Search Results (345)

Bladder cancer pathogenesis is closely linked to epigenetic alterations, particularly DNA methylation and demethylation processes. Environmental carcinogens and persistent inflammatory stimuli—such as recurrent urinary tract infections—can induce aberrant DNA methylation, altering gene expression profiles and contributing to malignant transformation. This review synthesizes current evidence on the role of DNA methyltransferases (DNMT1, DNMT3a, DNMT3b) and the hypermethylation of key tumour suppressor genes, including A2BP1, NPTX2, SOX11, PENK, NKX6-2, DBC1, MYO3A, and CA10, in bladder cancer. It also evaluates the therapeutic application of DNA-demethylating agents such as 5-azacytidine and highlights the impact of chronic inflammation on epigenetic regulation. Promoter hypermethylation of tumour suppressor genes leads to transcriptional silencing and unchecked cell proliferation. Urine-based DNA methylation assays provide a sensitive and specific method for non-invasive early detection, with single-target approaches offering high diagnostic precision. Animal models are increasingly employed to validate these findings, allowing the study of methylation dynamics and gene–environment interactions in vivo. DNA methylation represents a key epigenetic mechanism in bladder cancer, with significant diagnostic, prognostic, and therapeutic implications. Integration of human and experimental data supports the use of methylation-based biomarkers for early detection and targeted treatment, paving the way for personalized approaches in bladder cancer management. Full article

The ataxia–telangiectasia-mutated (ATM) protein plays a crucial role in the DNA damage response, particularly in the homologous recombination (HR) pathway. This study aimed to assess the impact of deleterious ATM variants on homologous recombination deficiency (HRD) and response to PARP inhibitors (PARPi) in melanoma patients, using a cell line established from melanoma tissue of a patient carrying the c.5979_5983del germline ATM variant. Despite proven loss of heterozygosity, lack of ATM activation, and HRD, our model did not show sensitivity to PARPi. We assessed the potential contribution of the Schlafen family member 11 (SLFN11) helicase, whose expression is inversely correlated with PARPi sensitivity in other cancers, to the observed resistance. The ATM mutant cell line lacked SLFN11 expression and featured hypermethylation-mediated silencing of the SLFN11 promoter. While sensitive to the ATR inhibitor (ATRi), the addition of ATRi to PARPi was unable to overcome the resistance. Our findings suggest that ATM mutational status and HRD alone do not adequately account for variations in sensitivity to PARPi in our model. A comprehensive approach is essential for optimizing the exploitation of DNA repair defects and ultimately improving clinical outcomes for melanoma patients. Full article

Bone metastasis remains a significant cause of morbidity and diminished quality of life in patients with advanced breast, prostate, and lung cancers. Emerging research highlights the pivotal role of reversible epigenetic alterations, including DNA methylation, histone modifications, chromatin remodeling complex dysregulation, and non-coding RNA networks, in orchestrating each phase of skeletal colonization. Site-specific promoter hypermethylation of tumor suppressor genes such as HIN-1 and RASSF1A, alongside global DNA hypomethylation that activates metastasis-associated genes, contributes to cancer cell plasticity and facilitates epithelial-to-mesenchymal transition (EMT). Key histone modifiers, including KLF5, EZH2, and the demethylases KDM4/6, regulate osteoclastogenic signaling pathways and the transition between metastatic dormancy and reactivation. Simultaneously, SWI/SNF chromatin remodelers such as BRG1 and BRM reconfigure enhancer–promoter interactions that promote bone tropism. Non-coding RNAs, including miRNAs, lncRNAs, and circRNAs (e.g., miR-34a, NORAD, circIKBKB), circulate via exosomes to modulate the RANKL/OPG axis, thereby conditioning the bone microenvironment and fostering the formation of a pre-metastatic niche. These mechanistic insights have accelerated the development of epigenetic therapies. DNA methyltransferase inhibitors (e.g., decitabine, guadecitabine) have shown promise in attenuating osteoclast differentiation, while histone deacetylase inhibitors display context-dependent effects on tumor progression and bone remodeling. Inhibitors targeting EZH2, BET proteins, and KDM1A are now advancing through early-phase clinical trials, often in combination with bisphosphonates or immune checkpoint inhibitors. Moreover, novel approaches such as CRISPR/dCas9-based epigenome editing and RNA-targeted therapies offer locus-specific reprogramming potential. Together, these advances position epigenetic modulation as a promising axis in precision oncology aimed at interrupting the pathological crosstalk between tumor cells and the bone microenvironment. This review synthesizes current mechanistic understanding, evaluates the therapeutic landscape, and outlines the translational challenges ahead in leveraging epigenetic science to prevent and treat bone metastases. Full article

Background: Parkinson’s disease (PD) involves progressive dopaminergic neuron degeneration and motor deficits. Oligodendrocyte dysfunction contributes to PD pathogenesis through impaired myelination. Methods: Single-nucleus RNA sequencing (snRNA-seq) of PD mice revealed compromised oligodendrocyte differentiation and STAT5B downregulation. Pseudotemporal trajectory analysis via Monocle2 demonstrated impaired oligodendrocyte maturation in PD oligodendrocytes, correlating with reduced myelin-related gene expression (Sox10, Plp1, Mbp, Mog, Mag, Mobp). DoRothEA-predicted regulon activity identified STAT5B as a key transcriptional regulator. Results: Oligodendrocyte-specific STAT5B activation improved myelin integrity, as validated by Luxol Fast Blue staining and transmission electron microscopy; attenuated dopaminergic neuron loss; and improved motor function. Mechanistically, STAT5B binds the MBP promoter to drive transcription, a finding confirmed by the luciferase assay, while the DNMT3A-mediated hypermethylation of the STAT5B promoter epigenetically silences its expression, as verified by MethylTarget sequencing and methylation-specific PCR. Conclusions: DNMT3A inhibited the expression of STAT5B by affecting its methylation, which reduced the transcription of MBP, caused oligodendrocyte myelin damage, and eventually led to dopamine neuron damage and motor dysfunction in an MPTP-induced mouse model. This DNMT3A-STAT5B-MBP axis underlies PD-associated myelin damage, connecting epigenetic dysregulation with oligodendrocyte dysfunction and subsequent PD pathogenesis. Full article

Background/Objectives: This study investigated variations in DNA methylation patterns associated with chronic pain and propensity for recurrent pressure injuries (PrI) in persons with spinal cord injury (SCI). Methods: Whole blood was collected from 81 individuals with SCI. DNA methylation was quantified using Illumina genome-wide arrays (EPIC and EPICv2). Comprehensive clinical profiles collected included secondary health complications, in particular current PrI and chronic pain. Relationships between recurrent PrI and chronic pain and whether the co-occurrence of both traits was mediated by changes in DNA methylation were investigated using R packages limma, DMRcate and mCSEA. Results: Three differentially methylated positions (DMPs) (cg09867095, cg26559694, cg24890286) and one region in the micro-imprinted locus for BLCAP/NNAT are associated with chronic pain in persons with SCI. The study cohort was stratified by PrI status to identify any sites associated with chronic pain and while the same three sites and region were replicated in the group with no recurrent PrI, two novel, hypermethylated (cg21756558, cg26217441) sites and one region in the protein-coding gene FDFT1 were identified in the group with recurrent PrI. Gene enrichment and genes associated with specific promoters using MetaScape identified several shared disorders and ontology terms between independent phenotypes of pain and recurrent PrI and interactive sub-groups. Conclusions: DMR analysis using mCSEA identified several shared genes, promoter-associated regions and CGI associated with overall pain and PrI history, as well as sub-groups based on recurrent PrI history. These findings suggest that a much larger gene regulatory network is associated with each phenotype. These findings require further validation. Full article

Abiotic stress can reprogram the gametophytic pathway; the mechanisms by which floral bud pre-treatment influences microspore embryogenesis initiation remain unclear. In this study, we use bisulfite sequencing, sRNA-seq, and RNA-seq to analyze the dynamic changes in rice microspores under different cold treatment durations. Our results showed that a 10-day cold treatment is essential for CXJ microspore embryogenesis initiation. DNA methylation levels showed a slight change at CG, CHG, and CHH sites under cold treatment. The number of both hyper- and hypomethylated DMRs increased over cold treatment, with more hypermethylated DMRs at 5 and 10 dpt. Hypermethylated DMRs were more frequently in the TSS region compared to hypomethylated DMRs. The proportion of 24 nt sRNAs increased upon cold stress, with more downregulated than upregulated sRNAs at 10 dpt. The number of DMR target DEGs increased from 5 to 10 dpt. Promoter hypomethylation at the CHH site was more frequently associated with DEGs. These outcomes suggested that the RdDM pathway participates in the initiation of rice ME. GO analysis indicated that DMR target DEGs at 10 dpt were enriched in responses to chemical stimuli, biological processes, and stress responses. An auxin-related gene, OsHOX28, was further identified. Its upregulation, potentially mediated by the RdDM pathway, may play a crucial role in the initiation of rice ME. This study provides more information on epigenetic mechanisms during rice ME. Full article

Post-viral conditions, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long COVID (LC), share > 95% of their symptoms, but the connection between disturbances in their underlying molecular biology is unclear. This study investigates DNA methylation patterns in peripheral blood mononuclear cells (PBMC) from patients with ME/CFS, LC, and healthy controls (HC). Reduced Representation Bisulphite Sequencing (RRBS) was applied to the DNA of age- and sex-matched cohorts: ME/CFS (n = 5), LC (n = 5), and HC (n = 5). The global DNA methylomes of the three cohorts were similar and spread equally across all chromosomes, except the sex chromosomes, but there were distinct minor changes in the exons of the disease cohorts towards more hypermethylation. A principal component analysis (PCA) analysing significant methylation changes (p < 0.05) separated the ME/CFS, LC, and HC cohorts into three distinct clusters. Analysis with a limit of >10% methylation difference and at p < 0.05 identified 214 Differentially Methylated Fragments (DMF) in ME/CFS, and 429 in LC compared to HC. Of these, 118 DMFs were common to both cohorts. Those in promoters and exons were mainly hypermethylated, with a minority hypomethylated. There were rarer examples with either no change in methylation in ME/CFS but a change in LC, or a methylation change in ME/CFS but in the opposite direction in LC. The differential methylation in a number of fragments was significantly greater in the LC cohort than in the ME/CFS cohort. Our data reveal a generally shared epigenetic makeup between ME/CFS and LC but with specific, distinct changes. Differences between the two cohorts likely reflect the stage of the disease from onset (LC 1 year vs. ME/CFS 12 years), but specific changes imposed by the SARS-CoV-2 virus in the case of the LC patients cannot be discounted. These findings provide a foundation for further studies with larger cohorts at the same disease stage and for functional analyses to establish clinical relevance. Full article

Mitochondria are dynamic in nature and depending on the energy demand they fuse and divide. This fusion-fission process is impaired in diabetic retinopathy and the promoter DNA of Mfn2, a fusion gene, is hypermethylated and its expression is downregulated. Long noncoding RNAs (RNAs with >200 nucleotides that do not encode proteins) can regulate gene expression by interacting with DNA, RNA, and proteins. Several LncRNAs are aberrantly expressed in diabetes, and among them, MALAT1 is upregulated in the retina, altering the expression of the genes associated with inflammation. Our aim was to investigate MALAT1’s role in mitochondrial dynamics in diabetic retinopathy. Using MALAT1-siRNA-transfected human retinal endothelial cells (HRECs) and human retinal Muller cells (RMCs) incubated in 20 mM D-glucose, Mfn2 expression and activity and its promoter DNA methylation were quantified. Mitochondrial integrity was evaluated by analyzing their fragmentation, ultrastructure, membrane potential, and oxygen consumption rate. Compared to normal glucose, high glucose upregulated MALAT1 expression and downregulated Mfn2 expression and activity in both HRECs and RMCs. MALAT1-siRNA ameliorated the glucose-induced increase in Mfn2 promoter DNA hypermethylation and its activity. MALAT1-siRNA also protected against mitochondrial fragmentation, structural damage, and reductions in the oxygen consumption rate. In conclusion, the upregulation of MALAT1 in diabetes facilitates Mfn2 promoter DNA hypermethylation in retinal vascular and nonvascular cells, leading to its suppression and the accumulation of the fragmented/damaged mitochondria. Thus, the regulation of MALAT1 has the potential to protect mitochondria and provide a possible new target to inhibit/prevent the blinding disease in diabetic patients. Full article

Background: Endometrial cancer (EC) remains a major gynecologic malignancy with limited biomarkers for risk stratification. While killer cell lectin-like receptor G2 (KLRG2) exhibits oncogenic properties in other cancers, its clinical significance and mechanistic roles in EC are unknown. This study aims to systematically characterize KLRG2 expression in EC, evaluate its prognostic significance, decipher underlying molecular mechanisms, and explore its role in tumor immune microenvironment regulation. Methods: We performed integrated multi-omics analyses using TCGA-UCEC (n = 552), GTEx, and GEO cohorts (GSE106191), complemented by qPCR validation (14 EC vs. 14 normal samples). Prognostic models were constructed via Cox regression and time-dependent ROC analysis. Epigenetic regulation was assessed through methylation profiling (UALCAN/MethSurv), and immune correlations were evaluated using TIMER/ESTIMATE algorithms. Results: KLRG2 was significantly overexpressed in EC tissues compared to normal endometrium (p < 0.001), validated by immunohistochemistry and qPCR. High KLRG2 expression independently predicted worse overall survival (HR = 3.08, 95% CI = 1.92–4.96) and progression-free interval (HR = 1.98, 95% CI = 1.37–2.87). Furthermore, elevated KLRG2 levels were significantly associated with advanced-stage disease (p < 0.001), deep myometrial invasion (p < 0.05), and high-grade histology (p < 0.001). Mechanistically, promoter hypomethylation was associated with KLRG2 overexpression (p < 0.001), while hypermethylation at three CpG sites (cg04915254, cg04520485, cg23104233) correlated with poor prognosis. Functional enrichment linked KLRG2 to cell cycle checkpoints and G Protein-Coupled Receptor signaling. Immune profiling revealed cytotoxic lymphocyte depletion (CD8+ T cells: Spearman’s ρ = −0.247, p < 0.001; NK CD56bright cells: Spearman’s ρ = −0.276, p < 0.001) and Th2 polarization (Spearman’s ρ = 0.117, p = 0.006). Conclusions: This comprehensive EC study establishes KLRG2 as a dual diagnostic/prognostic biomarker and immunomodulatory target. These findings provide a rationale for developing KLRG2-directed therapies to counteract tumor-intrinsic proliferation and microenvironmental immune suppression. Future single-cell analyses are warranted to dissect KLRG2-mediated tumor-immune crosstalk. Full article

The tumor suppressor p16^INK4a, encoded by CDKN2A, is frequently inactivated in cancer through genetic or epigenetic mechanisms. While promoter hypermethylation is the most common epigenetic cause, aberrant methylation of CDKN2A exon 2 has also been associated with various tumor types. However, analyzing DNA methylation of exon 2 is challenging due to its high sequence similarity with CDKN2B. We developed a pyrosequencing assay to analyze CpGs in CDKN2A exon 2, which was previously found to be hypermethylated in breast cancer. Our novel primer set enabled co-amplification of the homologous regions in CDKN2A, including CpGs 1–24, and CDKN2B CpGs 1–23. By quantifying the proportion of CDKN2A, we could accurately determine methylation levels for CpGs in CDKN2A exon 2. This method was applied to patient-derived glioma cells and commercial breast cancer cell lines. To reveal the role of exon 2 methylation in gene regulation, we additionally examined CDKN2A^INK4a promoter methylation and expression at both mRNA and protein levels in breast cancer cell lines. We observed a range of (epi)genetic alterations, including homozygous deletions, transcript-specific expression, and exon 2 skipping. Our findings indicate that both promoter and exon 2 methylation contribute to regulation of CDKN2A expression. This novel method provides a valuable tool for future studies seeking a deeper understanding of CDKN2A regulation in cancer. Full article

Aberrant DNA methylation is a hallmark of colorectal cancer (CRC), contributing to tumor progression through the silencing of tumor suppressor genes and activation of oncogenes. Indicaxanthin (IND), a dietary betalain pigment from Opuntia ficus indica, has shown antiproliferative effects in CRC models, yet its epigenetic impact remains unexplored. In this study, we investigated the effects of IND on the methylome of Caco-2 cells using Reduced Representation Bisulfite Sequencing (RRBS). IND induced a global hypermethylation profile, particularly at gene promoters and CpG islands. Among the differentially methylated genes, 60% were protein-coding, and 10% encoded transcription factors, including PAX5 and TFAP4, both hypermethylated at active enhancers. Functional enrichment analysis revealed pathways beyond canonical intestinal functions, suggesting altered cell identity and plasticity. Transcription factor targets (SOX10, NFKB1, AHR, ARNT) were significantly enriched among the affected genes, several of which are involved in transdifferentiation processes. Methylation changes also indicated potential reprogramming toward epithelial cell types from pulmonary or neuroectodermal origin. Moreover, IND induced selective hypomethylation of Alu elements on chromosome 21 and hypermethylation of rDNA loci, hinting at suppressed ribosomal biogenesis. Overall, these findings highlight the epigenetic remodeling potential of IND and its possible role in modulating cell fate and metabolism in CRC cells. Full article

Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor with a dismal prognosis despite advances in multimodal treatment. Conventional therapies fail to achieve durable responses due to GBM’s molecular heterogeneity and capacity to evade therapeutic pressures. Epigenetic alterations have emerged as critical contributors to GBM pathobiology, including aberrant DNA methylation, histone modifications, and non-coding RNA (ncRNA) dysregulation. These mechanisms drive oncogenesis, therapy resistance, and immune evasion. This scoping review evaluates the current state of knowledge on epigenetic modifications in GBM, synthesizing findings from original articles and preclinical and clinical trials published over the last decade. Particular attention is given to MGMT promoter hypermethylation status as a biomarker for temozolomide (TMZ) sensitivity, histone deacetylation and methylation as modulators of chromatin structure, and microRNAs as regulators of pathways such as apoptosis and angiogenesis. Therapeutically, epigenetic drugs, like DNA methyltransferase inhibitors (DNMTis) and histone deacetylase inhibitors (HDACis), appear as promising approaches in preclinical models and early trials. Emerging RNA-based therapies targeting dysregulated ncRNAs represent a novel approach to reprogram the tumor epigenome. Combination therapies, pairing epigenetic agents with immune checkpoint inhibitors or chemotherapy, are explored for their potential to enhance treatment response. Despite these advancements, challenges such as tumor heterogeneity, the blood–brain barrier (BBB), and off-target effects remain significant. Future directions emphasize integrative omics approaches to identify patient-specific targets and refine therapies. This article thus highlights the potential of epigenetics in reshaping GBM treatment paradigms. Full article

Background/Objectives: The methylation of the hypermethylated oncological region (THOR) of human telomerase reverse transcriptase (hTERT) may forecast tumour aggressiveness. This pilot study aimed to evaluate THOR methylation as a potential biomarker for recurrence/malignant transformation in salivary gland pleomorphic adenomas (PA). Methods: THOR methylation was assessed by quantitative pyrosequencing in 96 parotid tissue samples (benign and malignant), including non-neoplastic parotid tissue, PA, recurrent PA (rPA), and carcinomas, along with their adjacent tissues. TERT promoter mutations (TPMs) were analysed by Sanger sequencing. Results: THOR methylation significantly differed across the seven groups. Malignant tissues showed higher THOR methylation than non-neoplastic tissues, whereas benign tumours showed no significant difference from non-neoplastic tissue. THOR methylation in rPA was closer to carcinoma than to normal tissue, similar in rPA and tissues adjacent to rPA, and higher in tissues adjacent to carcinomas than in non-neoplastic tissues. A subset of PA-adjacent tissues showed epigenetic alterations, suggesting an increased risk of recurrence or malignant transformation (5–15%). No TPMs were detected. Conclusions: THOR methylation may add information to differentiate normal from carcinogenic tissues and, as such, may be included in a biomarkers panel. Epigenetic alterations in PA-adjacent tissues with normal histology highlight the need for improved diagnostic markers. Full article

DNA methylation changes, especially hypermethylation of SOX1 and HOXA9, may serve as biomarkers for diagnosis and prognosis in non-small cell lung carcinoma (NSCLC). This study analyzed the methylation status of SOX1 and HOXA9 in 63 primary NSCLC tumor samples, corresponding normal lung tissues, and circulating blood, using bisulfite pyrosequencing. The relationship between methylation patterns and clinicopathologic features was also explored. SOX1 and HOXA9 promoter methylation levels were significantly higher in tumor tissues compared to normal lung tissues and blood samples. Histological subtypes influenced methylation patterns, with squamous cell carcinomas (SCC) showing higher hypermethylation rates at both loci compared to other NSCLC subtypes. HOXA9 hypermethylation was associated with advanced tumor stage (stages II and III). Gender and smoking status did not correlate with methylation status. These findings highlight the cancer-specific nature of SOX1 and HOXA9 hypermethylation in NSCLC. Further investigation into demographic and molecular factors influencing methylation could enhance the clinical utility of SOX1 and HOXA9 in NSCLC diagnosis and management. Full article

Melatonin (MT) has been found to mitigate cadmium (Cd) toxicity with negligible environmental risks. It remains poorly understood as to how MT mitigates Cd-induced growth repression and regulates RNA m⁶A methylation. We aimed to elucidate the effect of MT on growth repression and RNA m⁶A methylation in Arabidopsis (Arabidopsis thaliana) exposed to Cd stress. MT mitigated, on average, 13.96% and 8.42% of growth repression resulting from Cd and mismatch repair (MMR) deficiency. The ameliorative effect on Cd stress was reduced by 70.56% and 34.23% in msh2 and msh6 mutants, respectively. With distinct dose–effect relationships, m⁶A hypermethylation responded to Cd stress rather than Cu stress, which was further elevated in MMR-deficient seedlings. MT reduced m⁶A levels by 22.98% even without stress induction, whereas the depressed m⁶A levels in MMR-deficient seedlings, greatly exceeding those in the WT. The “writer” and “eraser” gene expression responsible for m⁶A methylation was reduced with the concentration of stresses due to MT, but VIR and ALKBH9B no longer responded to Cd stress in msh2 and msh6. Despite the remarkable repression, MMR gene expression was regularly promoted by MT under Cd and Cu stress. Our study provides novel insights into the molecular mechanisms underlying the restorative effects of MT on growth repression and m⁶A methylation regulation, which shed light on Cd phytoremediation. Full article