Search Results (487)

Background/Objectives: Oral squamous cell carcinoma (OSCC) is a common and aggressive oral cancer with high recurrence and mortality rates, largely due to late diagnosis and metastasis. Epigenetic regulation, particularly aberrant DNA methylation, plays a critical role in cancer progression. Altered methylation patterns disrupt cancer-related gene regulation. Our previous study found that oral cancer patients exhibit increased synthesis of S-adenosyl-L-methionine, a key methyl donor for cytosine methylation. Therefore, the aim of this study was to explore the relationship between global DNA methylation and OSCC progression and to evaluate the impact of DNA methylation heterogeneity on oral cancer cells. Methods: Immunohistochemistry (IHC) and immunofluorescence (IF) staining were used to examine 5-methylcytosine (5-mC) expression in OSCC clinical specimens and oral cancer cells. The DNA methyltransferase inhibitor 5-Aza-dC was used to assess the effects of DNA methylation on cell function and gene expression. RNA sequencing was used to identify key differentially expressed genes affected by 5-Aza-dC treatment. Cell migration was assessed using a wound closure assay. Protein and gene expression were analyzed using Western blotting and quantitative PCR. Results: An inverse relationship was found between 5-mC levels and cancer differentiation—poorly differentiated OSCC exhibited higher 5-mC levels. Additionally, higher 5-mC staining was observed at the invasion front of oral cancer tissues. In OSCC cells, 5-mC content correlated with migration ability. Furthermore, conditioned medium from cancer-associated fibroblasts enhanced both methylation levels and migration of OSCC cells. Treatment with 5-Aza-dC significantly increased epithelial differentiation, reduced epithelial-to-mesenchymal transition and cell adhesion-related genes, and inhibited OSCC cell migration. Conclusions: The findings highlight the critical role of DNA hypermethylation in OSCC progression, particularly in regulating differentiation, migration, and EMT. The interplay between the tumor microenvironment and epigenetic modifications underscores the complexity of OSCC biology and opens avenues for innovative therapeutic strategies. Full article

N⁶-methyladenosine (m⁶A) is the most abundant modification of mRNA and plays a crucial role in mediating cellular functions, and it is associated with cancer and neurodegenerative diseases. Studies have shown that m⁶A is predominantly deposited on its consensus motif by the m⁶A writer proteins RNA methyltransferase METLL3/METLL14. However, it was found that nonconventional m⁶A deposition by other alternative pathways may also exist and can modulate epitranscriptomic regulation in cells. Thus, understanding the molecular mechanisms underlying nonconventional m⁶A deposition outside the canonical motifs will provide novel insights into the full scope of the functional impact of m⁶A. In this study, we discovered that m⁶ATP was efficiently incorporated by the repairing DNA polymerases pol β and pol η through RNA gap-filling synthesis on an RNA-DNA hybrid. Steady-state kinetics results showed that m⁶ATP was incorporated into RNA by the DNA polymerases with a comparable efficiency to ATP. AlphaFold3-assisted molecular dynamics simulations further elucidated the structural basis for the DNA polymerases to incorporate m⁶ATP into the RNA substrates by showing that the enzymes employed the unique base-stacking mechanism to govern the distance between the 3′-OH group of the 3′-terminus nucleotide of the primer and the 5′-α-phosphate of m⁶ATP to perform their catalysis. Furthermore, we detected a significant amount of m⁶ATP in human cells. We showed that the m⁶ATP level was associated with that of the oxidative stress biomarker 8-oxoGTP in cells, suggesting that unscheduled m⁶A deposition on RNA can be mediated by m⁶ATP incorporation that is associated with cellular oxidative stress. Our study sheds light on the unscheduled m⁶A deposition as a potential alternative mechanism for altering epitranscriptomic modifications. Full article

N⁶-methyladenosine (m⁶A) is the most prevalent internal modification in eukaryotic messenger RNA (mRNA) and plays a vital role in post-transcriptional gene regulation. In recent years, m⁶A has emerged as a pivotal epitranscriptomic signal involved in neural development, synaptic remodeling, and the molecular pathophysiology of neuropsychiatric disorders. In this review, we summarize the mechanisms underlying the deposition, removal, and recognition of m⁶A by dedicated methyltransferases, demethylases, and RNA-binding proteins. We further explore how these dynamic modifications influence neuronal differentiation and memory formation. Recent studies have linked aberrant m⁶A regulation to psychiatric conditions such as depression, anxiety, schizophrenia, and bipolar disorder. Additionally, we discuss how pharmacological or genetic modulation of m⁶A pathways may promote adaptive neural plasticity and enhance cognitive and emotional resilience. Despite these promising findings, significant challenges remain in achieving spatial and temporal specificity while minimizing off-target effects in the brain. Therefore, we advocate for more in-depth investigations into m⁶A function within developmentally defined neural circuits to better understand its enduring role in maintaining neural homeostasis. Full article

Over recent years, epitranscriptomic research has provided a new layer of gene regulation during hematopoietic development and aberrant hematopoiesis. Among the 170 identified RNA chemical marks, N⁶-methyladenosine (m⁶A) is the most abundant in eukaryotic cells and plays a critical role in various biological processes. This dynamic modification is regulated by a series of methyltransferases, demethylases, and m⁶A binding proteins, known as writers, erasers, and readers, respectively. Emerging evidence suggests that m⁶A modification and its regulators are involved in every aspect of normal hematopoietic development, from the emergence of hematopoietic stem cells to the generation of mature blood cells. Also, it has been established that abnormal expression of m⁶A regulators is implicated in the initiation of blood diseases. In this review, we summarize the latest findings regarding the role of m⁶A in erythropoiesis and highlight its implications in the pathophysiology of hemoglobin disorders. Full article

Obesity has emerged as a global health challenge, closely associated with multiple metabolic diseases, such as cardiovascular diseases, type 2 diabetes, and non-alcoholic fatty liver disease. The traditional “calories-in minus calories-out” paradigm is no longer sufficient to explain the heterogeneity of obesity; consequently, a growing body of research has turned its focus to epigenetic regulation—particularly chemical modifications at the RNA level. N⁶-methyladenosine (m⁶A) modification is one of the most abundant epigenetic modifications on RNA, which dynamically regulates the methylation reaction in specific sequences on mRNA through methyltransferases (writers), demethylases (erasers), and binding proteins (readers). Accumulating evidence in recent years has revealed that m⁶A modification plays a pivotal role in the pathogenesis and progression of obesity, particularly through its regulation of key biological processes, such as adipocyte differentiation, lipid metabolism, and energy homeostasis. Given its critical involvement in metabolic dysregulation, targeting m⁶A-related mechanisms may offer novel therapeutic avenues for obesity management. This review systematically summarizes the current understanding of m⁶A modification in obesity, elucidates its underlying molecular mechanisms, and evaluates its potential as a therapeutic target. By integrating recent advances in the field, we aim to provide new perspectives for the development of innovative strategies in obesity treatment. Full article

Resveratrol (RES), a natural polyphenol with lipid metabolism-regulating properties, also demonstrates remarkable efficacy in strengthening intestinal barrier integrity. In order to elucidate the mechanism by which RES ameliorates intestinal damage and lipid metabolism disturbances in Megalobrama amblycephala under a high-fat (HF) diet, a conventional diet (CON), an HF diet (HF), or an HF diet supplemented with 0.6, 3, or 6 g/kg RES (HF + 0.06%, 0.3%, or 0.6% RES) was fed to fish. After 8 weeks, RES supplementation in the HF diet significantly improved the growth performance and alleviated hepatic lipid deposition. Microbiota profiling revealed RES improved intestinal barrier function by reducing α-diversity, Actinobacteria and Bosea abundances, and enriching Firmicutes abundance. RES also maintained the integrity of the intestinal physical barrier and inhibited the inflammatory response. MeRIP-seq analysis indicated that RES modulated intestinal mRNA m⁶A methylation by upregulating methyltransferase-like 3 (mettl3) and downregulating fat mass and obesity-associated gene (fto) and Alk B homolog 5 (alkbh5). Combined RNA-seq and MeRIP-seq data revealed that RES alleviated endoplasmic reticulum stress (ERS) by upregulating the m⁶A methylation and gene level of heat shock protein 70 (hsp70). Correlation analyses identified significant associations between intestinal microbiota composition and ERS, tight junction, and inflammation. In summary, RES ameliorates lipid dysregulation via a synergistic mechanism involving intestinal microbiota, m⁶A modification, ERS, barrier function, and inflammatory response. Full article

RNA modifications regulate diverse aspects of transcripts’ function and stability. Among these, N1-methyladenine (m¹A) is a reversible mark primarily installed by the TRMT6/TRMT61A methyltransferase on tRNA, though it is also found on other RNA types. m¹A has been implicated in protecting mRNAs during acute protein misfolding stress. However, the role of m¹A under chronic proteotoxic conditions, such as intracellular amyloid aggregation, remains poorly understood. To address this gap, we examined the effects of reduced N1-adenine methylation in human cells undergoing amyloidogenesis. Suppression of the methyltransferase TRMT61A or overexpression of the m¹A-specific demethylase ALKBH3 enhanced amyloid aggregation. A deficiency of N1-adenine methylation also impaired the expression of a reporter mRNA-encoded protein, highlighting the protective role of m¹A in safeguarding transcript functionality. Proteomic analysis of amyloid aggregates from TRMT61A-deficient cells revealed increased co-aggregation of bystander proteins, particularly those with known RNA-binding activity. At the same time, the aggregates from methylation-deficient cells contained elevated levels of mRNAs. Collectively, our findings support a role for m¹A in preventing RNA entanglement within aggregates and limiting RNA-mediated propagation of protein co-aggregation. Full article

Glioblastoma multiforme (GBM), the most aggressive primary brain tumor in adults, has a poor prognosis due to rapid recurrence and treatment resistance. This review examines the evolution of radiotherapy (RT) for GBM management, from whole-brain RT to modern techniques like intensity-modulated RT (IMRT) and volumetric modulated arc therapy (VMAT), guided by 2023 European Society for Radiotherapy and Oncology (ESTRO)-European Association of Neuro-Oncology (EANO) and 2025 American Society for Radiation Oncology (ASTRO) recommendations. The standard Stupp protocol (60 Gy/30 fractions with temozolomide [TMZ]) improves overall survival (OS) to 14.6 months, with greater benefits in O6-methylguanine-DNA methyltransferase (MGMT)-methylated tumors (21.7 months). Tumor Treating Fields (TTFields) extend median overall survival (mOS) to 31.6 months in MGMT-methylated patients and 20.9 months overall in supratentorial GBM (EF-14 trial). However, 80–90% of recurrences occur within 2 cm of the irradiated field due to tumor infiltration and radioresistance driven by epidermal growth factor receptor (EGFR) amplification, phosphatase and tensin homolog (PTEN) mutations, cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletions, tumor hypoxia, and tumor stem cells. Pseudoprogression, distinguished using Response Assessment in Neuro-Oncology (RANO) criteria and positron emission tomography (PET), complicates response evaluation. Targeted therapies (e.g., bevacizumab; PARP inhibitors) and immunotherapies (e.g., pembrolizumab; oncolytic viruses), alongside advanced imaging (multiparametric magnetic resonance imaging [MRI], amino acid PET), support personalized RT. Ongoing trials evaluating reirradiation, hypofractionation, stereotactic radiosurgery, neoadjuvant therapies, proton therapy (PT), boron neutron capture therapy (BNCT), and AI-driven planning aim to enhance efficacy for GBM IDH-wildtype, but phase III trials are needed to improve survival and quality of life. Full article

Asthma is a chronic inflammatory airway disease influenced by both genetic and environmental factors. Recent insights have underscored the pivotal role of epigenetic regulation in the pathogenesis and heterogeneity of asthma. This review focuses on key epigenetically important regulators categorized as writers, erasers, and readers that govern DNA methylation, histone modifications, and RNA modifications. These proteins modulate gene expression without altering the underlying DNA sequence, thereby influencing immune responses, airway remodeling, and disease severity. We highlight the structural and functional dynamics of histone acetyltransferases (e.g., p300/CBP), histone deacetylases (e.g., SIRT family), DNA methyltransferases (DNMT1, DNMT3A), demethylases (TET1), and methyl-CpG-binding proteins (MBD2) in shaping chromatin accessibility and transcriptional activity. Additionally, the m6A RNA modification machinery including METTL3, METTL14, FTO, YTHDF1/2, IGF2BP2, and WTAP is explored for its emerging significance in regulating post-transcriptional gene expression during asthma progression. Structural characterizations of these proteins reveal conserved catalytic domains and interaction motifs, mirroring their respective families such as SIRTs, p300/CBP, DNMT1/3A, and YTHDF1/2 critical to their epigenetic functions, offering mechanistic insight into their roles in airway inflammation and immune modulation. By elucidating these pathways, this review provides a framework for the development of epigenetic biomarkers and targeted therapies. Future directions emphasize phenotype-specific epigenomic profiling and structure-guided drug design to enable precision medicine approaches in asthma management. Full article

Background/Objectives: The conventional treatment of glioblastoma (GBM) with alkylating agents is not curative. The protein O6-methylguanine DNA methyltransferase (MGMT) is a significant limitation, being able to repair drug-induced DNA damage. Thus, exploring non-alkylating agents already approved by the FDA is imperative. The antidepressant fluoxetine (FL) has been explored due to its anti-cancer properties. However, its first-pass effect and its non-targeted distribution to brain tissue are major limitations of FL’s administration, which is conventionally orally administered. Thus, the primary objective of this work was the development of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) tailored with folic acid (FA) for FL delivery to GBM cells. Methods: A Central Composite Design (CCD) was applied to optimize the NPs. Results: The developed FA-functionalized PLGA NPs exhibited physicochemical properties suitable for brain-targeted delivery. The final formulation presented an average diameter of 167 ± 8 nm, a polydispersity index (PdI) of 0.23 ± 0.07, and a zeta potential of −22.2 ± 0.3 mV. The encapsulation efficiency (EE) and loading capacity (LC) values were 44.4 ± 3.8% and 3.1 ± 0.3%, respectively. In vitro studies demonstrated that the NPs are stable in storage and simulated physiological conditions and can maintain a controlled and slow-release profile of FL for 17 days. In vitro cell uptake experiments demonstrated that conjugation with FA enhances the NPs’ internalization in GBM cells overexpressing folate receptors through endocytosis mediated by this receptor. Furthermore, in vitro cytotoxicity experiments demonstrated that the FL encapsulation in the developed NPs maintains drug efficacy, as well as it was able to increase cell sensitivity to treatment with an alkylating agent. Conclusions: These results suggest that the developed NPs are effective nanocarriers, either as a standalone therapy or as a chemosensitizer in combination with the standard GBM treatment. Full article

Quaternary ammonium compounds (QACs) are a class of chemicals used for their antimicrobial, surfactant, and antistatic properties. QACs are present in many consumer products, and people are regularly exposed to them. We have previously shown reproductive toxicity in mice exposed to the disinfectants alkyl dimethyl benzyl ammonium chloride (ADBAC) and dodecyl dimethyl ammonium chloride (DDAC). To assess the long-term reproductive impacts, a generational reproductive study was conducted. Sperm parameters were determined by CASA and epigenetic enzyme mRNA expression was determined by pathway-focused RT-PCR. Mice ambiently exposed to ADBAC+DDAC exhibited decreases in reproductive indices that persisted through the F1 generation. Male mice (F0) dosed with 120 mg/kg/day of ADBAC+DDAC exhibited decreased sperm concentration and motility that persisted through the F1 generation. Changes in the mRNA expression of chromatin-modifying enzymes in the testes were seen. Two histone acetyltransferases (Hat1 and Kat2b) were upregulated, and one lysine-specific demethylase (Kdm6b) was downregulated in the F0 generation. The DNA methyltransferase Dnmt1 was downregulated in F1 males. These changes in chromatin-modifying enzymes are known to decrease fertility and could be a mechanism for ADBAC+DDAC reproductive toxicity. In all experiments, the F2 generation was similar to the controls, showing multi-generational but not trans-generational epigenetic inheritance. Full article

The bidirectional relationship between epilepsy and depression illustrates shared neurobiological mechanisms of neuroinflammation, hypothalamic–pituitary–adrenal axis dysregulation, and glutamatergic dysfunction. Depression is present in 20–55% of people with epilepsy, far greater than in the general population, while depression doubles epilepsy risk 2.5-fold, indicating shared pathophysiology. Neuroinflammatory mediators (interleukin-6, tumor necrosis factor alpha, high-mobility group box 1) establish a vicious cycle: seizures exacerbate inflammation and mood disruption, and stress lowers seizure thresholds. Hippocampal damage and cortisol toxicity also link these disorders, with early life stress imprinting lifelong risk via epigenetic alteration. Genetic studies identify pleiotropic genes (brain-derived neurotrophic factor) that regulate synaptic plasticity, serotonin activity, and immune responses. New treatments target shared pathways: ketamine and AMPAkines normalize glutamate tone; mGluR5 antagonists attenuate hyperexcitability and inflammation; DNA methyltransferase inhibitors reverse aberrant DNA methylation; and probiotics manipulate the gut–brain axis by boosting neuroprotective metabolites like butyrate. Despite challenges—transient effects, precision dosing, and blood–brain barrier penetration—these advances constitute a paradigm shift toward mechanistic repair rather than symptom management. The way forward includes clustered regularly interspaced short palindromic repeats (CRISPR)-based epigenome editing, biomarker-led therapies, and combination approaches (e.g., ketamine and probiotics). Such comorbidity needs to be managed holistically through integrated neuropsychiatry care, offering hope to patients with treatment-refractory symptoms. Full article

PR/SET domain 2 (PRDM2)/RIZ is a member of the histone/protein methyltransferases (PRDMs) superfamily. Discovered to have the ability to bind retinoblastoma in the mid-1990s, PRDM2 was assumed to play a role in neuronal development. Like other family members characterized by a conserved N-terminal PR structural domain and a classical C2H2 zinc-finger array at the C-terminus, PRDM2 encodes two major protein types, the RIZ1 and RIZ2 isoforms. The two subtypes differ in the presence or absence of the PR domain: the RIZ1 subtype has the PR domain, whereas the RIZ2 subtype lacks it. The PR domain exhibits varying conservation levels across species and shares structural and functional similarities with the catalytic SET domain, defining histone methyltransferases. Functioning as an SET domain, the PR domain possesses protein-binding interfaces and acts as a lysine methyltransferase. The variable number of classic C2H2 zinc fingers at the C-terminus may mediate protein–protein, protein–RNA, or protein–DNA interactions. An imbalance in the RIZ1/RIZ2 mechanism may be an essential cause of malignant tumors, where PR-positive isoforms are usually lost or downregulated. Conversely, PR-negative isoforms are always present at higher levels in cancer cells. RIZ1 isoforms are also important targets for estradiol interaction with hormone receptors. PRDM2 can regulate gene transcription and expression combined with transcription factors and plays a role in the development of several systemic diseases through mRNA expression deletion, code-shift mutation, chromosomal deletion, and missense mutation occurrence. Thus, PRDM2 is a key indicator for disease diagnosis, but it lacks systematic summaries to serve as a reference for study. Therefore, this paper describes the structure and biological function of PRDM2 from the perspective of its role in various systemic diseases. It also organizes and categorizes its latest research progress to provide a systematic theoretical basis for a more in-depth investigation of the molecular mechanism of PRDM2’s involvement in disease progression and clinical practice. Full article

Background: SET domain-containing 5 (SETD5) is a member of the protein lysine-methyltransferase family. SETD5 gene mutations cause disorders of the epigenetic machinery which determinate phenotypic overlap characterized by several abnormalities. SEDT5 gene variants have been described in patients with KBG and Cornelia de Lange (CdL) syndromes. Case description: A female patient with severe short stature and intellectual disability had been followed since she was 9 years old. Several causes of short stature were ruled out. At the age of 12 years, her height was 114 cm (−5.22 SDS), weight 19 kg (−5.88 SDS), BMI 14.6 kg/m² (−2.26 SDS), and was Tanner stage 1. The target height for the proband was 151.65 cm (−1.80 SDS). The bone age (BA) was delayed by 3 years compared to chronological age. The growth rate was persistently deficient (<<2 SDS). Physical examination revealed dysmorphic features. Genetic analysis documented a de novo SETD5 gene mutation (c.890_891delTT), responsible for phenotypes in the context of an overlap syndrome between the phenotype of MDR23, CdL and KBG syndromes. Recombinant growth hormone therapy (rhGH) was started at the age of 12 years. After both one year (+3.16 SDS) and two years (+2.9 SDS), the growth rate significantly increased compared with the pre-therapy period. Conclusion: This is the first case of a patient with overlap syndrome due to SETD5 mutation treated with rhGH. The review of the scientific literature highlighted the clinical and molecular features of SETD5 gene mutation and the use of rhGH therapy in patients suffering from CdL and KBG syndromes. Full article

Dietary protein levels greatly influence gut microbial ecosystems; however, their effects on gut archaea and associated functions in ruminants require further elucidation. This study evaluated the impact of varying dietary protein levels on gut archaeal composition, antimicrobial resistance (AMR) genes, virulence factors, and functional capacities in sheep. Eighteen ewes (Yunnan semi-fine wool breed, uniparous, 2 years old, and averaging 50 ± 2 kg body weight) were randomly assigned to diets containing an 8.5 (low; H_1), 10.3 (medium; H_m), or 13.9% (high; H_h) crude protein level from the 35th day of pregnancy to the 90th day postpartum. The total duration of the experiment was approximately 202 days. A total of nine fecal samples (three from each group) were analyzed via 16S rRNA and metagenomics sequencing. Higher archaeal alpha diversity and richness were observed in the H_m and H_h groups compared to the H_l group (p < 0.05). A Beta diversity analysis revealed the archaeal community’s distinct clustering mode based on protein levels. The methanogenic genera Methanobrevibacter and Methanocorpusculum were dominant across the three groups, and their abundance was influenced by protein intake. A functional prediction analysis indicated moderate changes in amino acid and carbohydrate metabolism, which are particularly associated with methane production, an important source of greenhouse gases. AMR genes (e.g., tetA (60), patA, vat, and Erm methyltransferase) and virulence factors (Bacillibactin, LPS) were significantly enriched when animals were fed high-protein diets. Our results demonstrated that dietary protein levels significantly influence gut archaeal composition, AMR gene enrichment, and related functional pathways. Medium-protein diets promoted greater archaeal diversity, whereas high-protein diets favored resistance gene proliferation and enhanced methanogenic activity. Optimizing dietary protein intake may enhance gut health, mitigate antimicrobial resistance risk, and reduce methane emissions, thereby supporting livestock sustainability and environmental protection. Full article