Search Results (1,982)

Chromatin architecture is a central determinant of genomic stability. Effective DNA repair requires dynamic chromatin remodeling to grant repair factors timely access to lesions and to orchestrate repair pathway choice. Disruption of chromatin-regulatory mechanisms or DNA damage response pathways undermines repair fidelity and contributes to a wide spectrum of human disorders, including developmental syndromes, premature aging, and multiple cancers. Here, we review how chromatin state and remodeling complexes shape detection, signaling, and resolution of DNA double-strand breaks, and we examine how their misregulation drives disease and presents opportunities for therapeutic intervention. Specifically, we discuss how post-translational modifications and ATP-dependent chromatin remodeling complexes contribute to DNA damage repair with a particular focus on DNA double-strand breaks, one of the most deleterious DNA lesions. We summarize how chromatin remodeling and histone post-translational modifications regulate DNA repair pathway choice, and how these processes are essential for safeguarding genomic integrity and preventing human disease. Finally, we discuss emerging concepts and major unanswered questions in the context of chromatin function and DNA double-strand break repair, with a focus on exploring the emerging literature on the role of chromatin compartments and topological associated domains for orchestrating DNA repair within chromatin and safeguarding genomic stability. Full article

Nucleoside analogs (NAs) play a central role in cancer therapy, either through direct cytotoxicity or epigenome reprogramming. They are clinically effective but have shortcomings in their long-term effectiveness because of variable patient responses and the emergence of resistance. There is growing evidence that DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs (ncRNAs) are key factors that determine sensitivity and resistance to NAs. This review summarizes existing evidence on the epigenetic control of cytotoxic and epigenetic nucleoside analogs, discusses predictive biomarkers of human Equilibrative Nucleoside Transporter 1 (hENT1) and deoxycytidine kinase (dCK) promoter methylation, histone modifications, and ncRNA signatures, and assesses the emerging strategies of multi-omic integration. Improvements in detection methods, such as high-resolution sequencing, single-cell profiling, and liquid biopsy, are addressed, along with the issues of reproducibility, tumor heterogeneity, and clinical translation. Epigenetic biomarkers are promising for patient stratification in clinical trials, although a lack of uniformity in technical and methodological approaches currently constrains their full potential. The future focus will be on standardized panels of biomarkers, real-time monitoring, rational combination strategies, and biomarker-directed clinical trial designs. Overall, epigenetic biomarkers are capable of changing nucleoside analog therapy into a more precise, durable, and personalized treatment approach. Full article

Prostate cancer is a major cause of cancer-related deaths among men in Sub-Saharan Africa, where late-stage diagnoses are common due to limited access to affordable and sensitive diagnostic tools. Early detection is essential to improve survival and reduce the disease burden. This review explores the integration of epigenetic biomarkers and CRISPR-Cas12a technology as a transformative approach for early, non-invasive prostate cancer detection in resource-limited settings. Among the many complexities of cancer development, molecular dysregulation plays a critical role. Epigenetic modifications including DNA methylation, histone changes, and non-coding RNA expression have emerged as stable and specific biomarkers with significant potential for the early detection and characterisation of prostate carcinogenesis. However, their low concentration in body fluids poses a significant challenge for detection. CRISPR-Cas12a, renowned for its high specificity and sensitivity, offers a promising solution. When integrated with isothermal amplification and liquid biopsy techniques, it enables rapid, point-of-care diagnostics. This review proposes a CRISPR-Cas12a-based diagnostic pipeline for the detection of specific epigenetic markers in liquid biopsies that could be associated with prostate cancer. The adoption of this technology in Sub-Saharan Africa has the potential to significantly improve early diagnosis, reduce mortality, and promote health equity. Full article

Inflammatory and autoimmune diseases are now understood to be significantly influenced by the intricate interactions between the microbiome and host physiology. This review investigates the function of epigenetic dysregulation in microbiome–host interaction and its consequences for health and disease. Epigenetic modifications, including DNA methylation, histone modifications, and non-coding RNA-associated regulation, are key mechanisms that control gene expression without altering the underlying DNA sequence. Microbial metabolites and community composition alterations can cause disruptions in these epigenetic processes, resulting in dysregulated immune responses and the initiation of chronic inflammatory conditions. In particular, the diversity of gut microbiota alters host epigenetic patterns, affecting T cell differentiation, inflammatory modulation, and tissue homeostasis. Aberrant epigenetic modifications contribute to the pathogenesis of autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) by promoting inflammation and autoimmunity. Similarly, gut microbiota dysbiosis has been implicated in the development and progression of inflammatory bowel disease (IBD). Identifying the reciprocal interaction between epigenetic alterations and microbiome dynamics provides unique insights into therapeutic options targeted at restoring microbial homeostasis to prevent disease progress. Consequently, understanding the intricacies of epigenetic dysregulation in microbiome–host interactions represents a significant sector in biomedical research and highlights the promise for precision medicine approaches in treating inflammatory and autoimmune diseases. The potential for microbiome-based therapies to affect host epigenetic landscapes requires additional research, paving the way for innovative therapeutic paradigms targeted at improving host resilience and restoring immunological balance. The purpose of this review is to synthesize current knowledge on how epigenetic dysregulation and microbiome–host interactions drive inflammatory and autoimmune diseases and to highlight emerging therapeutic opportunities. Full article

Colorectal cancer is a heterogeneous malignancy characterized by alterations in oncogenic signaling pathways and epigenetic mechanisms involved in gene regulation. Aberrant activation of the Wnt/β-catenin pathway represents a central molecular event in colorectal tumorigenesis, while histone-associated epigenetic modifications may contribute to tumor progression and variability. This study aimed to investigate the relationship between Wnt pathway activation and histone H3 lysine 27 trimethylation in colorectal cancer and to examine their associations with clinicopathological and molecular characteristics. A retrospective observational study was performed on 83 colorectal adenocarcinoma cases using immunohistochemical evaluation of nuclear β-catenin and H3K27me3 expression in formalin-fixed, paraffin-embedded tumor samples, together with molecular analysis of KRAS, NRAS, and BRAF mutations and microsatellite instability status. Nuclear β-catenin expression was observed in 39.8% of cases, while H3K27me3 exhibited negative, mosaic, or diffuse nuclear staining patterns. Nuclear β-catenin expression was significantly associated with patient sex and age, whereas H3K27me3 expression patterns were significantly associated with tumor location, histological grade, disease stage, and metastatic status. These results indicate that Wnt pathway activation and H3K27me3-associated epigenetic alterations frequently coexist in colorectal cancer and support the value of integrated molecular and epigenetic assessment. Full article

Erythropoiesis is tightly regulated by lineage-specific transcription factors that govern erythroid commitment, proliferation, and differentiation. A core erythroid transcriptional network, together with non-DNA-binding cofactors, occupies regulatory regions of genes essential for erythroid development. This process is further shaped by epigenetic mechanisms, including histone post-translational modifications and long-range chromatin interactions. CCCTC-binding factor (CTCF) is a multifunctional regulator with a central role in three-dimensional chromatin organization. Although CTCF has been implicated in hematopoietic differentiation and leukemogenesis, its specific function in erythropoiesis remains poorly defined. Here, we investigated the role of CTCF during erythroid differentiation using two complementary models: pluripotent K562 leukemia cells and primary human CD34⁺ hematopoietic stem/progenitor cells, each induced toward the erythroid lineage by distinct stimuli. In both systems, CTCF silencing impaired erythroid differentiation by repression of key erythroid transcription factor genes, including LMO2, KLF1, MYB, and ETS1. This repression was associated with enrichment of repressive histone marks at CTCF-binding sites within their regulatory regions. Moreover, CTCF cooperated with cohesin to establish and stabilize long-range chromatin interactions at these loci. These results provide new insight into how CTCF-dependent chromatin regulation contributes to normal erythroid development and suggest that perturbation of this regulatory axis may have implications for hematopoietic disorders and malignancies. Full article

Alpha-Ketoglutarate (AKG), a central intermediate of the tricarboxylic acid cycle, is a crucial metabolic and signaling molecule that connects mitochondrial function with cellular homeostasis, immunological modulation, epigenetic remodeling, and lifespan. While mitochondrial AKG maintains energy metabolism, the nuclear AKG pool influences chromatin remodeling through DNA and histone modifications, which together control hypoxia responses and shape gene expression patterns. This dual role demonstrates AKG’s significance in mediating metabolic state, gene expression, and long-term cellular adaptability. AKG modulates immunological responses, reduces reactive oxygen species (ROS), promotes the polarization of anti-inflammatory macrophages, and suppresses nuclear factor kappa B (NF-κB) activation, thereby reducing chronic inflammatory processes. AKG restricts pro-inflammatory cytokine production, increases extracellular matrix synthesis, and reduces cartilage degradation in arthritic models, suggesting potential therapeutic benefits in autoimmune diseases and joint degeneration. Additionally, AKG affects lifespan in several model organisms, where supplementation enhances metabolic resilience, lowers age-related inflammation, modifies mTOR signaling, and preserves youthful epigenetic profiles. Additionally, because endogenous AKG levels decrease with age, oral supplementation of AKG, especially with calcium and arginine, has drawn attention to its potential benefits in longevity and metabolic health. Thus, AKG is versatile and has encouraging therapeutic promise for cancer, aging, and inflammatory illnesses. However, a lack of human clinical evidence prompts further research to determine ideal dosage, tissue selectivity, and long-term safety. The goal of this review is to critically examine the current mechanistic knowledge related to AKG biosynthesis and breakdown and its future implications in maintaining cellular homeostasis and controlling chronic inflammation. Full article

Alveolar macrophages (AMs) play essential roles in maintaining homeostasis and immunity in the lung. The transcription factor PU.1, encoded by SPI1, is a core regulator in multiple immune cell lineages. However, its binding property and regulatory role in AMs remain unclear. The pig serves as an important livestock species and a valuable biomedical model. Using porcine AMs (PAMs) as a model, we combined gene knockdown experiments with multiomic profiling to elucidate the regulatory role of PU.1 in AMs. By integrating the RNA-seq data before and after SPI1 knockdown, we demonstrate that disruption of PU.1 impairs the expression of numerous immune-related genes, including many crucial for innate immune responses. We further employed CUT&Tag to characterize the genome-wide occupancy of PU.1 and the active histone modification H3K27ac, and found that PU.1 primarily binds active cis-regulatory elements (CREs), including a large proportion of enhancers derived from transposable elements. Moreover, integrative analysis identifies a set of CREs and their associated genes, which are putative direct targets of PU.1. Overall, this study provides novel insights into the regulatory role of PU.1 in AMs and extends our knowledge about this core regulator in the mammalian immune system. Full article

Background/Objectives: Many chronic diseases, including cancer, can be developed in conjunction with excessive intracellular oxidative stress and persistent inflammation. The importance of preventive strategies is highlighted by the potential of phytochemical interventions to mitigate these diseases. The purpose of this study was to investigate how Citrus depressa leaf (CDL) extracts can prevent 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced carcinogenesis in JB6 P+ mouse skin epidermal cells. Methods: CDL extracts were prepared and characterized for their phenolic and flavonoid contents. Effects of the potent extract on cell viability, TPA-induced colony formation, intracellular reactive oxygen species (ROS) levels, and nuclear factor erythroid 2–related factor 2 (Nrf2)-related protein and mRNA expression, mediated by epigenetic modifications, were evaluated in JB6 P+ cells. Results: Both the water extract (CDL-WE) and the 95% ethanol extract (CDL-95EE) contain abundant flavonoids that inhibit TPA-induced cell transformation and colony formation without minimal cytotoxicity. Mechanistic studies indicated that CDL-95EE increased the gene expression of Nrf2-related detoxification and antioxidant enzymes, such as UDP-glucuronosyltransferase 1A (UGT1A) and heme oxygenase-1 (HO-1), and decreased intracellular ROS accumulation. Furthermore, CDL-95EE reduced the expression of epigenetic modifiers, including DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), suggesting involvement in epigenetic regulation. Conclusions: These findings indicate that CDL, an agricultural by-product, may be useful in cancer prevention through antioxidant and epigenetic mechanisms. Full article

Tooth development or odontogenesis is a complex morphogenetic process that requires tightly regulated interactions between the oral epithelium and mesenchyme of neural crest origin. In this narrative review, we compile existing knowledge regarding gene regulatory networks and epigenetic factors throughout tooth development from initiation to eruption. Signaling between the epithelium and mesenchyme is mediated by four conserved pathways—Wnt/β-catenin, bone morphogenetic protein (BMP), fibroblast growth factor (FGF), and Sonic hedgehog (Shh)—which operate iteratively and interact through extensive crosstalk at each developmental stage. Transcription factors, such as PAX9, MSX1, PITX2, and LEF1, interpret these signals to control cell fate decisions and differentiation. Epigenetic modifications, including DNA methylation, histone modifications, and microRNA-mediated regulation, provide additional layers of control that fine-tune gene expression programs. Unlike existing reviews that address these regulatory mechanisms separately, here we integrate signaling pathways, transcription factor networks, epigenetic regulation, human genetic disorders, dental stem cell biology, and recent single-cell transcriptomic insights into a unified framework. We discuss opportunities to apply developmental biology knowledge towards regenerative dentistry goals, including iPSC-derived dental models and spatially resolved multi-omics approaches, while acknowledging the considerable gap between preclinical findings and clinical applications. Full article

Breast cancer (BC), a multifactorial condition, remains one of the most common malignancies in women, in which the majority of BCs are hormone-sensitive and are activated by estrogens, especially 17β-estradiol (E2). Whereas aromatization of androgens to estrogens is achieved by the aromatase enzyme, the steroidogenic acute regulatory (StAR) protein, by mobilizing the transport of intra-mitochondrial cholesterol, plays an indispensable role in E2 biosynthesis. Accumulating evidence indicates that aromatase expression is aberrantly high and analogous in normal and malignant breast tissues, even though endocrine therapy, based on aromatase inhibitors (AIs), has been the mainstay of BC treatment in post-menopausal women. Despite the beneficial effects of AIs, their long-term usage has been associated with undesirable long-term side effects, including endocrine resistance, which is the leading cause of cancer death, warranting an improved therapy for mitigating this devastating disease. Along these lines, we reported that StAR is differentially expressed, along with E2 biosynthesis, in human and mouse cancerous and non-cancerous breast cells and tissues, in which we discovered that StAR is an acetylated protein, in addition to the identification of a number of lysine residues, undergoing acetylation and deacetylation, suggesting the importance of this newly uncovered StAR modification in E2 regulation in mammary tissue. One of the current therapeutic approaches for BC is targeting with histone deacetylase inhibitors (HDACIs), as these epigenetic enzymes control multiple cellular processes, including chromatin remodeling and genomic stability through the dynamic process of acetylation and deacetylation of core histones. Concomitantly, we have demonstrated that several HDACIs, including FDA-approved HDACIs, at therapeutically and clinically relevant doses, alter StAR acetylation patterns and suppress E2 accumulation in both hormone-sensitive human BC and mouse primary cultures of breast tumor epithelial cells. This review provides the molecular insights into breast pathogenesis and its therapeutics, and proposes that a combination therapy involving AI and HDACI, targeting aromatase and StAR, respectively, suppresses intra-tumoral E2 accumulation and limits antagonistic side effects, and these measures are beneficial for the prevention and/or management of hormone-sensitive BC. Full article

The limited and inconsistent efficacy of existing therapies for tuberous sclerosis complex (TSC) has driven the exploration of novel strategies, including epigenetic regulation. GSK-J4, an inducer of global H3K27me3 accumulation, shows broad anti-tumor activity. However, its therapeutic potential in TSC remains unclear. In the study, we reported that GSK-J4 inhibited cell cycle progression and induced apoptosis in primary Tsc1^+/− and Tsc2^+/− MEFs. Mechanistically, Tsc1 or Tsc2 deletion reduced global H3K27me3, correlating with increased viability, accelerated cell cycle, and suppressed apoptosis-phenotypes reversed by GSK-J4. Moreover, GSK-J4 triggered endoplasmic reticulum stress (ERS) by activating the PERK-ATF4-CHOP axis, which concurrently downregulated the proto-oncogene c-Myc, outlining a GSK-J4→p-PERK→c-Myc inhibitory pathway. Notably, GSK-J4 synergized with rapamycin to enhance cell cycle arrest and apoptosis. In vivo, this combination alleviated renal impairment in Tsc1- or Tsc2-deficient models, suggesting a promising therapeutic strategy for TSC patients with suboptimal response to mammalian target of rapamycin complex 1 (mTORC1) inhibitors. Our study elucidates a specific ERS-dependent anti-tumor mechanism of GSK-J4 in Tsc-deficient contexts and demonstrates the synergistic efficacy of combining epigenetic and mTORC1 inhibitors. Full article

Background: Gene expression and cellular identity are regulated by epigenetics that occurs through chromatin modifications, RNA changes, chromatin accessibility, and three-dimensional genome organization. Although DNA methylation has been the focus of most epigenetics studies in the past, other non-methyl epigenetic processes, including histone post-translational modifications (PTMs), epitranscriptomic marks, and chromatin remodeling, are dynamic, reversible, and context-dependent, and thus are difficult to accurately interrogate using endpoint sequencing-based assays, especially in heterogeneous tissues, developing systems, and therapeutic response environments. Scope and Approach: The present review discusses epigenetic modifications other than DNA methylation regarding sensor-based technologies that can measure live, dynamic, and spatially resolved measurements. Epigenetic sensors include any genetically encoded sensors (GECs) based on resonance energy transfer, CRISPR/dCas-derived sensors, or aptamer-based sensors, and hybrid biochemical/imaging sensors that can be used in live or semi-live settings. It lays emphasis on the technologies, which have been developed recently, that allow real-time kinetic measurements, working in three-dimensional and organoid models, and being applied to disease-relevant perturbations. On these platforms, performance properties such as specificity, sensitivity, spatial and temporal resolution, ability to perform dynamic versus locus-specific interrogation, and perturbed endogenous chromatin states are compared. Key Conclusions and Outlook: Together, these sensing strategies are complementary to the traditional methods of measuring epigenomics in that they show epigenetic dynamics unobservable with static measurements. We list the important technical issues, including specificity, quantitation, multiplexing, and chromatin perturbation, and report the barriers and solutions in development and design. Lastly, we provide a conceptual map of how live epigenetic sensing and multi-omics and translational models can be integrated, and how the two methodologies can be used to develop functional epigenetics and guide disease modeling and drug development. Full article

Diverse epigenetic regulatory mechanisms ensure and modulate cellular diversity. The histone 3 lysine 9 me3 (H3K9me3) post-translational modification participates in silencing lineage-inappropriate genes by restricting access of transcription factors and other regulatory proteins to genes that control cell fate. Mouse olfactory sensory neurons (OSNs) select one olfactory receptor (OR) gene out of 2600 possibilities. This monoallelic and stochastic OR choice occurs as OSNs differentiate and undergo dramatic changes in nuclear architecture. OR genes from different chromosomes converge into specialized nuclear bodies and chromatin compartments, as H3K9me3 and chromatin binding proteins including heterochromatin protein 1 (HP1) are incorporated. In this work, we have uncovered an unexpected role for HP1β in OR choice and neuronal identity that cannot be rescued by HP1α in vivo. With the use of a conditional knock-in mouse model, that after CRE expression replaces HP1β with HP1α, we observe changes in H3K9me3 levels and DNA accessibility over OR gene clusters. These changes alter the expression patterns that partition the mouse olfactory epithelium into five OR expression zones, which results in a reduced OR repertoire that leads to a loss of olfactory sensory neuron diversity. We propose that HP1β modulates the competition of OR promoters for enhancers to promote receptor diversity by establishing repression gradients in a zonal fashion. Full article

Lysine propionylation (Kpr) is a metabolically coupled lysine acylation that links propionyl-CoA availability to the molecular regulation of gene expression and protein function. Although lysine acetylation (Kac) is the most extensively characterized, recent proteomic and metabolic studies suggest that Kpr is more frequent than previously appreciated, occurs at defined lysine sites, and displays tissue-resolved and context-dependent patterns. Kpr often co-varies with other short-chain acylations such as Kac and lysine butyrylation (Kbu); however, emerging genomic-scale evidence indicates mark-biased genomic distributions and functional associations, suggesting that Kpr is not simply an extension or alternative to Kac. Notably, propionyl-CoA, the direct acyl donor for Kpr, can be influenced by microbiome-derived short-chain fatty acids (SCFAs), implying that interventions modulating SCFA availability (e.g., dietary manipulation) may provide an actionable route to tune Kpr and related acylations. Here, we summarize recent advances in propionyl-CoA sources and compartmentalization, the enzymatic writers/erasers/readers, the molecular mechanisms underlying Kpr, and the functional consequences of Kpr in physiology and disease. Full article