Clinical Epigenetics

IntroductionDNA methylation (DNAm) has shown promise as a biological marker of gestational age (GA). Here, we aimed to characterize how plasma circulating miRNAs - another epigenetic mechanism regulating gene expression - associate with GA at birth, and to construct a miRNA-based GA clock (miRClock-GA). MethodsWe leveraged 2083 umbilical cord plasma-derived circulating miRNAs from Generation R (N=1695). First, we performed linear regressions to identify miRNome-wide significant miRNAs associated with GA. Second, we applied elastic net regression to construct miRClock-GA. These steps were validated in Gen3G (N=213). Finally, we computed age acceleration (miRClock-AA) and evaluated association of miRClock-GA and miRClock-AA with child developmental outcomes up to 17 years of age, including comparisons with DNAmClocks. FindingsWe identified 123 miRNAs associated with GA, with miR-150-5p showing the strongest positive association ( B=0.244, SE=0.036, P=2.3e-11) and miR-373-3p the strongest negative association ( B=-0.255, SE=0.065, P=8.6e-5). MiRClock-GA correlated consistently with GA in Generation R train (rrange=0.62-0.72) and test sets (rrange=0.45-0.52) and in the independent validation cohort (rGen3G =0.33). Correlations between miRClock-GA and DNAmClocks were weak to moderate (rrange=0.28-0.42). MiRClock-AA explained significant variance in birthweight and childhood BMI beyond clinical GA. ConclusionsThis study reveals widespread associations between circulating miRNAs and GA, supports miRClock-GA as a consistent, well-performing biological marker of GA, with miRClock-AA predicting birthweight and childhood BMI beyond GA itself. Our findings provide a broader perspective on the potential utility of miRNAs as early markers of development. FundingE.U. Horizon Europe Research and Innovation Programme (FAMILY,No.101057529); European Research Council (TEMPO,No.101039672). Full funding in Acknowledgements. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSEpigenetic clocks have emerged as powerful tools for assessing individual differences in biological ageing. Existing epigenetic clocks are typically constructed using DNA methylation (DNAm) data and are developed to estimate whether an individuals epigenetic age deviates relative to their chronological age. In adults, higher predicted biological epigenetic age than chronological age (accelerated epigenetic ageing) is an established indicator of mortality risk and other age-related morbidities. MicroRNAs are another epigenetic mechanism associated with chronological age and age-related phenotypes across species such as C. elegans, mice, primates and humans. Recently, a plasma-derived, cell-free circulating miRNA clock was developed in a sample of older European adults, with accelerated miRNA age predicting biological age-related conditions such as frailty and multi-system blood biomarkers. However, miRNA-based estimations of biological gestational age at birth have not been previously done and their relationship to child health outcomes are unknown. Added value of this studyTo gain a broader perspective on the role of epigenetic markers in biological gestational age at birth and the potential utility of miRNAs as early markers of (altered) development, we leveraged cord blood plasma circulating miRNA data collected at birth in a large population-based cohort. First, we identified 123 miRNAs associated with gestational age. Second, we used this information to construct a miRNA-based epigenetic clock for gestational age (miRClock-GA) and validated this clock in an independent cohort. MiRClock-GA showed moderate correlations with both gestational age and existing DNAm-based gestational clocks. Third, we found that miRClock-GA correlated cross-sectionally with birthweight, as well as prospectively with several adaptive, behavioural, cognitive, and growth outcomes measured up to age 17y, after taking into account maternal influences such as maternal education level, smoking, pre-pregnancy BMI, and age. Accelerated ageing of miRClock-GA (miRClock-AA) explained variance in birthweight and childhood BMI beyond clinical GA, after accounting for maternal influences. Implications of all available evidenceOur study provides the first large-scale evidence that circulating miRNAs in cord blood plasma show widespread associations with gestational age at birth and can be used to derive a robust biological marker of GA (MiRClock-GA), which explains a substantial proportion of the variation in clinical GA. MiRClock-AA provides information beyond GA in some child outcomes, such as BMI. These findings extend adult research, supporting the potential of miRNAs as promising markers for early risk assessment and health monitoring in a developmental context.

BackgroundHigh grade serous ovarian cancer (HGSC) is initially a responsive tumor to platinum (Pt)-based therapy. Pt resistance in HGSC is associated with epigenetic modifications and hypomethylating agents (HMAs) have been studied as carboplatin resensitizing agents. As DNA methylation is detectable in cancer cells and in blood, here we aimed to develop a blood-based methylation signature associated with cancer and cancer recurrence in HGSC. ResultsWe evaluated genome-wide DNA methylation in de-identified peripheral blood mononuclear cells (PBMCs) from women 1) without cancer (controls, n=20); 2) newly diagnosed HGSC (prior to treatment, Pt-naive, n=60) 3) Pt-resistant recurrent HGSC before and after treatment with the novel HMA/DNA methyltransferase inhibitor (DNMTI) guadecitabine (Pt-resistant, n=30). The Pt-resistant patients were enrolled in NCT02901899 clinical trial testing guadecitabine and the PD-1 inhibitor pembrolizumab. DNA extracted from PBMCs was analyzed by using Infinium MethylationEPIC BeadChips. There were 30,369 differentially methylated loci (DMLs) in Pt-naive patients vs. controls (adj. p < 0.05, {beta} >10%), with most loci being demethylated. Enriched pathways in PBMCs from cancer patients included mechanisms of cancer, neutrophil degranulation, and cancer-related signaling pathways (PI3K/AKT, STAT3, HGF, interleukins). The number of DMLs was greater (880 DMLs; adj. p<0.05, {beta}>10%) in Pt-resistant vs. Pt-naive patients, and top enriched pathways associated with Pt-resistant HGSC included pathways in cancer, metabolic pathways, platelet activation, ABC transporters and signaling pathways (calcium, PI3K/AKT, MAPK, Ras, ErbB, Hippo, Wnt). Massive genomewide hypomethylation 5 days after treatment with guadecitabine was observed (13,742 DMLs; adj. p<0.05, {beta}>10%), which persisted 30 days after discontinuation of treatment. Pathways enriched by hypomethylated genes in PBMCs following guadecitabine treatment interestingly included pathways related to neuronal signaling, such as glutaminergic receptor signaling, axonal guidance signaling, synaptic long-term depression, synaptogenesis signaling and serotonin receptor signaling. Deconvolution analysis of the methylome data of PBMCs from Pt-resistant recurrent HGSC before versus after HMA treatment predicted increased naive B cells, memory and naive CD+ T cells, naive CD4+ T cells, and neutrophils and decreased monocytes. ConclusionsWe propose new DMLs associated with Pt-naive versus Pt-resistant HGSC. These findings can lead to new biomarkers for HGSC.

BackgroundFathers adolescent smoking and overweight affect respiratory health in offspring, suggesting that paternal puberty exposures may influence offspring biological ageing through preconception epigenetic mechanisms. MethodsWe analyzed epigenetic age acceleration using four validated epigenetic clocks derived from blood DNA methylation in 892 RHINESSA offspring (mean age 27 years), linked to parental data on smoking and body shapes from RHINE/ECRHS. Linear regression examined parental smoking initiation ([&le;]15 or >15 years) and overweight body shape (childhood/puberty or age 30) in relation to offspring epigenetic age acceleration, adjusting for offspring sex, age and parental socioeconomic status. Sensitivity analyses accounted for offspring smoking and BMI. ResultsPCHorvath ({beta} 1.53; 95% CI 0.02, 2.9), PCGrimAge (1.21; 0.03, 2.1), DunedinPACE (0.04; -0.001, 0.1) and PCPhenoAge (1.92; -0.3, 4.2) were accelerated in daughters of fathers who started smoking [&le;]15 years. Likewise, PCHorvath (2.25; 1.2, 3.3), PCGrimAge (1.36; -0.2, 2.9), DunedinPACE (0.07; 0.01, 0.1) and PCPhenoAge (3.11; 1.8, 4.4) were accelerated in daughters and sons of fathers who had been overweight in childhood and puberty. These results remained largely unchanged after additional adjustments or stratification in sensitivity analyses. No associations were found for maternal smoking or overweight in puberty. ConclusionsEpigenetic ageing is accelerated in offspring of fathers who smoked or were overweight in puberty, independent of offspring lifestyle. These findings suggest that adolescent boys environment and lifestyle may be critical for next-generation health. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/26352444v1_fig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@1eea189org.highwire.dtl.DTLVardef@1af41f4org.highwire.dtl.DTLVardef@1132932org.highwire.dtl.DTLVardef@f5ba2c_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO Graphical abstract Legend to graphical abstract Figure Fathers smoking or overweight during puberty was associated with accelerated epigenetic aging in offspring (n=892), independent of the offsprings own lifestyle. No such pattern was observed for maternal puberty exposures, or when paternal exposures occurred after puberty. Male puberty may be a critical window for next-generation health. C_FIG

BackgroundAgeing is a sex-specific process characterised by a progressive decline in physiological integrity. DNA methylation represents a primary epigenetic hallmark of ageing, yet sex-specific patterns of epigenetic ageing within and across tissues remain poorly understood. This study aims to address these gaps through an integrated analysis of sex-moderated epigenetic ageing across eight human tissues. MethodsA total of 137 DNA methylation datasets comprising over 36,000 individuals aged 10-114 years were analysed using a meta-analytic workflow to identify age-associated differentially methylated positions (aDMPs) and regions (aDMRs), meta-regression to assess sex moderation, and pathway enrichment analyses to interpret functional relevance. FindingsIndividual tissues displayed distinct age-related methylation trajectories, but some DMP sites showed consistent hyper- or hypomethylation across tissues. Across tissues, we identified 68,630 aDMPs (10%) robustly associated with ageing. Age-associated changes at the regional level were less common, with only 80 robust age-associated aDMRs detected across tissues, representing 0.09% of analysed regions. Sex moderation was observed for only 16 aDMPs (0.002%), indicating that sex effects on age-associated DNA methylation are largely tissue-specific rather than shared across tissues. InterpretationOur findings indicate that age-associated DNA methylation changes predominantly occur at isolated CpG sites rather than extended genomic regions and are strongly dependent on tissue and genomic context. The minimal overlap of sex-moderated methylation signals across tissues suggests that age-related sex differences at the epigenetic level are more likely attributable to tissue- and cell-type-specific variation rather than to broadly conserved epigenetic mechanisms shared across tissues. FundingThis study was funded by an Australian Research Council (ARC) Discovery project (DP200101830). Severine Lamon was funded by an ARC Future Fellowship (FT210100278). Nir Eynon was funded by NHMRC Investigator Grant (APP1194159), and a Hevolution/AFAR New Investigator Award in Aging Biology and Geroscience Research. Mandhri D. Abeysooryia was supported by an Australian Government Research Training Program (RTP) Scholarship. Research in context Evidence before this studyDNA methylation is widely recognised as a central epigenetic hallmark of ageing. Previous research has demonstrated that some age-related methylation changes are conserved across tissues, forming the basis of pan-tissue epigenetic clocks. Most studies to date have primarily examined age effects in isolation. Although biological sex influences ageing trajectories and susceptibility to nearly all age-related diseases, sex-moderated epigenetic ageing has received limited investigation. Specifically, pan-tissue clocks, including GrimAge and PhenoAge, are "sex-aware" but were trained and validated in mixed-sex cohorts, limiting their capacity to disentangle tissue-specific sex effects. Consequently, it remains unclear whether sex-moderated epigenetic ageing signals are shared across tissues or are tissue-specific. Added value of this studyThis study provides a large-scale, comprehensive multi-tissue analysis of sex-moderated epigenetic ageing, integrating 137 DNA methylation datasets across eight human tissues and more than 36,000 male and female individuals spanning the lifespan. Our findings show that while age-associated methylation changes are widespread at the CpG level, sex-moderated effects are rare and largely tissue-specific, with minimal overlap across tissues. Implications of all the available evidenceTogether, the available evidence indicates that epigenetic ageing is predominantly driven by shared, conserved age-related methylation changes, whereas sex differences in epigenetic ageing are modest and context dependent. These sex-related effects are more likely to reflect tissue- and cell-type-specific variation rather than widespread, shared mechanisms. This underscores the need to develop sex-specific epigenetic clocks and to conduct longitudinal cohort and intervention studies to more precisely characterise sex-specific dynamics of epigenetic ageing across tissues.

BackgroundColorectal cancer (CRC) is a molecularly heterogeneous disease shaped by both genetic and epigenetic alterations. Approximately 15% of CRCs display widespread CpG island hypermethylation, known as the CpG Island Methylator Phenotype (CIMP). CIMP-high (CIMP-H) tumours frequently exhibit MLH1 promoter hypermethylation, leading to mismatch repair deficiency (MMRd) and microsatellite instability (MSI). However, DNA methylation patterns associated with MSI, independent of CIMP and MLH1 silencing, and the influence of clinical variables such as anatomical location and patient age on the CRC methylome remain poorly characterised. MethodsWe performed epigenome-wide DNA methylation profiling of 259 primary CRC tissue samples using the Illumina EPICv2 array, comparing differential methylation between MSI and microsatellite stable (MSS) CRC, adjusting for tumour purity, MLH1 promoter methylation, CIMP status, and anatomical location, to account for known confounders. We further evaluated the independent effects of anatomical location and patient age on global methylation patterns. ResultsEpigenome-wide differential methylation between MSS and MSI CRC was dominated by MLH1 promoter hypermethylation. After adjusting for MLH1 hypermethylation and CIMP status, we identified a distinct set of 656 CpG sites associated with MMRd independent of MLH1 silencing. These included hypermethylation at LRP6, GSK3{beta}, and CDK12, implicating altered WNT signalling and transcriptional regulation pathways. Comparison of MSI subgroups revealed the co-occurrence of MLH1 hypermethylation with promoter hypermethylation at TXNRD1. Anatomical location showed a strong independent effect on methylation patterns, while we observed only modest effects of patient age on the CRC methylome after adjustment for confounders. ConclusionsWe identified a distinct methylation profile distinguishing MSS and MSI CRC, including MLH1-independent markers of MMRd, as well as novel differentially methylated loci within MSI subgroups. We further showed that anatomical location has a strong independent impact on the CRC methylome. Together, these findings refine the molecular characterisation of CRC and highlight potential epigenetic markers that could inform patient stratification and precision oncology.

AbstractO_ST_ABSBackgroundC_ST_ABSGlioblastoma (GB) is the most aggressive primary brain tumor, characterized by therapy resistance, attributed to a multitude of epi-genetic changes resulting in phenotypic plasticity with altered cell states. To uncover druggable epigenetic vulnerabilities, we disturbed GB-derived spheres and observed coordinated repression of the aberrantly activated hemopoietic stem-like cell signature, dominated by HOXA genes. This signature has been associated with poor prognosis and resistance to therapy in GB. Here we investigate biological vulnerabilities associated with the deregulated epigenetic landscape in high-HOX GB. MethodsGB-derived spheres (GS) were treated with an inhibitor of Bromodomain and extra-terminal motif proteins (BETi) (JQ1) or transduced with inducible constructs to genetically modulate HOXA10 expression (shRNA for knockdown, ectopic HOXA10). Functional effects were evaluated through proliferation, neurosphere formation, and senescence assays. Epigenomic profiling incorporated RNA-seq, ChIP-seq, ATAC-seq, promoter capture MicroC, and DNA methylation. ResultsBETi-mediated rapid, coordinated downregulation of the HOX-signature, suggested direct transcriptional regulation. Knockdown of HOXA10 alone yielded similar effects, decreasing expression of HOXA genes, reducing proliferation, self-renewal capacity, and triggering senescence. Conversely, ectopic HOXA10 expression was ineffective in reactivating the HOXA cluster, or reverse BETi-mediated biological effects. Integrative epigenomic analysis of high-HOX-GS revealed concerted activation of the HOXA region, with broad domains of H3K27ac/H3K4me3 associated with super-enhancer activity, open chromatin (ATAC) and focal DNA hypomethylation. Architectural changes included altered CTCF interactions and increased promoter-anchored looping. ConclusionThese results position the HOX-signature as a potential therapeutic target and offer a mechanistic rationale for disrupting BET-dependent transcriptional regulation in high-HOX GB. Key pointsO_LIEpigenetic activation of stem cell-related high-HOX signature in GB is associated with a super-enhancer encompassing the HOXA locus. C_LIO_LITargeting this vulnerability by BETi or HOXA10 knockdown results in concerted repression and loss of stemness features. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=74 SRC="FIGDIR/small/727851v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@5bf4b9org.highwire.dtl.DTLVardef@11fa405org.highwire.dtl.DTLVardef@497a2eorg.highwire.dtl.DTLVardef@1f47084_HPS_FORMAT_FIGEXP M_FIG C_FIG Created in BioRender. Chiesi, D. (2026) https://BioRender.com/eknk0ez Importance of studyGlioblastoma (GB) are the most aggressive brain tumors in adults that are difficult to treat, due to their high plasticity resulting invariably to resistance to therapies. Here we report on the identification of epigenetic vulnerabilities that may be leveraged in combination therapies. Disturbing GB-derived stem-like cells with epigenetic drugs, we uncovered that a HOXA gene dominated hematopoietic stem cell-related signature, previously associated with aggressiveness and treatment resistance, can be repressed in a coordinated manner, resulting in loss of stem cell features. Analysis of the underlying epigenetic landscape revealed that the HOXA region was activated in high-HOX glioblastoma through the formation of a super-enhancer. This feature presents a particular vulnerability that may be leveraged by BETi as strategy of a combination therapy.

Background: It is an everyday observation that people of the same chronological age differ with respect to their physical and mental capacity. However, assessing these differences in biological age remains challenging. Methods: Here, we aggregate 89 age-associated variables from the Berlin Aging Study II (BASE-II, n=1,631) to generate MultiAge, a new marker of biological age that summarizes information from ten domains reflecting organ health and global biological age. We then used methylation data obtained from an Illumina MethylationEPIC array and supervised machine learning to translate MultiAge into a DNA methylation signature, MultiAgeEpi (309 CpGs), which was subsequently validated in four independent external validation cohorts (KORA FF4, KORA Age, SHIP-TREND, BiDirect, total n=4,339). MultiAgeEpi results were compared with previously published epigenetic clocks (GrimAge, DunedinPACE, SystemsAge). Results: We report that MultiAgeEpi showed similar, and in several cases, stronger associations with age-associated outcomes such as diabetes, metabolic syndrome, multimorbidity, frailty and mortality (q < 0.05) compared to the other clocks. Conclusions: MultiAge and MultiAgeEpi thus provide a comprehensive assessment of biological age through aggregation of numerous age-associated variables and the use of the high-resolution methylomics data makes transfer of this marker to other cohorts possible.

Background: The biological mechanisms linking generalized anxiety disorder (GAD) and COVID-19 remain poorly understood, despite substantial evidence of their comorbidity. To address this gap, we examined genetic and epigenetic factors underlying their co-occurrence. Methods: In a multi-ancestry sample of 893 participants, we conducted genome-wide and epigenome-wide analyses of GAD and COVID-19 severity. Integrating large-scale genome-wide datasets and information regarding methylation quantitative trait loci, complementary analytic approaches were used to identify regional methylation patterns, assess genetically regulated DNA methylation in blood and brain tissue, and evaluate causal loci shared between GAD and COVID-19. Results: GAD was associated with epigenome-wide significant variation in loci involved in chromatin regulation and synaptic signaling. Conversely, COVID-19-related epigenetic signals were enriched in immune-inflammatory and host-response pathways. Mild COVID-19 was epigenetically related to endothelial-inflammatory signals, while severe COVID-19 was linked to epigenetic changes implicated in myeloid and thrombo-inflammatory pathways. Epigenetic signals shared between GAD and COVID-19 implicated processes related to stress adaptation and tissue homeostasis. Genetically informed analyses identified 60 shared loci, including MAPT, ZFP57, and FBXL18, indicating pleiotropy between GAD and COVID-19 in genetically regulated DNA methylation variation. Brain-specific analyses further highlighted convergence in additional loci (i.e., MICB and HLA-DPB1), suggesting neuroimmune mechanisms underlying GAD-COVID-19 shared methylation patterns. Conclusions: These findings support that GAD and COVID-19 share epigenetic and genetic architecture involving pathways related to vascular integrity, immune function, and cellular adaptation, highlighting a potential neuroimmune basis for their co-occurrence.

BackgroundDNA methylation-based biomarkers have been widely used to predict biological age; however, most blood-derived data have been used in most existing models, and whether cheek mucosa can serve as an alternative indicator for methylation-based estimation of aging-related and clinical phenotypes is unclear. MethodsDNA methylation profiles from cheek mucosa and whole blood of 186 Japanese adults were analyzed using Illumina Infinium Methylation Screening Array (MSA). Models were constructed to predict chronological age, phenotypic age, and clinical laboratory biomarkers from cheek mucosa- and blood-derived methylation data. In addition to applying the ordinary elastic net method, a two-stage residual learning method incorporating existing blood-based epigenetic clocks was applied for more accurate prediction of biological age. Sex-stratified analyses and comparisons of selected CpG features across sexes and tissues were performed. ResultsCheek mucosa-derived MSA methylation data enabled accurate prediction of chronological age (R = 0.965) and phenotypic age (R = 0.964) using the two-stage method. The performance gain achieved by the two-stage approach was greater for phenotypic age than for chronological age. Multiple clinical laboratory biomarkers could be predicted using cheek mucosa-derived methylation data, particularly after sex stratification, including inflammatory, metabolic, thyroid-related, and sex hormone-related markers. Most biomarkers that could be predicted using blood-derived methylation data were also predicted using cheek mucosa-derived methylation data. However, the CpG sites selected for prediction showed minimal overlap across sexes and tissues despite overlap in the corresponding predictable phenotypes. ConclusionsCheek mucosa-derived DNA methylation profiles measured using the MSA can predict chronological age, phenotypic age, and multiple clinically relevant laboratory biomarkers, supporting the utility of cheek mucosa as a less invasive alternative for methylation-based assessment of biological aging and systemic physiological state.

Background Preterm birth (PTB) rates among Hispanic/Latina individuals in the United States have risen over the past decade. Data suggests this rise may be driven in part by psychosocial stress. Leukocyte telomere length (LTL), a marker of cumulative cellular aging that shortens under chronic stress, may capture stress-related biological vulnerability, but has not been examined as a potential population-level contributor to PTB in Hispanic/Latina pregnancies. Objective To examine the association between mid-pregnancy maternal LTL and PTB in a population-based Hispanic/Latina cohort. Methods In a case-control study nested within a California singleton birth cohort (n = 436 Hispanic/Latina individuals; 215 PTB, 221 term births), LTL was measured by quantitative PCR from biobank specimens collected from 15 to 20 weeks of gestation. Covariates from linked birth certificate and hospital discharge records were included. Logistic regression estimated ORs and 95% CIs of PTB by LTL examined continuously and by percentile category (<=10th, 11th-89th, >=90th) with and without adjustment for covariates. Results Mean and median LTL did not differ between PTB and term births. LTL at or below the 10th percentile was associated with elevated odds of PTB relative to full-term birth (12.6% versus 4.3%; ORc = 3.2, 95% CI 1.3-7.9), persisting after partial (ORadj1 = 3.2, 95% CI 1.3-8.3) and full covariate adjustment (ORadj2 = 3.4, 95% CI 1.3-9.3). Subgroup analyses showed consistent directional patterns across PTB subgroups and for early term birth (ORadj2 = 5.1, 95% CI 1.5-17.0). Conclusions Mid-pregnancy maternal LTL <=10th percentile was associated with more than three times the odds of PTB, with risk concentrated at the extreme low tail of the distribution. Consistent with a cumulative allostatic load model, markedly short LTL at mid-gestation may reflect elevated stress-related biological risk for preterm delivery. These findings support upstream investment in stress reduction and prospective LTL research in high-burden populations.

Objective: To characterize genome-wide DNA methylation patterns associated with sepsis using the Infinium Methylation EPIC v2.0 platform and to evaluate the feasibility of pooled methylation profiling in a pilot critical care cohort. Design: Single-center pilot epigenome-wide association study using pooled whole-blood genomic DNA and pool-level bioinformatic analysis. Setting: Academic medical center. Patients: Fifty critically ill adults enrolled within 48 hours of illness onset and 20 healthy controls. Interventions: None. Measurements and Main Results: Critically ill patients required mechanical ventilation and/or vasopressor support. Sepsis was defined according to Sepsis-3 criteria. Seventy individual samples were organized into 14 intended pools of 5 individuals each: 7 sepsis pools, 3 critically ill non-septic pools, and 4 healthy-control pools. One critically ill non-septic pool was excluded because of poor DNA quality, yielding 13 analyzable pools. For the primary pooled comparison, 7 sepsis pools were compared with 6 non-sepsis comparator pools comprising 2 critically ill non-septic and 4 healthy-control pools. After quality control and preprocessing with SeSAMe, 876,094 CpG sites were retained. The initial pool-level screen identified 170,897 candidate differentially methylated regions. Application of stringent secondary filters (false discovery rate <= 1%, absolute delta-beta >= 7.5%, and >= 5 CpGs per region) yielded a high-confidence subset with marked directional skewing, including 155 hypomethylated and 32 hypermethylated regions in sepsis. Differentially methylated region-associated genes were enriched in myeloid leukocyte activation, myeloid leukocyte-mediated immunity, defense response to bacterium, neutrophil granule biology, and hematopoietic cell lineage pathways. Additional signals involved microRNA-associated targets, ribosome biogenesis, RNA processing, long noncoding RNAs, and previously uncharacterized loci. Conclusions: In this pilot pooled EPIC v2.0 study, sepsis was associated with a biologically coherent, predominantly hypomethylated methylation signature enriched in myeloid and host-defense pathways. These findings support the feasibility of pooled methylation profiling for discovery-oriented sepsis biobank studies but should be interpreted as hypothesis-generating given the pool-level design, limited effective sample size, heterogeneous comparator group, and lack of direct validation against individual-level methylation profiles.

IntroductionChronic inflammation has been implicated in lung carcinogenesis. Prospective studies have linked higher circulating C-reactive protein (CRP), an acute-phase inflammation marker, to higher lung cancer risk in predominantly smoking populations but lower risk in never smokers. We evaluated DNA methylation-based inflammation risk scores (DNAm-IRSs), which may capture longer-term immune-inflammatory and exposure-related biology, with lung cancer risk among never smokers. MethodsWe evaluated six DNAm-IRSs, including four CRP-based scores (IRSLigthart, IRSWielscher, IRSLinear_Hillary, IRSElnet_Hillary), in 683 risk-set-sampled case-control pairs nested in the Shanghai Womens Health Study (n=74,941). We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using conditional logistic regression. We examined DNAm-derived leukocyte composition and circulating immune-inflammatory proteins to characterize DNAm-IRS biology. ResultsCirculating CRP correlated positively with IRSLigthart (r=0.19), IRSWielscher (r=0.13), and IRSElnet_Hillary (r=0.30), but inversely with IRSLinear_Hillary (r=-0.02). Per standard deviation increase, IRSLigthart was associated with lower lung cancer risk (HR=0.85, 95% CI: 0.76-0.95), and IRSWielscher with lower risks of lung cancer (HR=0.87, 95% CI: 0.77-0.97) and adenocarcinoma (HR=0.83, 95% CI: 0.71-0.97). Associations persisted after adjustment for leukocyte composition and strengthened after adjustment for DNAm pack-years, an epigenetic smoking index that may capture combustion-related exposures beyond active smoking. Inverse associations were more evident among women with lower DNAm pack-years, although formal interaction tests were not statistically significant. Both scores were positively associated with acute-phase inflammation, IFN-{gamma}/effector trafficking, and higher CD8+ T-cell proportions. ConclusionsAmong never smokers, selected CRP-related DNAm-IRSs were associated with lower lung cancer risk and were linked to immune features consistent with antitumor activity.

BackgroundRetrotransposable elements (RE) comprise approximately 45% of the human genome and are typically repressed by DNA methylation to preserve genomic integrity. In cancer, global DNA hypomethylation can lead to RE derepression, resulting in genomic instability and activation of innate immune pathways through viral mimicry. While individual RE classes have been examined in clear cell renal cell carcinoma (ccRCC), the integrated epigenetic landscape of multiple RE families and their clinical relevance remain incompletely characterized. MethodsWe performed a genome-wide prediction of DNA methylation across three major RE classes (Alu, LINE-1, and LTR elements) using a validated computational framework applied to Illumina methylation array data from two independent ccRCC tumor cohorts. Integrated unsupervised clustering of RE methylation profiles was used to define the epigenetic subtypes. Associations with clinicopathologic variables, tumor immune microenvironment composition (DNA Methylation-derived), hypoxia signaling, innate immune activation, and overall survival were evaluated. Prognostic relevance was assessed using multivariable Cox regression models adjusting for age, sex, AJCC stage or AUA risk group, and immune and angiogenic tumor microenvironment features. Key findings were then externally validated in CPTAC-ccRCC and independently replicated in an institutional Dartmouth Cancer Center (DCC) cohort with matched methylation and RNA-sequencing data. ResultsIntegrated clustering identified three reproducible RE methylation subtypes, Repressed, Transient, and Active. In the discovery cohort, the Active subtype showed significantly worse overall survival than the Repressed subtype, with a graded survival pattern across RE methylation states that persisted after multivariable adjustment. RE hypomethylation was associated with reduced EPAS1 (HIF2A) expression, increased immune infiltration, elevated PD-1 expression, and heightened cGAS-STING and interferon signaling, consistent with an immune-inflamed yet immunosuppressed tumor state. In the external CPTAC validation cohort, RE methylation subtypes recapitulated key molecular features and showed supportive survival trends. In the independent DCC replication cohort, an Active RE state was again associated with poorer survival, lower EPAS1 expression, increased PD-1 expression, greater CD8 T-cell and Treg infiltration, and elevated T-cell exhaustion signatures, supporting the reproducibility of the prognostic and immune-exhausted phenotype across cohorts. ConclusionsWe identified RE methylation subtypes with distinct molecular, immunologic, and prognostic features in ccRCC. External validation in CPTAC and independent replication in DCC support the robustness of this RE methylation framework across large-scale and institutional cohorts. These findings highlight the prognostic potential of RE methylation profiles and support their integration into molecular classification strategies to improve risk stratification in ccRCC.

Non-small cell lung cancer (NSCLC) remains one of the leading causes of cancer-related mortality, partly because it is often diagnosed at advanced stages and frequently develops resistance to platinum-based chemotherapy. We previously showed that MAFG becomes derepressed following miR-7 hypermethylation, promoting platinum resistance in NSCLC and ovarian cancer cell lines. Although MAFG is a well-established regulator of oxidative stress, recent evidence in melanoma and colorectal cancer suggests an additional role as a regulator of methylator phenotypes. However, how MAFG reshapes the lung cancer epigenome remains unknown. Here, we investigated the contribution of MAFG to DNA methylation remodeling by combining CRISPR/Cas9-mediated MAFG deletion with CpG-Methyl-Array profiling, followed by expression (qPCR) and methylation (qMSP) validation in tumor cell lines. Our translational approach integrated aptahistochemistry using MAFG-specific aptamers in 127 NSCLC patients, methylation analysis in 35 fresh-frozen tumors and 40 FFPE samples, and interrogation of TCGA methylation datasets. MAFG loss reduced promoter methylation of LIF and MAFG itself. Importantly, these effects were subtype-specific, with MAFG expression and methylation displaying distinct transcriptional programs in LUAD versus LUSC, and prognostic associations restricted to KRAS-mutated adenocarcinomas. In NSCL in silico and in house cohorts, lower MAFG methylation and higher MAFG protein levels were both associated with worse prognosis. In summary, our findings identify MAFG as a regulator of DNA methylation in NSCLC and support the use of MAFG DNA methylation, or protein levels as clinically relevant prognostic biomarkers, particularly in lung adenocarcinoma.

BackgroundTelomerase reactivation, a hallmark of many cancers, is associated with expression of its catalytic subunit, hTERT. However, the prognostic significance of telomere maintenance mechanisms in pediatric medulloblastoma remains poorly defined. MethodsIn this multi-institutional retrospective study of telomerase expression and hTERT regulation in newly diagnosed children with medulloblastoma, hTERT and MYC expression were assessed by qRT-PCR, normalized to non-neoplastic brain control samples. hTERT promoter methylation was analyzed using quantitative pyrosequencing and Illumina 450k methylation array. Cox proportional-hazard regression analyses evaluated the association of hTERT expression with progression-free survival (PFS) or overall survival (OS). Spearman correlation and Kruskal-Wallis tests correlated hTERT promoter methylation and expression and assessed variations among medulloblastoma subgroups, respectively. ResultsAmong 74 patients with available hTERT expression and outcome data, higher expression was associated with worse OS (HR=1.22, 95% CI: 1.01-1.47, p=0.036) and PFS (HR=1.17, 95% CI: 1.00-1.37, p=0.051) after adjusting for subgroup. Similar results were obtained when adjusting for metastatic status. Group 3 patients had the highest hTERT expression (p=0.001). Pyrosequencing data were available for 61 patients and 450k methylation array data for 292 patients. hTERT promoter was differentially methylated across subgroups with WNT followed by group 3 demonstrating the highest methylation on 450k (p<0.0001), findings that were confirmed by pyrosequencing. hTERT promoter methylation positively correlated with hTERT expression (Spearman correlation=0.42, p=0.02 by 450k and 0.34, p=0.007 by pyrosequencing). No significant correlation was observed between hTERT and MYC expression. ConclusionElevated hTERT expression is associated with worse PFS and OS in medulloblastoma across subgroups, supporting telomerase inhibition as a potential therapeutic strategy.

BackgroundX chromosome inactivation (XCI) is the mechanism which randomly silences one X chromosome to equalise gene expression between 46, XX females and 46, XY males. Though XCI is expected to result in a random pattern of mosaicism across tissues, some females display a significantly unbalanced ratio in immune cells, termed XCI-skew, in which [&ge;]75% of cells have the same X inactivated. XCI-skew is associated with adverse health outcomes and its prevalence increases with age - particularly after midlife - yet the specific risk factors have yet to be identified. The menopausal transition, which is driven by profound shifts in sex hormone levels, has significant impact on chronic disease risk yet the molecular and cellular effects are incompletely understood. We hypothesised that the menopausal transition may impact XCI-skew. MethodsUsing XCI data measured in blood-derived DNA from 1,395 females from the TwinsUK population cohort, along with questionnaires, genetic data, and sex hormone measures, we carried out a cross-sectional study to assess the impact of the menopausal transition and sex hormones on XCI-skew. ResultsWe demonstrate that early menopause (<45yrs) is associated with increased risk of XCI-skew. In subset analyses across those who had a surgically induced or natural menopause, we find the association restricted to those who underwent a surgical menopause. We next identify a low polygenic score (PGS) for testosterone levels is significantly associated with XCI-skew, which we replicate in an independent dataset (n=149), while a PGS for age at natural menopause is not associated. Finally, using longitudinal measures across two time points spanning [~]18 years we show XCI-skew is a stable cellular phenotype that typically increases over time. DiscussionThese data represent the first environmental and genetic risk factors of XCI-skew, both of which implicate endogenous sex hormone levels, particularly testosterone. We propose XCI-skew may have clinical relevance in postmenopausal females.

BackgroundDNA methylation can be profiled using multiple technologies that vary in resolution, coverage and cost. Yet systematic benchmarks across these methods remain scarce. MethodsWe compared six widely used technologies -- Illumina EPIC array, TWIST, Whole-Genome Enzymatic Conversion (WGEC), Reduced Representation Bisulfite Sequencing (RRBS), long-read genome sequencing (LR-GS) with Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT) -- using Genome in a Bottle (GIAB) reference samples and ten samples derived of blood and fibroblast cultures of 5 individuals. We assessed CpG coverage, consistency of differentially methylated cytosine (DMC) detection and genomic annotation, with particular attention to overlapping signals across assays. ResultsDespite major differences in assay design, all technologies consistently identified DMCs enriched in promoter and intronic regions, highlighting these loci as robust hotspots of epigenetic variability. Annotation redundancy strongly influenced initial interpretations, with CpG island-related categories largely disappearing once annotations were collapsed to unique features. Sequencing-based methods (WGEC, TWIST, ONT) achieved the most comprehensive coverage, whereas EPIC arrays reproducibly captured promoter-associated differences despite limited scope. ONT sequencing enabled direct, long-read-based methylation profiling with phasing capability and showed strong concordance with short-read sequencing methods after coverage filtering, but required higher and more uniform coverage to achieve reproducible CpG-level agreement. PacBio methylation profiles showed a coverage-dependent discrepancy, with cross-platform concordance plateauing in GIAB samples despite high mean coverage, indicating residual technology-specific biases beyond simple coverage effects. ConclusionsCross-platform benchmarking yields coherent biological insights when coverage and annotation redundancies are carefully addressed. Practically, EPIC arrays remain valuable for promoter-focused cohort studies, WGEC and TWIST enable genome-wide discovery and ONT provides unique phasing and multimodal potential. This comparative framework can guide method selection and support more robust interpretation of DNA methylation data across diverse platforms.

Stressful life events (SLEs) are associated with increased risk of psychiatric and somatic disease, yet the molecular correlates of stress exposure across time remain incompletely characterised. We conducted a multi-omic analysis in the Finnish Twin Cohort, examining genomic (n = 8,286), epigenomic (n = 387), proteomic (n = 401) and metabolomic (n = 434) data across three exposure windows: recent (within 6 months), proximal (within 5 years) and lifetime. Genome-wide association analysis identified a single significant locus on chromosome 1 (lead SNP rs10158287, p = 9.7 x 10-9), mapping to DAB1/C8B, with immune cell-specific eQTL effects in Th1/Th17 CD4+ T cells and cross-trait links to cardiometabolic risk; common variants explained 33.6% of variance in SLE scores; the DAB1/C8B locus alone accounted for 0.4%, consistent with a highly polygenic architecture. No epigenome-wide significant associations or relationships with epigenetic ageing measures (PCPhenoAge, DunedinPACE, PCGrimAge) were detected. Circulating molecular layers showed temporally structured signatures. Recent SLEs were characterised by coordinated immune-metabolic changes, including five proteins (IL-1{beta}, TIGIT, Nectin-1, Carnosinase-1, Calcyphosin; all decreased) and 16 metabolites predominantly reflecting reduced HDL-related lipids and broader lipid pools, alongside enrichment of the lipoprotein assembly and clearance pathway and lower thyroid and lung proteomic age estimates. Proximal exposure showed no significant single-analyte associations but convergent negative pathway-level signals involving cell-cycle and centrosome-associated processes. Lifetime SLEs were characterised by immune-vascular and tissue-remodelling signatures, including ten proteins (all increased), enrichment of TNF/IL-10 signalling, cellular maintenance and epithelial differentiation pathways, and higher arterial proteomic age. These findings indicate that molecular correlates of stress exposure are temporally contingent rather than uniformly accumulating across the life course, with convergent involvement of adaptive immune regulation alongside metabolic and vascular remodelling.

Atherosclerosis is a systemic vascular process linked to cardiovascular, cognitive and renal outcomes. DNA methylation (DNAm)-based scores of atherosclerosis may capture cumulative biological processes underlying vascular aging. Here, we examined associations of DNAm scores for coronary artery calcification (DNAm-CAC) and carotid plaque (DNAm-cPlaque), derived from a large study of imaging-based subclinical atherosclerosis, with prevalent and incident outcomes in two population-based cohorts of older adults: the Health and Retirement Study (HRS; n = 3,875) and The Irish Longitudinal Study on Ageing (TILDA; n = 487). Higher DNAm scores were associated with adverse cardiometabolic profiles and socioeconomic indicators. In HRS, higher DNAm-CAC was associated with prevalent cardiovascular disease (odds ratio per SD, 1.16; 95% confidence interval (CI), 1.07-1.26), lower cognitive function ({beta} = -0.50, 95% CI -0.68 to -0.32) and lower estimated glomerular filtration rate (eGFR; -1.7 ml min-1 1.73 m-2, 95% CI -2.6 to -0.8) in unadjusted models. After adjustment for demographic and clinical risk factors, DNAm-CAC ({beta} = -0.29, 95% CI -0.46 to -0.13) and DNAm-cPlaque ({beta} = -0.24, 95% CI -0.42 to -0.06) remained associated with lower cognitive function, and DNAm-cPlaque was associated with incident cognitive impairment or dementia (hazard ratio per SD, 1.16; 95% CI, 1.01-1.32). Associations were attenuated after further adjustment for race/ethnicity and socioeconomic indicators. In TILDA, higher DNAm-cPlaque was associated with worse cognitive performance (incidence rate ratio, 1.11; 95% CI, 1.01-1.21), increased risk of incident cardiovascular disease (hazard ratio, 1.18; 95% CI, 1.00-1.42) and lower eGFR, with consistent associations observed for DNAm-CAC. These findings suggest that DNAm-based scores of atherosclerosis capture systemic vascular processes linked to multiple age-related outcomes across populations. Further work is needed to clarify the biological pathways reflected by these scores and their relation to cumulative and socially patterned vascular risk.

BackgroundCDH1 (E-cadherin) is a key epithelial adhesion molecule traditionally associated with tumor suppression and epithelial-mesenchymal transition (EMT). However, its roles across cancers remain incompletely understood, particularly within multilayer regulatory contexts involving genomic, epigenetic, transcriptional, and immune mechanisms. MethodsCDH1 expression, survival associations, EMT-correlated gene profiles (VIM, SNAI1, ZEB1), immune infiltration patterns, immune checkpoint correlations (PDCD1, CD274, CTLA4), promoter methylation, and genomic alterations were assessed across five epithelial cancers, breast invasive carcinoma (BRCA), colon adenocarcinoma (COAD), lung adenocarcinoma (LUAD), ovarian cancer (OV), and stomach adenocarcinoma (STAD). Cross-platform validation was performed using TCGA/GDC datasets, GEPIA2, UALCAN, TIMER, KM Plotter, cBioPortal, and g:Profiler. ResultsCDH1 was overexpressed but showed variable prognostic significance; higher expression predicted better survival in COAD, LUAD and STAD, worse survival in BRCA and had no impact in OV. Classic inverse relationships between CDH1 and VIM or ZEB1 were evident only in STAD, and SNAI1 showed no consistent association. Immune infiltration patterns were tumor-specific, ranging from cytotoxic T-cell dominance in LUAD to macrophage-rich profiles in OV; immune checkpoint correlations were similarly context-dependent. Co-expressed genes were enriched for endomembrane transport rather than adhesion pathways. Promoter methylation patterns varied by cancer, whereas genomic alterations of CDH1 were rare. ConclusionsCDH1 does not function as a universal epithelial or EMT marker across epithelial cancers. Instead, its associations with EMT, immune contexture, methylation, and prognosis are context-dependent, supporting a model of CDH1 as a heterogeneous regulator of epithelial plasticity. These findings challenge single-function interpretations and support cancer-specific CDH1 evaluation in translational research.