seq to identify genes that were differentially expressed in both SMYD2-knockdown and pazopanib-resistant cells, indicating their potential role in SMYD2-mediated drug resistance. We analyzed TCGA-KIRC data and 150 patient samples to identify the relationship between SMYD2 and DDIT4 expression levels, as well as the prognostic significance of DDIT4. In vitro functional assays and murine models were applied to evaluate the effects of SMYD2 and DDIT4 on tumor growth and on pazopanib resistance. CUT&Tag and chromosome conformation capture (4 C) assays were applied to identify enhancers associated with SMYD2-mediated regulation of DDIT4, while the JASPAR database was utilized to predict transcription factors involved in the enhancer regulation. CRISPR-mediated enhancer deletion and ChIP-qPCR were subsequently performed to validate the regulatory roles of the identified enhancer and the transcription factor SPI1 in DDIT4 expression. RESULTS: Our study revealed that the expression level of DDIT4 is positively correlated with SMYD2. DDIT4 is highly expressed in renal cell carcinoma and is associated with poorer survival outcomes. Further research revealed that SMYD2 regulates H3K4me1 in a DDIT4 distal enhancer (chr10:72830412-72830891), promoting the recruitment of the transcription factor SPI1, thereby activating DDIT4 expression. We found that DDIT4 promotes the proliferation, metastasis, and pazopanib resistance of ccRCC, and DDIT4 knockdown enhances drug sensitivity in both in vitro and in vivo experiments. Furthermore, the SMYD2-DDIT4 axis activates the downstream STAT3 signaling pathway, thereby promoting tumor progression. In addition, DDIT4-related prognostic features showed potential associations with patient survival and predicted drug sensitivity in computational analyses. CONCLUSIONS: Our study identifies a previously unrecognized SMYD2-enhancer-DDIT4 regulatory axis, which promotes tumor progression and pazopanib resistance in ccRCC. These findings may provide potential therapeutic implications to overcome pazopanib resistance and improve treatment outcomes in ccRCC by targeting the SMYD2-enhancer-DDIT4 axis.

Carcinoma, Renal Cell