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1.
Hypertension ; 74(2): 375-383, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31230546

RESUMO

Hypertensive disorders of pregnancy (HDP) are associated with low birth weight, shorter gestational age, and increased risk of maternal and offspring cardiovascular diseases later in life. The mechanisms involved are poorly understood, but epigenetic regulation of gene expression may play a part. We performed meta-analyses in the Pregnancy and Childhood Epigenetics Consortium to test the association between either maternal HDP (10 cohorts; n=5242 [cases=476]) or preeclampsia (3 cohorts; n=2219 [cases=135]) and epigenome-wide DNA methylation in cord blood using the Illumina HumanMethylation450 BeadChip. In models adjusted for confounders, and with Bonferroni correction, HDP and preeclampsia were associated with DNA methylation at 43 and 26 CpG sites, respectively. HDP was associated with higher methylation at 27 (63%) of the 43 sites, and across all 43 sites, the mean absolute difference in methylation was between 0.6% and 2.6%. Epigenome-wide associations of HDP with offspring DNA methylation were modestly consistent with the equivalent epigenome-wide associations of preeclampsia with offspring DNA methylation (R2=0.26). In longitudinal analyses conducted in 1 study (n=108 HDP cases; 550 controls), there were similar changes in DNA methylation in offspring of those with and without HDP up to adolescence. Pathway analysis suggested that genes located at/near HDP-associated sites may be involved in developmental, embryogenesis, or neurological pathways. HDP is associated with offspring DNA methylation with potential relevance to development.

2.
Clin Chim Acta ; 494: 138-142, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30898509

RESUMO

Haptoglobin (Hp) is a major plasma acute-phase glycoprotein, which binds free haemoglobin to neutralize its toxicity. The HP gene exists as two copy number variants (CNV), Hp1 and HP2, which differ in two ways: serum Hp level and functional differences in Hp protein products. Both mechanisms may underlie the HP CNV's influence on susceptibility and/or outcome in several diseases. A single nucleotide polymorphism rs2000999 has also been associated with serum Hp level. In a meta-analysis of three studies from England, France and Japan, with a combined sample size of 1210 participants, we show that rs2000999's effect on circulating Hp level is independent from that of the HP CNV. The combined use of rs2000999 and the HP CNV can be an important genetic epidemiological tool to discriminate between the two potential mechanisms underlying differences between HP1 and HP2 alleles.


Assuntos
Alelos , Haptoglobinas/análise , Adolescente , Adulto , Análise Química do Sangue , Variações do Número de Cópias de DNA/genética , Feminino , França , Genótipo , Humanos , Japão , Masculino , Epidemiologia Molecular , Polimorfismo de Nucleotídeo Único/genética , Reino Unido
3.
Oral Oncol ; 85: 87-94, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30220325

RESUMO

OBJECTIVES: Head and neck squamous cell carcinoma (HNSCC) is often associated with chronic systemic inflammation (SI). In the present study, we assessed if DNA methylation-derived SI (mdSI) indices: Neutrophil-to-Lymphocyte ratio (mdNLR) and Lymphocyte-to-Monocyte ratio (mdLMR) are associated with the presence of HNSCC and overall survival (OS). MATERIALS AND METHODS: We used two peripheral blood DNA methylation datasets: an HNSCC case-control dataset (n = 183) and an HNSCC survival dataset (n = 407) to estimate mdSI indices. We then performed multivariate regressions to test the association between mdSI indices, HNSCC development and OS. RESULTS: Multivariate logistic regression revealed that elevated mdNLR was associated with increased odds of being an HNSCC case (OR = 3.25, 95% CI = 2.14-5.34, P = 4 × 10-7) while the converse was observed for mdLMR (OR = 0.88, 95% CI = 0.81-0.90, P = 2 × 10-3). In the HNSCC survival dataset, HPV16-E6 seropositive HNSCC cases had an elevated mdLMR (P = 9 × 10-5) and a lower mdNLR (P = 0.003) compared to seronegative patients. Multivariate Cox regression in the HNSCC survival dataset revealed that lower mdLMR (HR = 1.96, 95% CI = 1.30-2.95, P = 0.0013) but not lower mdNLR (HR = 0.68, 95% CI = 0.46-1.00, P = 0.0501) was associated with increased risk of death. CONCLUSION: Our results indicate that mdSI estimated by DNA methylation data is associated with the presence of HNSCC and overall survival. The mdSI indices may be used as a valuable research tool to reliably estimate SI in the absence of cell-based estimates. Rigorous validation of our findings in large prospective studies is warranted in the future.

4.
Int J Epidemiol ; 2018 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-29546377

RESUMO

Background: It has been proposed that maternal folic-acid supplement use may alter the DNA-methylation patterns of the offspring during the in-utero period, which could influence development and later-life health outcomes. Evidence from human studies suggests a role for prenatal folate levels in influencing DNA methylation in early life, but this has not been extended to consider persistent effects into adulthood. Methods: To better elucidate the long-term impact of maternal folic acid in pregnancy on DNA methylation in offspring, we carried out an epigenome-wide association study (EWAS) nested within the Aberdeen Folic Acid Supplementation Trial (AFAST-a trial of two different doses: 0.2 and 5 mg, folic acid vs placebo). Offspring of the AFAST participants were recruited at a mean age of 47 years and saliva samples were profiled on the Illumina Infinium Human Methylation450 array. Both single-site and differentially methylated region analyses were performed. Results: We found an association at cg09112514 (p = 4.03×10-9), a CpG located in the 5' untranslated region of PDGFRA, in the main analysis comparing the intervention arms [low- (0.2 mg) and high-dose (5 mg) folic acid combined (N = 43)] vs placebo (N = 43). Furthermore, a dose-response reduction in methylation at this site was identified in relation to the intervention. In the regional approach, we identified 46 regions of the genome that were differentially methylated in response to the intervention (Sidak p-value <0.05), including HLA-DPB2, HLA-DPB1, PAX8 and VTRNA2-1. Whereas cg09112514 did not replicate in an independent EWAS of maternal plasma folate, there was suggested replication of differential methylation in PAX8. Conclusions: The results of this study suggest that maternal folic-acid supplement use is associated with changes in the DNA methylation of the offspring that persist for many years after exposure in utero. These methylation changes are located in genes implicated in embryonic development, immune response and cellular proliferation. Further work to investigate whether these epigenetic changes translate into detectable phenotypic differences is required.

5.
Clin Epigenetics ; 9: 120, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29093763

RESUMO

Background: Eating disorders (ED) are chronic psychiatric disorders, common amongst women of reproductive age. ED in pregnancy are associated with poor nutrition and abnormal intrauterine growth. Increasing evidence also shows offspring of women with ED have adverse developmental and birth outcomes. We sought to carry out the first study investigating DNA methylation in offspring of women with ED. We compared cord blood DNA methylation in offspring of women with active ED (n = 21), past ED (n = 43) and age- and social class-matched controls (n = 126) as part of the Avon Longitudinal Study of Parents and Children. Results: Offspring of women with both active and past ED had lower whole-genome methylation compared to controls (active ED 49.1% (95% confidence intervals 50.5-47.7%), past ED 49.2% (95% CI 50.7-47.7.0%), controls 52.4% (95% CI 53.0%-51.0%)). Amongst offspring of ED women, those born to women with restrictive-type and purging-type ED had lower methylation levels compared to those of controls. Offspring of women with an active restrictive ED in pregnancy had lower whole-genome methylation compared to offspring of women with past restrictive ED. We observed decreased methylation at the DHCR24 locus in offspring of women with active pregnancy ED (effect size (ES) = - 0.124, p = 6.94 × 10-8) and increased methylation at the LGALS2 locus in offspring of women with past ED (ES = 0.07, p = 3.74 × 10-7) compared to controls. Conclusions: Maternal active and past ED are associated with differences in offspring whole-genome methylation. Our results show altered DNA methylation in loci relevant to metabolism; these might be biomarkers of disrupted metabolic pathways in offspring of ED mothers. Further work is needed to examine potential mechanisms and functional outcomes of the observed methylation patterns.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos/genética , Sangue Fetal/química , Galectina 2/genética , Proteínas do Tecido Nervoso/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Efeitos Tardios da Exposição Pré-Natal/genética , Adulto , Metilação de DNA , Feminino , Estudo de Associação Genômica Ampla , Humanos , Modelos Lineares , Estudos Longitudinais , Masculino , Gravidez , Estudos Prospectivos , Adulto Jovem
6.
Int J Cancer ; 140(1): 50-61, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27632354

RESUMO

DNA methylation changes are associated with cigarette smoking. We used the Illumina Infinium HumanMethylation450 array to determine whether methylation in DNA from pre-diagnostic, peripheral blood samples is associated with lung cancer risk. We used a case-control study nested within the EPIC-Italy cohort and a study within the MCCS cohort as discovery sets (a total of 552 case-control pairs). We validated the top signals in 429 case-control pairs from another 3 studies. We identified six CpGs for which hypomethylation was associated with lung cancer risk: cg05575921 in the AHRR gene (p-valuepooled = 4 × 10-17 ), cg03636183 in the F2RL3 gene (p-valuepooled = 2 × 10 - 13 ), cg21566642 and cg05951221 in 2q37.1 (p-valuepooled = 7 × 10-16 and 1 × 10-11 respectively), cg06126421 in 6p21.33 (p-valuepooled = 2 × 10-15 ) and cg23387569 in 12q14.1 (p-valuepooled = 5 × 10-7 ). For cg05951221 and cg23387569 the strength of association was virtually identical in never and current smokers. For all these CpGs except for cg23387569, the methylation levels were different across smoking categories in controls (p-valuesheterogeneity ≤ 1.8 x10 - 7 ), were lowest for current smokers and increased with time since quitting for former smokers. We observed a gain in discrimination between cases and controls measured by the area under the ROC curve of at least 8% (p-values ≥ 0.003) in former smokers by adding methylation at the 6 CpGs into risk prediction models including smoking status and number of pack-years. Our findings provide convincing evidence that smoking and possibly other factors lead to DNA methylation changes measurable in peripheral blood that may improve prediction of lung cancer risk.


Assuntos
Metilação de DNA , DNA/sangue , Neoplasias Pulmonares/diagnóstico , Fumar/genética , Estudos de Casos e Controles , Detecção Precoce de Câncer , Epigênese Genética , Feminino , Predisposição Genética para Doença , Humanos , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , Masculino , Análise em Microsséries/métodos , Fumar/efeitos adversos
7.
PLoS One ; 11(3): e0149475, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26930047

RESUMO

Cardiovascular disease (including coronary artery disease and myocardial infarction) is one of the leading causes of death in Europe, and is influenced by both environmental and genetic factors. With the recent advances in genomic tools and technologies there is potential to predict and diagnose heart disease using molecular data from analysis of blood cells. We analyzed gene expression data from blood samples taken from normal people (n = 21), non-significant coronary artery disease (n = 93), patients with unstable angina (n = 16), stable coronary artery disease (n = 14) and myocardial infarction (MI; n = 207). We used a feature selection approach to identify a set of gene expression variables which successfully differentiate different cardiovascular diseases. The initial features were discovered by fitting a linear model for each probe set across all arrays of normal individuals and patients with myocardial infarction. Three different feature optimisation algorithms were devised which identified two discriminating sets of genes, one using MI and normal controls (total genes = 6) and another one using MI and unstable angina patients (total genes = 7). In all our classification approaches we used a non-parametric k-nearest neighbour (KNN) classification method (k = 3). The results proved the diagnostic robustness of the final feature sets in discriminating patients with myocardial infarction from healthy controls. Interestingly it also showed efficacy in discriminating myocardial infarction patients from patients with clinical symptoms of cardiac ischemia but no myocardial necrosis or stable coronary artery disease, despite the influence of batch effects and different microarray gene chips and platforms.


Assuntos
Angina Instável/genética , Doença da Artéria Coronariana/genética , Perfilação da Expressão Gênica , Infarto do Miocárdio/genética , Isquemia Miocárdica/genética , Angina Instável/diagnóstico , Doença da Artéria Coronariana/diagnóstico , Feminino , Humanos , Masculino , Infarto do Miocárdio/diagnóstico , Isquemia Miocárdica/diagnóstico
8.
IEEE/ACM Trans Comput Biol Bioinform ; 9(6): 1595-606, 2012 Nov-Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23221082

RESUMO

Bioreductive drugs are a class of hypoxia selective drugs that are designed to eradicate the hypoxic fraction of solid tumors. Their activity depends upon a number of biological and pharmacological factors and we used a mathematical modeling approach to explore the dynamics of tumor growth, infusion, and penetration of the bioreductive drug Tirapazamine (TPZ). An in-silico model is implemented to calculate the tumor mass considering oxygen and glucose as key microenvironmental parameters. The next stage of the model integrated extra cellular matrix (ECM), cell-cell adhesion, and cell movement parameters as growth constraints. The tumor microenvironments strongly influenced tumor morphology and growth rates. Once the growth model was established, a hybrid model was developed to study drug dynamics inside the hypoxic regions of tumors. The model used 10, 50 and 100 \mu {\rm M} as TPZ initial concentrations and determined TPZ pharmacokinetic (PK) (transport) and pharmacodynamics (cytotoxicity) properties inside hypoxic regions of solid tumor. The model results showed that diminished drug transport is a reason for TPZ failure and recommend the optimization of the drug transport properties in the emerging TPZ generations. The modeling approach used in this study is novel and can be a step to explore the behavioral dynamics of TPZ.


Assuntos
Antineoplásicos/farmacocinética , Modelos Biológicos , Neoplasias/metabolismo , Neoplasias/patologia , Animais , Antineoplásicos/farmacologia , Transporte Biológico , Processos de Crescimento Celular/efeitos dos fármacos , Processos de Crescimento Celular/fisiologia , Hipóxia Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Simulação por Computador , Humanos , Neoplasias/tratamento farmacológico , Redes Neurais (Computação) , Tirapazamina , Triazinas/farmacocinética , Triazinas/farmacologia , Microambiente Tumoral/efeitos dos fármacos
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