-
EBioMedicine May 2024This study investigates the associations between air pollution and colorectal cancer (CRC) risk and survival from an epigenomic perspective. (Meta-Analysis)
Meta-Analysis
BACKGROUND
This study investigates the associations between air pollution and colorectal cancer (CRC) risk and survival from an epigenomic perspective.
METHODS
Using a newly developed Air Pollutants Exposure Score (APES), we utilized a prospective cohort study (UK Biobank) to investigate the associations of individual and combined air pollution exposures with CRC incidence and survival, followed by an up-to-date systematic review with meta-analysis to verify the associations. In epigenetic two-sample Mendelian randomization analyses, we examine the associations between genetically predicted DNA methylation related to air pollution and CRC risk. Further genetic colocalization and gene-environment interaction analyses provided different insights to disentangle pathogenic effects of air pollution via epigenetic modification.
FINDINGS
During a median 12.97-year follow-up, 5767 incident CRC cases among 428,632 participants free of baseline CRC and 533 deaths in 2401 patients with CRC were documented in the UK Biobank. A higher APES score was associated with an increased CRC risk (HR, 1.03, 95% CI = 1.01-1.06; P = 0.016) and poorer survival (HR, 1.13, 95% CI = 1.03-1.23; P = 0.010), particularly among participants with insufficient physical activity and ever smokers (P > 0.05). A subsequent meta-analysis of seven observational studies, including UK Biobank data, corroborated the association between PM exposure (per 10 μg/m increment) and elevated CRC risk (RR,1.42, 95% CI = 1.12-1.79; P = 0.004; I = 90.8%). Genetically predicted methylation at PM-related CpG site cg13835894 near TMBIM1/PNKD and cg16235962 near CXCR5, and NO-related cg16947394 near TMEM110 were associated with an increased CRC risk. Gene-environment interaction analysis confirmed the epigenetic modification of aforementioned CpG sites with CRC risk and survival.
INTERPRETATION
Our study suggests the association between air pollution and CRC incidence and survival, underscoring the possible modifying roles of epigenomic factors. Methylation may partly mediate pathogenic effects of air pollution on CRC, with annotation to epigenetic alterations in protein-coding genes TMBIM1/PNKD, CXCR5 and TMEM110.
FUNDING
Xue Li is supported by the Natural Science Fund for Distinguished Young Scholars of Zhejiang Province (LR22H260001), the National Nature Science Foundation of China (No. 82204019) and Healthy Zhejiang One Million People Cohort (K-20230085). ET is supported by a Cancer Research UK Career Development Fellowship (C31250/A22804). MGD is supported by the MRC Human Genetics Unit Centre Grant (U127527198).
Topics: Aged; Female; Humans; Male; Middle Aged; Air Pollutants; Air Pollution; Colorectal Neoplasms; DNA Methylation; Environmental Exposure; Epigenesis, Genetic; Epigenomics; Gene-Environment Interaction; Incidence; Mendelian Randomization Analysis; Prospective Studies; Risk Factors
PubMed: 38631091
DOI: 10.1016/j.ebiom.2024.105126 -
Clinical Epigenetics Sep 2023Undernutrition in pregnant women is an unfavorable environmental condition that can affect the intrauterine development via epigenetic mechanisms and thus have... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Undernutrition in pregnant women is an unfavorable environmental condition that can affect the intrauterine development via epigenetic mechanisms and thus have long-lasting detrimental consequences for the mental health of the offspring later in life. One epigenetic mechanism that has been associated with mental disorders and undernutrition is alterations in DNA methylation. The effect of prenatal undernutrition on the mental health of adult offspring can be analyzed through quasi-experimental studies such as famine studies. The present systematic review and meta-analysis aims to analyze the association between prenatal famine exposure, DNA methylation, and mental disorders in adult offspring. We further investigate whether altered DNA methylation as a result of prenatal famine exposure is prospectively linked to mental disorders.
METHODS
We conducted a systematic search of the databases PubMed and PsycINFO to identify relevant records up to September 2022 on offspring whose mothers experienced famine directly before and/or during pregnancy, examining the impact of prenatal famine exposure on the offspring's DNA methylation and/or mental disorders or symptoms.
RESULTS
The systematic review showed that adults who were prenatally exposed to famine had an increased risk of schizophrenia and depression. Several studies reported an association between prenatal famine exposure and hyper- or hypomethylation of specific genes. The largest number of studies reported differences in DNA methylation of the IGF2 gene. Altered DNA methylation of the DUSP22 gene mediated the association between prenatal famine exposure and schizophrenia in adult offspring. Meta-analysis confirmed the increased risk of schizophrenia following prenatal famine exposure. For DNA methylation, meta-analysis was not suitable due to different microarrays/data processing approaches and/or unavailable data.
CONCLUSION
Prenatal famine exposure is associated with an increased risk of mental disorders and DNA methylation changes. The findings suggest that changes in DNA methylation of genes involved in neuronal, neuroendocrine, and immune processes may be a mechanism that promotes the development of mental disorders such as schizophrenia and depression in adult offspring. Such findings are crucial given that undernutrition has risen worldwide, increasing the risk of famine and thus also of negative effects on mental health.
Topics: Pregnancy; Adult; Female; Humans; DNA Methylation; Famine; Mental Disorders; Vitamins; Malnutrition
PubMed: 37716973
DOI: 10.1186/s13148-023-01557-y -
Journal of Oral Pathology & Medicine :... Feb 2024Aberrant epigenetic modifications significantly develop and progress human malignancies including head and neck squamous cell carcinoma (HNSCC). Taking into account... (Review)
Review
BACKGROUND
Aberrant epigenetic modifications significantly develop and progress human malignancies including head and neck squamous cell carcinoma (HNSCC). Taking into account issues of late diagnosis and poor prognosis associated with HNSCC, this systematic review is designed to provide an up-to-date insight of epigenetic changes in the management of HNSCC.
METHODS
All studies that assessed the diagnostic and prognostic utilities of epigenetic changes (DNA methylation and histone modifications) among patients diagnosed with HNSCC or oral potentially malignant disorders (OPMDs) were considered for inclusion till June 2023. Pre-defined Medical Subject Headings terms were used to search Web of Science, Pubmed, Scopus and Embase Ovid databases.
RESULTS
Twenty-five studies were deemed eligible for inclusion with a total number of 3790 samples (2123 HNSCCs, 334 OPMDs and 1333 as controls). DNA methylation was investigated in 18 studies while the role of histone modifications was assessed in seven studies. The most investigated biomarkers among the studies were H3, DAPK and TIMP3. The diagnostic accuracy of the epigenetic biomarkers in detecting HNSCC was assessed in eight studies where the following biomarkers showed the highest area under the curve values: TIPM3, DCC, DAPK, SEPT9, SHOX9, HOXA9 and TRH. None of the studies assessed the predictability of the epigenetic biomarkers in HNSCC and OPMDs.
CONCLUSION
Although initial promising results were seen using the epigenetic biomarkers in the early detection of HNSCC, the limited number of patients and the absence of well-designed longitudinal studies limit the clinical applicability of the outcomes.
Topics: Humans; Squamous Cell Carcinoma of Head and Neck; Epigenesis, Genetic; Head and Neck Neoplasms; DNA Methylation; Prognosis; Biomarkers, Tumor
PubMed: 38316046
DOI: 10.1111/jop.13513 -
Clinical Epigenetics Aug 2023Screening plays a key role in secondary prevention of cervical cancer. High-risk human papillomavirus (hrHPV) testing, a highly sensitive test but with limited... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Screening plays a key role in secondary prevention of cervical cancer. High-risk human papillomavirus (hrHPV) testing, a highly sensitive test but with limited specificity, has become the gold standard frontline for screening programs. Thus, the importance of effective triage strategies, including DNA methylation markers, has been emphasized. Despite the potential reported in individual studies, methylation markers still require validation before being recommended for clinical practice. This systematic review and meta-analysis aimed to evaluate the performance of DNA methylation-based biomarkers for detecting high-grade intraepithelial lesions (HSIL) in hrHPV-positive women.
METHODS
Hence, PubMed, Scopus, and Cochrane databases were searched for studies that assessed methylation in hrHPV-positive women in cervical scrapes. Histologically confirmed HSIL was used as endpoint and QUADAS-2 tool enabled assessment of study quality. A bivariate random-effect model was employed to pool the estimated sensitivity and specificity as well as positive (PPV) and negative (NPV) predictive values.
RESULTS
Twenty-three studies were included in this meta-analysis, from which cohort and referral population-based studies corresponded to nearly 65%. Most of the women analyzed were Dutch, and CADM1, FAM19A4, MAL, and miR124-2 were the most studied genes. Pooled sensitivity and specificity were 0.68 (CI 95% 0.63-0.72) and 0.75 (CI 95% 0.71-0.80) for cervical intraepithelial neoplasia (CIN) 2+ detection, respectively. For CIN3+ detection, pooled sensitivity and specificity were 0.78 (CI 95% 0.74-0.82) and 0.74 (CI 95% 0.69-0.78), respectively. For pooled prevalence, PPV for CIN2+ and CIN3+ detection were 0.514 and 0.392, respectively. Furthermore, NPV for CIN2+ and CIN3+ detection were 0.857 and 0.938, respectively.
CONCLUSIONS
This meta-analysis confirmed the great potential of DNA methylation-based biomarkers as triage tool for hrHPV-positive women in cervical cancer screening. Standardization and improved validation are, however, required. Nevertheless, these markers might represent an excellent alternative to cytology and genotyping for colposcopy referral of hrHPV-positive women, allowing for more cost-effective screening programs.
Topics: Female; Humans; Pregnancy; Uterine Cervical Neoplasms; DNA Methylation; Early Detection of Cancer; Colposcopy; Triage; Papillomavirus Infections; Referral and Consultation; Papillomaviridae; Cell Adhesion Molecule-1
PubMed: 37533074
DOI: 10.1186/s13148-023-01537-2 -
Psychosomatic Medicine Oct 2023Functional somatic syndromes (FSS) are highly prevalent across all levels of health care. The fact that they are characterized by medically unexplained symptoms, such as...
OBJECTIVE
Functional somatic syndromes (FSS) are highly prevalent across all levels of health care. The fact that they are characterized by medically unexplained symptoms, such as fatigue and pain, raises the important question of their underlying pathophysiology. Psychosocial stress represents a significant factor in the development of FSS and can induce long-term modifications at the epigenetic level. The aim of this review was to systematically review, for the first time, whether individuals with FSS are characterized by specific alterations in DNA methylation.
METHODS
MEDLINE and PsycINFO were searched from the first available date to September 2022. The inclusion criteria were as follows: a) adults fulfilling the research diagnostic criteria for chronic fatigue syndrome, fibromyalgia syndrome, and/or irritable bowel syndrome; b) healthy control group; and c) candidate-gene or genome-wide study of DNA methylation.
RESULTS
Sixteen studies ( N = 957) were included. In candidate-gene studies, specific sites within NR3C1 were identified, which were hypomethylated in individuals with chronic fatigue syndrome compared with healthy controls. In genome-wide studies in chronic fatigue syndrome, a hypomethylated site located to LY86 and hypermethylated sites within HLA-DQB1 were found. In genome-wide studies in fibromyalgia syndrome, differential methylation in sites related to HDAC4 , TMEM44 , KCNQ1 , SLC17A9 , PRKG1 , ALPK3 , TFAP2A , and LY6G5C was found.
CONCLUSIONS
Individuals with chronic fatigue syndrome and fibromyalgia syndrome seem to be characterized by altered DNA methylation of genes regulating cellular signaling and immune functioning. In chronic fatigue syndrome, there is preliminary evidence for these to be implicated in key pathophysiological alterations, such as hypocortisolism and low-grade inflammation, and to contribute to the debilitating symptoms these individuals experience.
PREREGISTRATION
PROSPERO identifier: CRD42022364720.
Topics: Adult; Humans; Fatigue Syndrome, Chronic; Fibromyalgia; DNA Methylation; Genome-Wide Association Study; Irritable Bowel Syndrome
PubMed: 37531610
DOI: 10.1097/PSY.0000000000001237 -
Clinical Epigenetics May 2024DNA methylation influences gene expression and function in the pathophysiology of type 2 diabetes mellitus (T2DM). Mapping of T2DM-associated DNA methylation could aid...
OBJECTIVE
DNA methylation influences gene expression and function in the pathophysiology of type 2 diabetes mellitus (T2DM). Mapping of T2DM-associated DNA methylation could aid early detection and/or therapeutic treatment options for diabetics.
DESIGN
A systematic literature search for associations between T2DM and DNA methylation was performed. Prospero registration ID: CRD42020140436.
METHODS
PubMed and ScienceDirect databases were searched (till October 19, 2023). Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and New Castle Ottawa scale were used for reporting the selection and quality of the studies, respectively.
RESULT
Thirty-two articles were selected. Four of 130 differentially methylated genes in blood, adipose, liver or pancreatic islets (TXNIP, ABCG1, PPARGC1A, PTPRN2) were reported in > 1 study. TXNIP was hypomethylated in diabetic blood across ethnicities. Gene enrichment analysis of the differentially methylated genes highlighted relevant disease pathways (T2DM, type 1 diabetes and adipocytokine signaling). Three prospective studies reported association of methylation in IGFBP2, MSI2, FTO, TXNIP, SREBF1, PHOSPHO1, SOCS3 and ABCG1 in blood at baseline with incident T2DM/hyperglycemia. Sex-specific differential methylation was reported only for HOOK2 in visceral adipose tissue (female diabetics: hypermethylated, male diabetics: hypomethylated). Gene expression was inversely associated with methylation status in 8 studies, in genes including ABCG1 (blood), S100A4 (adipose tissue), PER2 (pancreatic islets), PDGFA (liver) and PPARGC1A (skeletal muscle).
CONCLUSION
This review summarizes available evidence for using DNA methylation patterns to unravel T2DM pathophysiology. Further validation studies in diverse populations will set the stage for utilizing this knowledge for identifying early diagnostic markers and novel druggable pathways.
Topics: Female; Humans; Male; Carrier Proteins; Diabetes Mellitus, Type 2; DNA Methylation; Epigenesis, Genetic
PubMed: 38755631
DOI: 10.1186/s13148-024-01670-6 -
Archives of Gynecology and Obstetrics Feb 2024Polycystic ovary syndrome (PCOS) is an endocrine metabolic disease that affects women of reproductive age and is one of the main causes of anovulatory infertility.... (Review)
Review
PURPOSE
Polycystic ovary syndrome (PCOS) is an endocrine metabolic disease that affects women of reproductive age and is one of the main causes of anovulatory infertility. However, the cause of PCOS is yet fully understood, and genetic factors play an important role in its etiology. In this study, we reviewed the main genes involved in the etiology of PCOS and the influence of DNA methylation, aiming to answer the study´s guiding question: 'What is the influence of DNA methylation on the main genes involved in PCOS?'.
METHODS
We used the MEDLINE database, and inclusion criteria (primary and original articles, written in English, found through our entry terms) and exclusion criteria (literature reviews and articles that used animals to perform the experiments and that focused in other epigenetics mechanism without being DNA methylation) were applied.
RESULTS
Twenty-three scientific articles, from a total of 43 articles read in full, were chosen for this study. Eighteen studies confirmed DNA methylation associated with PCOS.
CONCLUSION
The most relevant genes related to PCOS were INSR, LHCGR, and RAB5B, which may be epigenetically altered in DNA, with the first two genes hypomethylated and the last hypermethylated. The epigenetic changes presented in the genes related to PCOS or their promoters were only at the CpG sites.
Topics: Animals; Female; Humans; DNA Methylation; Polycystic Ovary Syndrome; Epigenesis, Genetic; Reproduction
PubMed: 37119419
DOI: 10.1007/s00404-023-07025-5 -
Artificial Intelligence in Medicine Sep 2023DNA methylation biomarkers have great potential in improving prognostic classification systems for patients with cancer. Machine learning (ML)-based analytic techniques... (Review)
Review
BACKGROUND
DNA methylation biomarkers have great potential in improving prognostic classification systems for patients with cancer. Machine learning (ML)-based analytic techniques might help overcome the challenges of analyzing high-dimensional data in relatively small sample sizes. This systematic review summarizes the current use of ML-based methods in epigenome-wide studies for the identification of DNA methylation signatures associated with cancer prognosis.
METHODS
We searched three electronic databases including PubMed, EMBASE, and Web of Science for articles published until 2 January 2023. ML-based methods and workflows used to identify DNA methylation signatures associated with cancer prognosis were extracted and summarized. Two authors independently assessed the methodological quality of included studies by a seven-item checklist adapted from 'A Tool to Assess Risk of Bias and Applicability of Prediction Model Studies (PROBAST)' and from the 'Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK). Different ML methods and workflows used in included studies were summarized and visualized by a sunburst chart, a bubble chart, and Sankey diagrams, respectively.
RESULTS
Eighty-three studies were included in this review. Three major types of ML-based workflows were identified. 1) unsupervised clustering, 2) supervised feature selection, and 3) deep learning-based feature transformation. For the three workflows, the most frequently used ML techniques were consensus clustering, least absolute shrinkage and selection operator (LASSO), and autoencoder, respectively. The systematic review revealed that the performance of these approaches has not been adequately evaluated yet and that methodological and reporting flaws were common in the identified studies using ML techniques.
CONCLUSIONS
There is great heterogeneity in ML-based methodological strategies used by epigenome-wide studies to identify DNA methylation markers associated with cancer prognosis. In theory, most existing workflows could not handle the high multi-collinearity and potentially non-linearity interactions in epigenome-wide DNA methylation data. Benchmarking studies are needed to compare the relative performance of various approaches for specific cancer types. Adherence to relevant methodological and reporting guidelines are urgently needed.
Topics: Humans; DNA Methylation; Epigenome; Prognosis; Neoplasms; Machine Learning
PubMed: 37673571
DOI: 10.1016/j.artmed.2023.102589 -
Environmental Science & Technology Oct 2023Polycyclic aromatic hydrocarbon (PAH) derivatives constitute a significant class of emerging contaminants that have been ubiquitously detected in diverse environmental... (Review)
Review
Polycyclic aromatic hydrocarbon (PAH) derivatives constitute a significant class of emerging contaminants that have been ubiquitously detected in diverse environmental matrixes, with some even exhibiting higher toxicities than their corresponding parent PAHs. To date, compared with parent PAHs, fewer systematic summaries and reanalyses are available for PAH derivatives with great environmental concerns. This review summarizes the current knowledge on the chemical species, levels, biotransformation patterns, chemical analytical methods, internal exposure routes with representative biomarkers, and toxicity of PAH derivatives, primarily focusing on nitrated PAHs (NPAHs), oxygenated PAHs (OPAHs), halogenated PAHs (XPAHs), and alkylated PAHs (APAHs). A collection of 188 compounds from four categories, 44 NPAHs, 36 OPAHs, 56 APAHs, and 52 XPAHs, has been compiled from 114 studies that documented the environmental presence of PAH derivatives. These compounds exhibited weighted average air concentrations that varied from a lower limit of 0.019 pg/m to a higher threshold of 4060 pg/m. Different analytical methods utilizing comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry (GC × GC-TOF-MS), gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS), comprehensive two-dimensional gas chromatography coupled to quadrupole mass spectrometry (GC × GC-QQQ-MS), and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), that adopted untargeted strategies for the identification of PAH derivatives are also reviewed here. Additionally, an in-depth analysis of biotransformation patterns for each category is provided, including the likelihood of specific biotransformation reaction types. For the toxicity, we primarily summarized key metabolic activation pathways, which could result in the formation of reactive metabolites capable of covalently bonding with DNA and tissue proteins, and potential health outcomes such as carcinogenicity and genotoxicity, oxidative stress, inflammation and immunotoxicity, and developmental toxicity that might be mediated by the aryl hydrocarbon receptor (AhR). Finally, we pinpoint research challenges and emphasize the need for further studies on identifying PAH derivatives, tracking external exposure levels, evaluating internal exposure levels and associated toxicity, clarifying exposure routes, and considering mixture exposure effects. This review aims to provide a broad understanding of PAH derivatives' identification, environmental occurrence, human exposure, biotransformation, and toxicity, offering a valuable reference for guiding future research in this underexplored area.
PubMed: 37703436
DOI: 10.1021/acs.est.3c03170 -
Clinical Epigenetics Jul 2023To systematically evaluate the efficacy and safety of FDA-approved isocitrate dehydrogenase (IDH) inhibitors in the treatment of IDH-mutated acute myeloid leukemia (AML). (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To systematically evaluate the efficacy and safety of FDA-approved isocitrate dehydrogenase (IDH) inhibitors in the treatment of IDH-mutated acute myeloid leukemia (AML).
METHODS
We used R software to conduct a meta-analysis of prospective clinical trials of IDH inhibitors in the treatment of IDH-mutated AML published in PubMed, Embase, Clinical Trials, Cochrane Library and Web of Science from inception to November 15th, 2022.
RESULTS
A total of 1109 IDH-mutated AML patients from 10 articles (11 cohorts) were included in our meta-analysis. The CR rate, ORR rate, 2-year survival (OS) rate and 2-year event-free survival (EFS) rate of newly diagnosed IDH-mutated AML (715 patients) were 47%, 65%, 45% and 29%, respectively. The CR rate, ORR rate, 2-year OS rate, median OS and median EFS of relapsed or refractory (R/R) IDH-mutated AML (394 patients) were 21%, 40%, 15%, 8.21 months and 4.73 months, respectively. Gastrointestinal adverse events were the most frequently occurring all-grade adverse events and hematologic adverse events were the most frequently occurring ≥ grade 3 adverse events.
CONCLUSION
IDH inhibitor is a promising treatment for R/R AML patients with IDH mutations. For patients with newly diagnosed IDH-mutated AML, IDH inhibitors may not be optimal therapeutic agents due to low CR rates. The safety of IDH inhibitors is controllable, but physicians should always pay attention to and manage the differentiation syndrome adverse events caused by IDH inhibitors. The above conclusions need more large samples and high-quality RCTs in the future to verify.
Topics: Humans; Prospective Studies; DNA Methylation; Leukemia, Myeloid, Acute; Enzyme Inhibitors; Mutation
PubMed: 37434249
DOI: 10.1186/s13148-023-01529-2