Melanomas are immunogenic with significant variation of tumor infiltrating lymphocytes (TIL). Primary melanomas are routinely scored by pathologists, for TIL grade, as brisk, nonbrisk, and absent, but TIL grade is not utilized in staging. While brisk TIL grade predicts improved melanoma-specific survival, nonbrisk TIL grade often lacks prognostic significance. A high proportion of primary melanomas from stage II and III patients are scored as nonbrisk TIL grade. Our goal is to quantitatively predict T cell estimates in primary melanoma from DNA methylation data using immunofluorescence CD3 + staining as ground truth. Primary cutaneous melanomas (n = 80), analyzed for multiplex-immunofluorescence (CD3, CD8, S100) and whole-genome DNA methylation, underwent elastic net modeling of the proportion of CD3 + T lymphocytes to build a quantitative prediction model for TILs in primary melanoma called EpiTIL. Melanoma-specific survival (MSS) Kaplan–Meier curves significantly differed by primary melanoma EpiTIL tertiles (p = 0.001). Patients with intermediate or highest tertile EpiTIL scores had higher median probability of MSS than those with lowest tertile scores. EpiTIL added significant prognostic value for MSS beyond age, sex, and stage, analyzed using proportional hazard regression modelling (p = 0.012). EpiTIL survival prediction was validated in two multi-omic studies, TCGA (n = 352) and InterMEL (n = 399). Among TCGA melanomas, the survival curves significantly differed by EpiTIL tertile scores (p = 0.009) and EpiTIL scores added prognostic value to clinical factors (p < 0.002). In the InterMEL case–control study of stage II/III melanoma, patients with 5-year MSS without recurrence (controls) had a significantly higher mean EpiTIL scores than those who died of melanoma within 5 years (cases) (p = 1.5e − 11). Using logistic regression, EpiTIL scores significantly predicted 5-year MSS without recurrence, even after adjusting for age, sex, stage and TIL grade, with OR = 4.7 (p = 2.38e-06) comparing the highest to lowest EpiTIL tertiles. Extending the EpiTIL prediction to the Newell metastatic melanoma cohort, we found immune checkpoint inhibitor responders had a significantly higher mean EpiTIL score than non-responders (p = 0.047). EpiTIL is a DNA methylation-based predictor of T cell proportion that demonstrates potential prognostic value in primary melanoma, particularly for stages II and III. Furthermore, higher EpiTIL scores derived from primary melanomas were positively associated with improved therapeutic responses to immune checkpoint inhibitors in metastatic disease, highlighting its potential to identify patients most likely to benefit from immunotherapy.

Abstract Epigenetic clocks have transformed the study of biological aging in epidemiology and clinical trials. However, the utility of these measures in clinical settings is limited by a lack of population-based norms that clinicians, patients, and researchers can use to understand and communicate how fast an individual is aging relative to same-aged peers. Here, we developed age norms for DunedinPACE, an epigenetic Pace of Aging measure derived from DNA methylation. To do so, we meta-analyzed data from 11 cohorts ( N = 37,855 individuals, ages 17-99 years) to characterize the association between chronological age and DunedinPACE. We investigated sex differences and nonlinearity, confirmed results using longitudinal data, verified that age-normed DunedinPACE scores predict clinical outcomes, and illustrated how norms support the needs of clinical aging research. The age norms reported here will help integrate biomarkers of aging, such as DunedinPACE, into precision public health and medicine.

Phenotypic plasticity is a prominent cancer feature that contributes to metastatic potential and resistance to therapy across multiple cancer types. Cancer cell state transitions have been attributed to transcriptional programs, such as the AP1/TEAD-regulated gene network driving the mesenchymal-like (MES) phenotype. In addition, during dissemination, tumor cells are subjected to variable loads of physical mechanical pressure and constriction across transited tissue, which are thought to impact nuclear molecular crowding. How the interplay between mechanical pressure, global 3D nuclear architecture and transcriptional programs contributes to MES identity and metastatic adaptation remains unclear. Using cutaneous melanoma as a model for early dissemination, we integrate in vitro and in vivo epigenomic profiling with nanoscale imaging of cell lines and patient samples to investigate chromatin organization features underlying the MES phenotype. We find that in MES cells, CTCF is relocated from domain boundaries to regulatory regions of EMT-like genes, leading to reduced insulation, extended topological associated domains (TADs) and increased inter-domain contacts, and de novo formation of chromatin hubs. This conformational rewiring, along with loss of heterochromatin, supports nuclear deformability during invasion and dissemination. Conversely, physical constriction of melanocytic cells induces MES-like chromatin features —including CTCF repositioning and heterochromatin loss— and promotes metastasis in vivo. Similarly, pharmacological inhibition of the heterochromatin mark H3K9me3 triggers MES characteristics and increases invasiveness. These results demonstrate that metastatic competency involves both epigenetic and structural nuclear reprogramming, enabling shifts in gene networks and physical adaptability. Our findings reveal mechanistic links between nuclear architecture and aggressive tumor behavior, identifying potential biomarkers and therapeutic targets to intercept metastatic progression.

INTRODUCTION:We evaluated the efficacy of the addition of the anti-diabetic drug metformin to standard-of-care paclitaxel and carboplatin (PC) in patients with advanced and recurrent endometrial cancer (EC). METHODS:In this phase II/III trial, EC patients with chemotherapy-naïve stage III/IVA (with measurable disease) and stage IVB or recurrent (with or without measurable disease) disease were randomly assigned to PC/metformin (850 mg BID) versus PC/placebo. Metformin or placebo was continued as maintenance therapy after completion of PC until disease progression. The primary endpoint of phase II was progression-free survival (PFS). The primary endpoint of phase III was overall survival (OS). Secondary endpoints were objective response, duration of response, and toxicity. RESULTS:From 3/17/2014 to 12/22/2017, 448 patients were randomized to phase II/III studies, and the data were frozen for interim analysis. The phase II study deemed metformin worthy of further investigation in the phase III study. The interim phase III analysis stopped accrual for futility on 2/1/2018. The addition of metformin to PC had a slightly higher hazard of death compared to the PC regimen (HR = 1.088; 90% CI 0.803 to 1.475), which was sufficient to close the study early. The PFS had (HR = 0.814; 90% CI 0.635 to 1.043). At a median follow-up of 10 months and 121 deaths, median OS was not determined and 28 months, on PC/placebo and PC/metformin, respectively. CONCLUSION:The hazard ratios for PFS and OS endpoints was not sufficiently decreased with the addition of metformin to PC to justify continuing the trial.

To investigate the landscape of the activated kinome in MM, we applied a proteomic approach that interrogates the activation status of more than half of the entire kinome (∼300), termed multiplexed kinase inhibitor bead affinity chromatography coupled with mass spectrometry (MIB/MS) on 45 MM patient (pt) tumors (BRAFV600, n=25; NRASQ61, n=5, NF1 loss-of-function, n=4; Triple wild-type n=11) in conjunction with whole exome sequencing and RNA sequencing (RNAseq). We performed exploratory analyses (Wilcoxon rank sum test for each kinase) on the untreated tumors to identify differentially activated kinases in BRAFV600-mutant MM vs. all others. While no activated kinases were differentially expressed in BRAFV600-mutant MM after adjustment for multiple testing, AKT1, PDGFRA, and MAP3K1 kinases exhibited higher MIB binding (i.e., more activated) in BRAFV600E-mutant pts (unadjusted p-value < 0.05). Spearman’s rank correlation tests between the activated kinase and its gene expression by RNAseq and adjusted for multiple testing did not identify a significant correlation for any kinase, suggesting a complex mechanism of kinase activation other than sole gene expression. K-means clustering analysis to classify melanomas into 4 subtypes using a 6-gene discriminant expression signature showed that BRAFV600-mutant tumors were more frequently classified as melanocytic (9/24, MLANA/MITF/SOX10high, AXLlow). In contrast, triple wild-type tumors were more frequently classified as transitory (5/10, MITF/SOX10/ETV4high, AXLlow). We then performed similar exploratory analyses on the baseline (untreated) tumors from the subset of the 20 BRAFV600E-mutant pts who received D+T as part of a prospective clinical trial (NCT01726738; median follow-up 30.5 months, range 2.0-116.1 months) to identify differentially activated kinases that would predict shorter (<12 months) vs. longer progression-free survival. Again, while no kinases survived multiple comparison testing, the bromodomain protein TRIM28, known to regulate melanoma plasticity, exhibited a more consistent loss of MIB binding in BRAFV600E-mutant pts who progressed shorter than in pts who progressed longer than 12 months on D+T (unadjusted p-value < 0.05). 7 baseline-progression tumor pairs were evaluated for MIB/MS, and 6 were for RNAseq. Although diverse resistance mechanisms were identified, as previously described, we also identified melanoma subtype switch in 4/6 pt tumors and a consistent loss of MIB binding of the non-receptor tyrosine kinase PTK6 in response to D+T, an off-target of D and vemurafenib but not encorafenib. Our in vitro findings revealed that off-target PTK6 inhibition by D could activate beta-catenin signaling and contribute to the development of resistance. Steve P. Angus, Naim U. Rashid, Andrew J. Walther, David L. Corcoran, Steven D. Rhodes, Frances A. Collichio, C. Paige Jones, Mikaela J. Bauer, Joel S. Parker, Noah Sciaky, 1Alisha R. Coffey, Samantha M. Bevill, Brian T. Golitz, v Timothy J. Stulhmiller, Nancy E. Thomas, David W. Ollila, Norman E. Sharpless, Carrie B. Lee, Gary L. Johnson, Stergios J. Moschos. Baseline and adaptive activated kinome profiling identifies PTK6 as a mediator of resistance to vemurafenib and dabrafenib but not encorafenib in BRAFV600-mutant metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2051.

Polygenic indexes (PGIs) - DNA-based predictors of individual phenotypes - have become essential tools across biomedical and social sciences. We introduce Version 2 of the Polygenic Index Repository, which expands phenotype coverage from 47 to 61, increases the number of participating datasets from 11 to 20, and adopts a more consistent and improved methodology for PGI construction. For 16 phenotypes, we leverage summary statistics from an updated GWAS meta-analysis with greater statistical power compared to the original release, thereby improving the PGI's predictive power. To improve power for family-based analyses, we provide imputed parental PGIs in all datasets with first-degree relatives and offer a framework for interpreting results from analyses that control for parental PGIs. We illustrate the utility of parental PGIs using two applications: (1) comparing PGI associations with and without parental PGI controls for all phenotypes in two Repository datasets with family data, and (2) for BMI and diastolic blood pressure, exploring the contribution of causal versus non-causal components of PGI associations to the imperfect portability of PGIs across subgroups within a genetic ancestry. Collectively, the updates enhance predictive performance, broaden the Repository's scope, and introduce novel resources that reduce confounding bias and improve interpretability.

The addition of pembrolizumab to preoperative radiotherapy (RT) improved disease-free survival (DFS) for patients with stage III undifferentiated pleomorphic sarcoma (UPS) and dedifferentiated/pleomorphic liposarcoma (LPS) in the randomized SU2C-SARC032 trial. To precisely identify patients who benefit from pembrolizumab and RT, we performed comprehensive multi-omics profiling of pre- and post-treatment tumor and blood samples, including bulk RNA-seq, flow cytometry, and cytometry by time of flight. Additionally, we built a single-cell RNA-seq atlas spanning 65,786 cells from UPS and LPS to recover single-cell states in bulk tumor samples using digital cytometry. Two opposing tumor microenvironments (TMEs), immune-cold sarcoma ecotype 1 (SE1) and immune-hot sarcoma immune class E (SIC E), benefited from pembrolizumab. Pembrolizumab combined with RT depleted PD-1+ exhausted T cells in SIC E sarcomas and increased effector memory CD4+ T cells in SE1 sarcomas with an overall increase in CD8+ early activated T cells, CD4+ follicular helper T cells, and T cell receptor diversity. Matrix-remodeling stromal and epithelial-like sarcoma cell programs were associated with worse outcomes and diminished with pembrolizumab and RT. Our findings identify different mechanisms of response to pembrolizumab in localized, high-risk UPS/LPS and suggest that sarcoma TME signatures may identify patients most likely to benefit from adding pembrolizumab to preoperative RT.

BACKGROUND:Posttraumatic stress disorder (PTSD) is a mental disorder that may occur in the aftermath of severe psychological trauma. Epigenetic changes in the brain may play a critical role in understanding the neurobiology of PTSD by linking environmental traumatic stress exposure to lasting alterations in gene expression that shape neuronal function. METHODS:We examined 1,065,750 DNA methylation (DNAm) sites from 171 donors including neurotypical controls and PTSD and major depressive disorder (MDD) cases across 6 regions implicated in the fear circuitry of the brain. We performed RNA sequencing (RNA-seq) to examine changes in gene expression and linked these changes to changes in DNAm at nearby sites in a case-control manner. We created a single cell-type atlas of DNAm using a single-nucleus RNA-seq reference panel to map epigenetic changes to specific cell types. Finally, we leveraged a human PTSD ketamine trial to associate blood DNAm biomarkers of ketamine efficacy with specific changes in DNAm in the brain. RESULTS:We found significant differential methylation for PTSD near 195 genes, and to further resolve the changes we observed, we constructed a cell type-specific DNAm atlas defined for changes to the PTSD methylome across 6 cell types. To identify potential therapeutic intersections for PTSD, we found significant methylation levels in the MAD1L1, ELFN1, and WNT5A genes in patients with PTSD who responded to ketamine. Finally, to better understand the unique biology of PTSD, we analyzed matching methylation data for a cohort of donors with MDD with no known history of trauma or PTSD. CONCLUSIONS:Our results implicate DNAm as an epigenetic mechanism underlying the molecular changes associated with the subcortical fear circuitry of the PTSD brain.

Endometrial cancer (EC) is the fourth most common cancer in women in the USA. Stark racial disparities are present in EC outcomes in which Black women have significantly higher EC-related mortality than White women. The social and biologic factors that contribute to these disparities are complex and may include racial differences in epigenetic landscapes. To investigate race-specific epigenetic differences in EC tumor characteristics and outcomes, we utilized the most recent data within the Cancer Genome Atlas (TCGA). Genome-wide CpG methylation data for more than 850 000 CpG sites were analyzed across 245 tumor samples, including 52 from Black women and 181 from White women. Race-adjusted and race-stratified associations among CpG methylation in ECs and molecular subtypes and disease-free survival were examined. Race-specific analysis identified subtype-associated CpGs within 9572 genes in tumors from White women and only 10 genes in tumors that were from Black women. Race-specific analyses also identified survival-associated CpGs with 1119 unique genes identified in tumors from White women and none identified in tumors from Black women. Genes identified with differential methylation among subtypes included those involved in oxidative stress (HIF3A), and DNA repair (MLH1). Data from a replication cohort highlighted genes overlapping with those identified within the TCGA, such as G Protein Subunit Beta 1 (GNB1), involved in G-protein signaling, and Interleukin 37 (IL37), involved in cytokine signaling. Identification of these racial differences in EC tumor epigenetic landscapes and associated changes in gene expression may provide insight into strategies to improve outcomes and reduce disparities.

Ten eleven translocation (TET) proteins are tumor suppressors that through their catalytic activity oxidize 5-methylcytosine to 5-hydroxymethylcytosine, to promote DNA demethylation and to regulate gene expression. Notably, TET2 is one of the most frequently mutated genes in hematological malignancies, including T cell lymphomas. However, murine models with deletion of TET2 do not exhibit T cell expansion, presumably due to redundancy with other members of the TET family of proteins. In order to gain insight on the TET mediated molecular events that safeguard T cells from aberrant proliferation we performed serial adoptive transfers of murine CD4 T cells that lack concomitantly TET2 and TET3 to fully immunocompetent congenic mice. Here we show a progressive acquisition of malignant traits upon loss of TET2 and TET3 that is characterized by loss of genomic integrity, acquisition of aneuploidy and upregulation of the protooncogene Myc.

Transdifferentiation (TD), a somatic cell reprogramming process that eliminates pluripotent intermediates, creates cells that are ideal for personalized anti-cancer therapy. Here, we provide the first evidence that extracellular vesicles (EVs) from TD-derived induced neural stem cells (Exo-iNSCs) are an efficacious treatment strategy for brain cancer. We found that genetically engineered iNSCs generated EVs loaded with the tumoricidal gene product TRAIL at nearly twice the rate of their parental fibroblasts, and TRAIL produced by iNSCs was naturally loaded into the lumen of EVs and arrayed across their outer membrane (Exo-iNSC-TRAIL). Uptake studies in ex vivo organotypic brain slice cultures showed that Exo-iNSC-TRAIL selectively accumulates within tumor foci, and co-culture assays demonstrated that Exo-iNSC-TRAIL killed metastatic and primary brain cancer cells more effectively than free TRAIL. In an orthotopic mouse model of brain cancer, Exo-iNSC-TRAIL reduced breast-to-brain tumor xenografts by approximately 3000-fold compared to treatment with free TRAIL, with all Exo-iNSC-TRAIL treated animals surviving through 90 days post-treatment. In additional in vivo testing against aggressive U87 and invasive GBM8 glioblastoma tumors, Exo-iNSC-TRAIL also induced a statistically significant increase in survival. These studies establish a novel, easily generated, stable, tumor-targeted EV to efficaciously treat multiple forms of brain cancer.

PURPOSE Patients with stage II and III cutaneous primary melanoma vary considerably in their risk of melanoma-related death. We explore the ability of methylation profiling to distinguish primary melanoma methylation classes and their associations with clinicopathologic characteristics and survival. MATERIALS AND METHODS InterMEL is a retrospective case-control study that assembled primary cutaneous melanomas from American Joint Committee on Cancer (AJCC) 8th edition stage II and III patients diagnosed between 1998 and 2015 in the United States and Australia. Cases are patients who died of melanoma within 5 years from original diagnosis. Controls survived longer than 5 years without evidence of melanoma recurrence or relapse. Methylation classes, distinguished by consensus clustering of 850K methylation data, were evaluated for their clinicopathologic characteristics, 5-year survival status, and differentially methylated gene sets. RESULTS Among 422 InterMEL melanomas, consensus clustering revealed three primary melanoma methylation classes (MethylClasses): a CpG island methylator phenotype (CIMP) class, an intermediate methylation (IM) class, and a low methylation (LM) class. CIMP and IM were associated with higher AJCC stage (both P = .002), Breslow thickness (CIMP P = .002; IM P = .006), and mitotic index (both P < .001) compared with LM, while IM had higher N stage than CIMP ( P = .01) and LM ( P = .007). CIMP and IM had a 2-fold higher likelihood of 5-year death from melanoma than LM (CIMP odds ratio [OR], 2.16 [95% CI, 1.18 to 3.96]; IM OR, 2.00 [95% CI, 1.12 to 3.58]) in a multivariable model adjusted for age, sex, log Breslow thickness, ulceration, mitotic index, and N stage. Despite more extensive CpG island hypermethylation in CIMP, CIMP and IM shared similar patterns of differential methylation and gene set enrichment compared with LM. CONCLUSION Melanoma MethylClasses may provide clinical value in predicting 5-year death from melanoma among patients with primary melanoma independent of other clinicopathologic factors.

Biological aging is the correlated decline of multi-organ system integrity central to the etiology of many age-related diseases. A novel epigenetic measure of biological aging, DunedinPACE, is associated with cognitive dysfunction, incident dementia, and mortality. Here, we tested for associations between DunedinPACE and structural MRI phenotypes in three datasets spanning midlife to advanced age: the Dunedin Study (age=45 years), the Framingham Heart Study Offspring Cohort (mean age=63 years), and the Alzheimer’s Disease Neuroimaging Initiative (mean age=75 years). We also tested four additional epigenetic measures of aging: the Horvath clock, the Hannum clock, PhenoAge, and GrimAge. Across all datasets (total N observations=3,380; total N individuals=2,322), faster DunedinPACE was associated with lower total brain volume, lower hippocampal volume, greater burden of white matter microlesions, and thinner cortex. Across all measures, DunedinPACE and GrimAge had the strongest and most consistent associations with brain phenotypes. Our findings suggest that single timepoint measures of multi-organ decline such as DunedinPACE could be useful for gauging nervous system health.

Caloric restriction (CR) slows biological aging and prolongs healthy lifespan in model organisms. Findings from CALERIE-2™ – the first ever randomized, controlled trial of long-term CR in healthy, non-obese humans – broadly supports a similar pattern of effects in humans. To expand our understanding of the molecular pathways and biological processes underpinning CR effects in humans, we generated a series of genomic datasets from stored biospecimens collected from n=218 participants during the trial. These data constitute the first publicly-accessible genomic data resource for a randomized controlled trial of an intervention targeting the biology of aging. Datasets include whole-genome SNP genotypes, and three-timepoint-longitudinal DNA methylation, mRNA, and small RNA datasets generated from blood, skeletal muscle, and adipose tissue samples (total sample n=2327). The CALERIE Genomic Data Resource described in this article is available from the Aging Research Biobank. This multi-tissue, multi-omic, longitudinal data resource has great potential to advance translational geroscience.

Radiotherapy (RT) for prostate cancer has been associated with an increased risk for the development of bladder cancer. We aimed to integrate clinical and genomic data to better understand the development of RT-associated bladder cancer. A retrospective analysis was performed to identify control patients (CTRL; n = 41) and patients with RT-associated bladder cancer (n = 41). RT- and CTRL-specific features were then identified through integration and analysis of the genomic sequencing data and clinical variables. RT-associated bladder tumors were significantly enriched for alterations in KDM6A and ATM, whereas CTRL tumors were enriched for CDKN2A mutation. Globally, there were an increased number of variants within RT tumors, albeit at a lower variant allele frequency. Mutational signature analysis revealed three predominate motif patterns, with similarity to SBS2/13 (APOBEC3A), SBS5 (ERCC2/smoking), and SBS6/15 (MMR). Poor prognostic factors in the RT cohort include a short tumor latency, smoking status, the presence of the smoking and X-ray therapy mutational signatures, and CDKN2A copy number loss. Based on the clinical and genomic findings, we suggest at least two potential pathways leading to RT-associated bladder cancer: The first occurs in the setting of field cancerization related to smoking or preexisting genetic alterations and leads to the development of more aggressive bladder tumors, and the second involves RT initiating the oncogenic process in otherwise healthy urothelium, leading to a longer latency and less aggressive disease. SIGNIFICANCE:Clinicogenomic analysis of radiation-associated bladder cancer uncovered mutational signatures that, in addition to a short tumor latency, smoking, and CDKN2A loss, are associated with a poor outcome. These clinical and genomic features provide a potential method to identify patients with prostate cancer who are at an increased risk for the development of aggressive bladder cancer following prostate RT.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a sequelae of acute pulmonary embolism (PE) in which the PE remodels into a chronic scar in the pulmonary arteries. This results in vascular obstruction, small vessel arteriopathy and pulmonary hypertension. Our current understanding of CTEPH pathobiology is primarily derived from cell-based studies limited by the use of specific cell markers or phenotypic modulation in cell culture. Here we used single cell RNA sequencing (scRNAseq) of tissue removed at the time of pulmonary thromboendarterectomy (PTE) surgery to identify the multiple cell types, including macrophages, T cells, and smooth muscle cells, that comprise CTEPH thrombus. Notably, multiple macrophage subclusters were identified but broadly split into two categories, with the larger group characterized by an upregulation of inflammatory signaling predicted to promote pulmonary vascular remodeling. Both CD4+ and CD8+ T cells were identified and likely contribute to chronic inflammation in CTEPH. Smooth muscle cells were a heterogeneous population, with a cluster of myofibroblasts that express markers of fibrosis and are predicted to arise from other smooth muscle cell clusters based on pseudotime analysis. Additionally, cultured endothelial, smooth muscle and myofibroblast cells isolated from CTEPH thrombus have distinct phenotypes from control cells with regards to angiogenic potential and rates of proliferation and apoptosis. Lastly, our analysis identified protease-activated receptor 1 (PAR1) as a potential therapeutic target that links thrombosis to chronic PE in CTEPH, with PAR1 inhibition decreasing smooth muscle cell and myofibroblast proliferation and migration. These findings suggest a model for CTEPH similar to atherosclerosis, with chronic inflammation promoted by macrophages and T cells driving vascular remodeling through smooth muscle cell modulation, and suggest new approaches for pharmacologically targeting this disease.

The epigenome of stem cells occupies a critical interface between genes and environment, serving to regulate expression through modification by intrinsic and extrinsic factors. We hypothesized that aging and obesity, which represent major risk factors for a variety of diseases, synergistically modify the epigenome of adult adipose stem cells (ASCs). Using integrated RNA- and targeted bisulfite-sequencing in murine ASCs from lean and obese mice at 5- and 12-months of age, we identified global DNA hypomethylation with either aging or obesity, and a synergistic effect of aging combined with obesity. The transcriptome of ASCs in lean mice was relatively stable to the effects of age, but this was not true in obese mice. Functional pathway analyses identified a subset of genes with critical roles in progenitors and in diseases of obesity and aging. Specifically, Mapt, Nr3c2, App, and Ctnnb1 emerged as potential hypomethylated upstream regulators in both aging and obesity (AL vs. YL and AO vs. YO), and App, Ctnnb1, Hipk2, Id2, and Tp53 exhibited additional effects of aging in obese animals. Furthermore, Foxo3 and Ccnd1 were potential hypermethylated upstream regulators of healthy aging (AL vs. YL), and of the effects of obesity in young animals (YO vs. YL), suggesting that these factors could play a role in accelerated aging with obesity. Finally, we identified candidate driver genes that appeared recurrently in all analyses and comparisons undertaken. Further mechanistic studies are needed to validate the roles of these genes capable of priming ASCs for dysfunction in aging- and obesity-associated pathologies.

BackgroundThe field of epigenomics holds great promise in understanding and treating disease with advances in machine learning (ML) and artificial intelligence being vitally important in this pursuit. Increasingly, research now utilises DNA methylation measures at cytosine-guanine dinucleotides (CpG) to detect disease and estimate biological traits such as aging. Given the challenge of high dimensionality of DNA methylation data, feature-selection techniques are commonly employed to reduce dimensionality and identify the most important subset of features. In this study, our aim was to test and compare a range of feature-selection methods and ML algorithms in the development of a novel DNA methylation-based telomere length (TL) estimator. We utilised both nested cross-validation and two independent test sets for the comparisons.ResultsWe found that principal component analysis in advance of elastic net regression led to the overall best performing estimator when evaluated using a nested cross-validation analysis and two independent test cohorts. This approach achieved a correlation between estimated and actual TL of 0.295 (83.4% CI [0.201, 0.384]) on the EXTEND test data set. Contrastingly, the baseline model of elastic net regression with no prior feature reduction stage performed less well in general-suggesting a prior feature-selection stage may have important utility. A previously developed TL estimator, DNAmTL, achieved a correlation of 0.216 (83.4% CI [0.118, 0.310]) on the EXTEND data. Additionally, we observed that different DNA methylation-based TL estimators, which have few common CpGs, are associated with many of the same biological entities.ConclusionsThe variance in performance across tested approaches shows that estimators are sensitive to data set heterogeneity and the development of an optimal DNA methylation-based estimator should benefit from the robust methodological approach used in this study. Moreover, our methodology which utilises a range of feature-selection approaches and ML algorithms could be applied to other biological markers and disease phenotypes, to examine their relationship with DNA methylation and predictive value.

Abstract A challenge in cancer research is developing reproducible, reliable, and practical models which can capture the complexity of cancer development and treatment. The development of functional precision medicine platforms is emerging as a promising strategy for improving pre-clinical drug testing and guiding clinical decisions. We have developed an organotypic brain slice culture (OBSC) technology composed of intact multicellular tissue which can be rapidly used for spatiotemporal drug response testing. OBSCs are reproducibly generated from Sprague-Dawley rat pups and used as living tissue substrates to culture treat different tumor cell lines and uncultured patient brain tumor resection tissue. We evaluated OBSC quality and reproducibility throughout the study by using a propidium iodide nuclear permeability assay. This technique enabled a broad dynamic range to distinguish between healthy and unhealthy slices. In these studies, the rat pup age at the time of generation had an impact on OBSC quality and quantity, indicating that OBSCs should be generated from eight-day-old pups. We also found that optimal OBSCs were generated using improved methods for brain dissection and OBSC culture conditions, establishing our robust, standardized procedure for OBSC generation. Following this optimization period, we continued to conduct quality control analysis with 6 OBSCs per batch for reproducibility. We also conducted immunohistochemistry analysis immediately after slicing and concluded that morphology of neurons in OBSCs remained unchanged between day 0 and 4. In addition, the activation of astrocytes attenuates by day 4 but persists in macrophages/microglia, suggesting that the myeloid cells can phagocytose dead cells and debris in OBSCs. In summary, these results indicate that the OBSC platform may be an effective model that accelerates preclinical drug testing and directs drug development towards clinical evaluation.

ABSTRACT Post-traumatic stress disorder is a mental disorder that may occur in the aftermath of severe psychological trauma. We examined 1,065,750 DNA methylation (DNAm) sites from 171 donors including neurotypicals, PTSD, and major depressive disorder cases across six areas implicated in the fear circuitry of the brain. We found significant differential methylation for PTSD near 195 genes and utilizing cross-region modeling, identified 6,641 candidate genes. Approximately 26% of differentially methylated CpGs were present near risk loci for PTSD. To identify potential therapeutic intersections for PTSD, we found significant methylation changes in the MAD1L1, ELFN1 , and WNT5A genes in ketamine responders. Finally, to better understand the unique biology of PTSD, we analyzed matching methylation data for a cohort of MDD donors with no known history of trauma or PTSD. Our results implicate DNAm as an epigenetic mechanism underlying the molecular changes associated with the subcortical fear circuitry of the PTSD brain.