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1.
Epigenetics ; 14(5): 477-493, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30931802

RESUMO

Involvement of sex hormones in colorectal cancer (CRC) development has been linked to oestrogen receptor ß (ERß). Expression of ERß is found reduced in tumour tissue and inversely related to mortality. However, mechanisms are not well understood. Our study aimed to detect differentially methylated genes associated with ERß expression, which could point to mechanisms by which ERß could influence risk and prognosis of CRC. Epigenome-wide DNA methylation profiling was performed using Illumina HumanMethylation450k BeadChip arrays in two independent tumour sample sets of CRC patients recruited in 2003-2010 by the German DACHS study (discovery cohort n = 917, replication cohort n = 907). ERß expression was measured using immunohistochemistry and scored as negative, moderate and high. Differentially methylated CpG sites and genomic regions were determined using limma in the R-package RnBeads. For the comparison of tumours with moderate/high ERß versus negative expression, differentially methylated CpG sites were identified but not confirmed by replication. Comparing tumours of high with tumours of negative ERß expression revealed 2,904 differentially methylated CpG sites of which 403 were replicated (FDR adjusted p-value<0.05). Replicated CpGs were annotated to genes such as CD36, HK1 or LRP5. A survival analysis indicates that 30 of the replicated CpGs are also associated with overall survival (FDR-adjusted p-value<0.05). The regional analysis identified 60 differentially methylated promotor regions. The epigenome-wide analysis identified both novel genes as well as genes already implicated in CRC. Follow-up mechanistic studies to better understand the regulatory role of ERß could inform potential targets for improving treatment or prevention of CRC.

2.
Leuk Lymphoma ; 60(7): 1803-1811, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30633655

RESUMO

Genetic variants in genes acting during the maturation process of immature B-cell to differentiated plasma cell could influence the risk of developing multiple myeloma (MM). During B-cell maturation, several programmed genetic rearrangements occur to increase the variation of the immunoglobulin chains. Class switch recombination (CSR) is one of the most important among these mechanisms. Germline polymorphisms altering even subtly this process could play a role in the etiology and outcome of MM. We performed an association study of 30 genetic variants in the key CSR genes, using 2632 MM patients and 2848 controls from the International Multiple Myeloma rESEarch (IMMEnSE) consortium, the Heidelberg MM Group and the ESTHER cohort. We found an association between LIG4-rs1555902 and decreased MM risk, which approached statistical significance, as well as significant associations between AICDA-rs3794318 and better outcome. Our results add to our knowledge on the genetic component of MM risk and survival.

3.
Nat Genet ; 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30510241

RESUMO

To further dissect the genetic architecture of colorectal cancer (CRC), we performed whole-genome sequencing of 1,439 cases and 720 controls, imputed discovered sequence variants and Haplotype Reference Consortium panel variants into genome-wide association study data, and tested for association in 34,869 cases and 29,051 controls. Findings were followed up in an additional 23,262 cases and 38,296 controls. We discovered a strongly protective 0.3% frequency variant signal at CHD1. In a combined meta-analysis of 125,478 individuals, we identified 40 new independent signals at P < 5 × 10-8, bringing the number of known independent signals for CRC to ~100. New signals implicate lower-frequency variants, Krüppel-like factors, Hedgehog signaling, Hippo-YAP signaling, long noncoding RNAs and somatic drivers, and support a role for immune function. Heritability analyses suggest that CRC risk is highly polygenic, and larger, more comprehensive studies enabling rare variant analysis will improve understanding of biology underlying this risk and influence personalized screening strategies and drug development.

4.
Int J Epidemiol ; 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30476131

RESUMO

Background: Chronic inflammation is a risk factor for colorectal cancer (CRC). Circulating C-reactive protein (CRP) is also moderately associated with CRC risk. However, observational studies are susceptible to unmeasured confounding or reverse causality. Using genetic risk variants as instrumental variables, we investigated the causal relationship between genetically elevated CRP concentration and CRC risk, using a Mendelian randomization approach. Methods: Individual-level data from 30 480 CRC cases and 22 844 controls from 33 participating studies in three international consortia were used: the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), the Colorectal Transdisciplinary Study (CORECT) and the Colon Cancer Family Registry (CCFR). As instrumental variables, we included 19 single nucleotide polymorphisms (SNPs) previously associated with CRP concentration. The SNP-CRC associations were estimated using a logistic regression model adjusted for age, sex, principal components and genotyping phases. An inverse-variance weighted method was applied to estimate the causal effect of CRP on CRC risk. Results: Among the 19 CRP-associated SNPs, rs1260326 and rs6734238 were significantly associated with CRC risk (P = 7.5 × 10-4, and P = 0.003, respectively). A genetically predicted one-unit increase in the log-transformed CRP concentrations (mg/l) was not associated with increased risk of CRC [odds ratio (OR) = 1.04; 95% confidence interval (CI): 0.97, 1.12; P = 0.256). No evidence of association was observed in subgroup analyses stratified by other risk factors. Conclusions: In spite of adequate statistical power to detect moderate association, we found genetically elevated CRP concentration was not associated with increased risk of CRC among individuals of European ancestry. Our findings suggested that circulating CRP is unlikely to be a causal factor in CRC development.

5.
Cancer Med ; 7(10): 5057-5065, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30191681

RESUMO

Genetic associations between variants on chromosome 5p13 and 8q24 and gastric cancer (GC) have been previously reported in the Asian population. We aimed to replicate these findings and to characterize the associations at the genome and transcriptome level. We performed a fine-mapping association study in 1926 GC patients and 2012 controls of European descent using high dense SNP marker sets on both chromosomal regions. Next, we performed expression quantitative trait locus (eQTL) analyses using gastric transcriptome data from 143 individuals focusing on the GC associated variants. On chromosome 5p13 the strongest association was observed at rs6872282 (P = 2.53 × 10-04 ) and on chromosome 8q24 at rs2585176 (P = 1.09 × 10-09 ). On chromosome 5p13 we found cis-eQTL effects with an upregulation of PTGER4 expression in GC risk allele carrier (P = 9.27 × 10-11 ). On chromosome 8q24 we observed cis-eQTL effects with an upregulation of PSCA expression in GC risk allele carrier (P = 2.17 × 10-47 ). In addition, we found trans-eQTL effects for the same variants on 8q24 with a downregulation of MBOAT7 expression in GC risk allele carrier (P = 3.11 × 10-09 ). In summary, we confirmed and refined the previously reported GC associations at both chromosomal regions. Our data point to shared etiological factors between Asians and Europeans. Furthermore, our data imply an upregulated expression of PTGER4 and PSCA as well as a downregulated expression of MBOAT7 in gastric tissue as risk-conferring GC pathomechanisms.

6.
J Natl Cancer Inst ; 2018 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-29917119

RESUMO

Background: Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10-8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. Methods: We conducted a GWAS in European descent CRC cases and control subjects using a discovery-replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10-8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. Results: The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10-8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. Conclusions: This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screening.

7.
Cancer Med ; 2018 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-29845757

RESUMO

Folate-mediated one-carbon metabolism (FOCM) is a key pathway essential for nucleotide synthesis, DNA methylation, and repair. This pathway is a critical target for 5-fluorouracil (5-FU), which is predominantly used for colorectal cancer (CRC) treatment. A comprehensive assessment of polymorphisms in FOCM-related genes and their association with prognosis has not yet been performed. Within 1,739 CRC cases aged ≥30 years diagnosed from 2003 to 2007 (DACHS study), we investigated 397 single nucleotide polymorphisms (SNPs) and 50 candidates in 48 FOCM-related genes for associations with overall- (OS) and disease-free survival (DFS) using multiple Cox regression (adjusted for age, sex, stage, grade, BMI, and alcohol). We investigated effect modification by 5-FU-based chemotherapy and assessed pathway-specific effects. Correction for multiple testing was performed using false discovery rates (FDR). After a median follow-up time of 5.0 years, 585 patients were deceased. For one candidate SNP in MTHFR and two in TYMS, we observed significant inverse associations with OS (MTHFR: rs1801133, C677T: HRhet  = 0.81, 95% CI: 0.67-0.97; TYMS: rs1001761: HRhet  = 0.82, 95% CI: 0.68-0.99 and rs2847149: HRhet  = 0.82, 95% CI: 0.68-0.99). After FDR correction, one polymorphism in paraoxonase 1 (PON1; rs3917538) was significantly associated with OS (HRhet  = 1.28, 95% CI: 1.07-1.53; HRhzv  = 2.02, 95% CI:1.46-2.80; HRlogAdd  = 1.31, pFDR  = 0.01). Adjusted pathway analyses showed significant associations for pyrimidine biosynthesis (P = 0.04) and fluorouracil drug metabolism (P < 0.01) with significant gene-chemotherapy interactions, including PON1 rs3917538. This study supports the concept that FOCM-related genes could be associated with CRC survival and may modify effects of 5-FU-based chemotherapy in genes in pyrimidine and fluorouracil metabolism, which are relevant targets for therapeutic response and prognosis in CRC. These results require confirmation in additional clinical studies.

8.
Br J Cancer ; 118(12): 1639-1647, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29795306

RESUMO

BACKGROUND: Substantial evidence supports an association between use of menopausal hormone therapy and decreased colorectal cancer (CRC) risk, indicating a role of exogenous sex hormones in CRC development. However, findings on endogenous oestrogen exposure and CRC are inconsistent. METHODS: We used a Mendelian randomisation approach to test for a causal effect of age at menarche and age at menopause as surrogates for endogenous oestrogen exposure on CRC risk. Weighted genetic risk scores based on 358 single-nucleotide polymorphisms associated with age at menarche and 51 single-nucleotide polymorphisms associated with age at menopause were used to estimate the association with CRC risk using logistic regression in 12,944 women diagnosed with CRC and 10,741 women without CRC from three consortia. Sensitivity analyses were conducted to address pleiotropy and possible confounding by body mass index. RESULTS: Genetic risk scores for age at menarche (odds ratio per year 0.98, 95% confidence interval: 0.95-1.02) and age at menopause (odds ratio 0.98, 95% confidence interval: 0.94-1.01) were not significantly associated with CRC risk. The sensitivity analyses yielded similar results. CONCLUSIONS: Our study does not support a causal relationship between genetic risk scores for age at menarche and age at menopause and CRC risk.

9.
Int J Cancer ; 142(2): 290-296, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-28913878

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor with a five-year survival of less than 6%. Chronic pancreatitis (CP), an inflammatory process in of the pancreas, is a strong risk factor for PDAC. Several genetic polymorphisms have been discovered as susceptibility loci for both CP and PDAC. Since CP and PDAC share a consistent number of epidemiologic risk factors, the aim of this study was to investigate whether specific CP risk loci also contribute to PDAC susceptibility. We selected five common SNPs (rs11988997, rs379742, rs10273639, rs2995271 and rs12688220) that were identified as susceptibility markers for CP and analyzed them in 2,914 PDAC cases, 356 CP cases and 5,596 controls retrospectively collected in the context of the international PANDoRA consortium. We found a weak association between the minor allele of the PRSS1-PRSS2-rs10273639 and an increased risk of developing PDAC (ORhomozygous = 1.19, 95% CI 1.02-1.38, p = 0.023). Additionally all the SNPs confirmed statistically significant associations with risk of developing CP, the strongest being PRSS1-PRSS2-rs10273639 (ORheterozygous = 0.51, 95% CI 0.39-0.67, p = 1.10 × 10-6 ) and MORC4-rs 12837024 (ORhomozygous = 2.07 (1.55-2.77, ptrend = 0.7 × 10-11 ). Taken together, the results from our study do not support variants rs11988997, rs379742, rs10273639, rs2995271 and rs12688220 as strong predictors of PDAC risk, but further support the role of these SNPs in CP susceptibility. Our study suggests that CP and PDAC probably do not share genetic susceptibility, at least in terms of high frequency variants.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Ductal Pancreático/genética , Neoplasias Pancreáticas/genética , Pancreatite Crônica/genética , Polimorfismo de Nucleotídeo Único , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adulto , Idoso , Carcinoma Ductal Pancreático/patologia , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Neoplasias Pancreáticas/patologia , Pancreatite Crônica/patologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Tripsina/genética , Tripsinogênio/genética
10.
Am J Epidemiol ; 185(12): 1317-1326, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28459963

RESUMO

We studied the associations of leukocyte telomere length (LTL) with all-cause, cardiovascular disease, and cancer mortality in 12,199 adults participating in 2 population-based prospective cohort studies from Europe (ESTHER) and the United States (Nurses' Health Study). Blood samples were collected in 1989-1990 (Nurses' Health Study) and 2000-2002 (ESTHER). LTL was measured by quantitative polymerase chain reaction. We calculated z scores for LTL to standardize LTL measurements across the cohorts. Cox proportional hazards regression models were used to calculate relative mortality according to continuous levels and quintiles of LTL z scores. The hazard ratios obtained from each cohort were subsequently pooled by meta-analysis. Overall, 2,882 deaths were recorded during follow-up (Nurses' Health Study, 1989-2010; ESTHER, 2000-2015). LTL was inversely associated with age in both cohorts. After adjustment for age, a significant inverse trend of LTL with all-cause mortality was observed in both cohorts. In random-effects meta-analysis, age-adjusted hazard ratios for the shortest LTL quintile compared with the longest were 1.23 (95% confidence interval (CI): 1.04, 1.46) for all-cause mortality, 1.29 (95% CI: 0.83, 2.00) for cardiovascular mortality, and 1.10 (95% CI: 0.88, 1.37) for cancer mortality. In this study population with an age range of 43-75 years, we corroborated previous evidence suggesting that LTL predicts all-cause mortality beyond its association with age.


Assuntos
Doenças Cardiovasculares/mortalidade , Leucócitos/ultraestrutura , Neoplasias/mortalidade , Telômero/ultraestrutura , Adulto , Fatores Etários , Idoso , Causas de Morte , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Estados Unidos
11.
Cancer Epidemiol Biomarkers Prev ; 26(1): 126-135, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27697780

RESUMO

BACKGROUND: Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wide backbone, comprising 230,000 SNPs tagging most common genetic variants, together with dense mapping of known susceptibility regions, rare variants from sequencing experiments, pharmacogenetic markers, and cancer-related traits. METHODS: The OncoArray can be genotyped using a novel technology developed by Illumina to facilitate efficient genotyping. The consortium developed standard approaches for selecting SNPs for study, for quality control of markers, and for ancestry analysis. The array was genotyped at selected sites and with prespecified replicate samples to permit evaluation of genotyping accuracy among centers and by ethnic background. RESULTS: The OncoArray consortium genotyped 447,705 samples. A total of 494,763 SNPs passed quality control steps with a sample success rate of 97% of the samples. Participating sites performed ancestry analysis using a common set of markers and a scoring algorithm based on principal components analysis. CONCLUSIONS: Results from these analyses will enable researchers to identify new susceptibility loci, perform fine-mapping of new or known loci associated with either single or multiple cancers, assess the degree of overlap in cancer causation and pleiotropic effects of loci that have been identified for disease-specific risk, and jointly model genetic, environmental, and lifestyle-related exposures. IMPACT: Ongoing analyses will shed light on etiology and risk assessment for many types of cancer. Cancer Epidemiol Biomarkers Prev; 26(1); 126-35. ©2016 AACR.


Assuntos
Predisposição Genética para Doença/epidemiologia , Variação Genética/genética , Estudo de Associação Genômica Ampla/métodos , Neoplasias/genética , Polimorfismo de Nucleotídeo Único/genética , Feminino , Genótipo , Humanos , Masculino , Neoplasias/epidemiologia , Neoplasias/fisiopatologia , Prevalência , Prognóstico , Medição de Risco , Seleção Genética
12.
PLoS One ; 11(7): e0157521, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27379672

RESUMO

Genome-wide association studies (GWAS) have identified many common single nucleotide polymorphisms (SNPs) associated with colorectal cancer risk. These SNPs may tag correlated variants with biological importance. Fine-mapping around GWAS loci can facilitate detection of functional candidates and additional independent risk variants. We analyzed 11,900 cases and 14,311 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. To fine-map genomic regions containing all known common risk variants, we imputed high-density genetic data from the 1000 Genomes Project. We tested single-variant associations with colorectal tumor risk for all variants spanning genomic regions 250-kb upstream or downstream of 31 GWAS-identified SNPs (index SNPs). We queried the University of California, Santa Cruz Genome Browser to examine evidence for biological function. Index SNPs did not show the strongest association signals with colorectal tumor risk in their respective genomic regions. Bioinformatics analysis of SNPs showing smaller P-values in each region revealed 21 functional candidates in 12 loci (5q31.1, 8q24, 11q13.4, 11q23, 12p13.32, 12q24.21, 14q22.2, 15q13, 18q21, 19q13.1, 20p12.3, and 20q13.33). We did not observe evidence of additional independent association signals in GWAS-identified regions. Our results support the utility of integrating data from comprehensive fine-mapping with expanding publicly available genomic databases to help clarify GWAS associations and identify functional candidates that warrant more onerous laboratory follow-up. Such efforts may aid the eventual discovery of disease-causing variant(s).


Assuntos
Neoplasias Colorretais/genética , Predisposição Genética para Doença/genética , Variação Genética , Estudo de Associação Genômica Ampla/métodos , Células A549 , Adulto , Idoso , Idoso de 80 Anos ou mais , Células CACO-2 , Mapeamento Cromossômico , Neoplasias Colorretais/patologia , Biologia Computacional/métodos , Feminino , Genótipo , Células HCT116 , Células Hep G2 , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Sistema de Registros/estatística & dados numéricos , Fatores de Risco , Adulto Jovem
13.
Epigenomics ; 8(4): 487-99, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27035505

RESUMO

AIM: We aimed for an epigenome-wide identification of vitamin D-associated CpG sites in leukocyte DNA. MATERIALS & METHODS: Infinium HumanMethylation450BeadChip measurements in 402 Caucasian older men were evaluated for significant association with 25-hydroxy-vitamin (25(OH)D) using Spearman's correlation and median regression to adjust for confounding variables. A cross-validation approach as well as a bootstrapping procedure were implemented to determine the replicability of significant associations. Multiple testing was corrected for by Benjamini-Hochberg or Bonferroni. RESULTS: Although in the screening subcohorts significant associations of DNAm with 25(OH)D were observed in the validation cohorts these associations were not replicated after adjustment for potential confounders. At none of the 361,945 CpGs a significant association of DNAm with 25(OH)D was found in all 100 random bootstrap samples, but in comparison at 462 CpGs for the well-established association with age. CONCLUSION: Leukocyte DNAm was not associated with 25(OH)D levels after validation and consideration of confounders.


Assuntos
Ilhas de CpG , Metilação de DNA , Leucócitos/metabolismo , Vitamina D/análogos & derivados , Idoso , Epigenômica , Grupo com Ancestrais do Continente Europeu , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Vitamina D/sangue
14.
Br J Cancer ; 114(2): 221-9, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26766742

RESUMO

BACKGROUND: Menopausal hormone therapy (MHT) use has been consistently associated with a decreased risk of colorectal cancer (CRC) in women. Our aim was to use a genome-wide gene-environment interaction analysis to identify genetic modifiers of CRC risk associated with use of MHT. METHODS: We included 10 835 postmenopausal women (5419 cases and 5416 controls) from 10 studies. We evaluated use of any MHT, oestrogen-only (E-only) and combined oestrogen-progestogen (E+P) hormone preparations. To test for multiplicative interactions, we applied the empirical Bayes (EB) test as well as the Wald test in conventional case-control logistic regression as primary tests. The Cocktail test was used as secondary test. RESULTS: The EB test identified a significant interaction between rs964293 at 20q13.2/CYP24A1 and E+P (interaction OR (95% CIs)=0.61 (0.52-0.72), P=4.8 × 10(-9)). The secondary analysis also identified this interaction (Cocktail test OR=0.64 (0.52-0.78), P=1.2 × 10(-5) (alpha threshold=3.1 × 10(-4)). The ORs for association between E+P and CRC risk by rs964293 genotype were as follows: C/C, 0.96 (0.61-1.50); A/C, 0.61 (0.39-0.95) and A/A, 0.40 (0.22-0.73), respectively. CONCLUSIONS: Our results indicate that rs964293 modifies the association between E+P and CRC risk. The variant is located near CYP24A1, which encodes an enzyme involved in vitamin D metabolism. This novel finding offers additional insight into downstream pathways of CRC etiopathogenesis.


Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Terapia de Reposição de Estrogênios/métodos , Estrogênios/uso terapêutico , Progestinas/uso terapêutico , Vitamina D3 24-Hidroxilase/genética , Adenocarcinoma/epidemiologia , Idoso , Teorema de Bayes , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Quimioterapia Combinada , Feminino , Interação Gene-Ambiente , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores de Risco
15.
Diabetologia ; 59(1): 130-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26433941

RESUMO

AIMS/HYPOTHESIS: Development of type 2 diabetes depends on environmental and genetic factors. We investigated the epigenome-wide association of prevalent diabetes with DNA methylation (DNAm) in peripheral blood. METHODS: DNAm was measured in whole blood with the Illumina Infinium HumanMethylation450 BeadChip in two subsamples of participants from the ESTHER cohort study. Cohort 1 included 988 participants, who were consecutively recruited between July and October 2000 and cohort 2 included 527 randomly selected participants. The association of DNAm with prevalent type 2 diabetes at recruitment was estimated using median regression analysis adjusting for sex, age, BMI, smoking behaviour, cell composition and batch at 361,922 CpG sites. RESULTS: Type 2 diabetes was prevalent in 16% of the participants, and diabetes was poorly controlled in 45% of the diabetic patients. In cohort 1 (discovery) DNAm at 39 CpGs was significantly associated with prevalent diabetes after correction for multiple testing. In cohort 2 (replication) at one of these CpGs, DNAm was still significantly associated. Decreasing methylation levels at cg19693031 with increasing fasting glucose and HbA1c concentrations were observed using restricted cubic spline analysis. In diabetic patients with poorly controlled diabetes, the decrease in estimated DNAm levels was approximately 5% in comparison with participants free of diagnosed diabetes. CONCLUSIONS/INTERPRETATION: Cg19693031, which is located within the 3'-untranslated region of TXNIP, might play a role in the pathophysiology of type 2 diabetes. This result appears biologically plausible given that thioredoxin-interacting protein is overexpressed in diabetic animals and humans and 3'-untranslated regions are known to play a regulatory role in gene expression.


Assuntos
Metilação de DNA , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Epigênese Genética , Leucócitos/citologia , Regiões 3' não Traduzidas , Idoso , Glicemia/análise , Índice de Massa Corporal , Proteínas de Transporte/metabolismo , Estudos de Coortes , Ilhas de CpG , Estudos Transversais , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Fumar , Inquéritos e Questionários
16.
Environ Health Perspect ; 124(1): 67-74, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26017925

RESUMO

BACKGROUND: With epigenome-wide mapping of DNA methylation, a number of novel smoking-associated loci have been identified. OBJECTIVES: We aimed to assess dose-response relationships of methylation at the top hits from the epigenome-wide methylation studies with smoking exposure as well as with total and cause-specific mortality. METHODS: In a population-based prospective cohort study in Germany, methylation was quantified in baseline blood DNA of 1,000 older adults by the Illumina 450K assay. Deaths were recorded during a median follow-up of 10.3 years. Dose-response relationships of smoking exposure with methylation at nine CpGs were modeled by restricted cubic spline regression. Associations of individual and aggregate methylation patterns with all-cause, cardiovascular, and cancer mortality were assessed by multiple Cox regression. RESULTS: Clear dose-response relationships with respect to current and lifetime smoking intensity were consistently observed for methylation at six of the nine CpGs. Seven of the nine CpGs were also associated with mortality outcomes to various extents. A methylation score based on the top two CpGs (cg05575921 and cg06126421) showed the strongest associations with all-cause, cardiovascular, and cancer mortality, with adjusted hazard ratios (95% CI) of 3.59 (2.10, 6.16), 7.41 (2.81, 19.54), and 2.48 (1.01, 6.08), respectively, for participants with methylation levels in the lowest quartile at both CpGs. Adding methylation at those two CpGs into a model that included the variables of the Systematic Coronary Risk Evaluation chart for fatal cardiovascular risk prediction improved the predictive discrimination. CONCLUSION: The novel methylation biomarkers are highly informative for both smoking exposure and smoking-related mortality outcomes. In particular, these biomarkers may substantially improve cardiovascular risk prediction. Nevertheless, the findings of the present study need to be further validated in additional large longitudinal studies. CITATION: Zhang Y, Schöttker B, Florath I, Stock C, Butterbach K, Holleczek B, Mons U, Brenner H. 2016. Smoking-associated DNA methylation biomarkers and their predictive value for all-cause and cardiovascular mortality. Environ Health Perspect 124:67-74; http://dx.doi.org/10.1289/ehp.1409020.


Assuntos
Biomarcadores/sangue , Metilação de DNA/efeitos dos fármacos , Fumar/efeitos adversos , Idoso , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos
17.
Exp Gerontol ; 74: 1-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26657493

RESUMO

OBJECTIVE: Telomere length (TL) has been proposed as a biomarker of ageing, which might be used to identify individuals at higher risk of age-related diseases. Obesity is a well-known risk factor for several diseases. This study aims to analyse the associations of BMI with TL and the rate of TL change in older adults. METHODS: Leukocyte TL (LTL) was measured by quantitative PCR in blood samples of 3600 older adults aged 50-75 years obtained at the baseline examination of a population-based cohort study in Germany. For longitudinal analyses, measurements were repeated in blood samples obtained at 8-year follow-up from 1000 participants. Multivariate linear regression models were used to estimate associations of BMI with LTL and changes in LTL over time. RESULTS: LTL was inversely associated with age (r = -0.090, p < 0.0001). BMI and LTL associations varied according to age (p for interaction = 0.021). BMI was significantly inversely associated with LTL in those younger than 60 years (-6 basepairs per 1 kg/m(2) difference in BMI). In particular, weight gain during adulthood was inversely associated with LTL in a dose-response manner in this age group, with those having gained ≥ 30 kg having significantly shorter telomeres (-209 basepairs) than those who maintained their weight. No clear patterns were observed between any of BMI-related variables and the rate of LTL change. CONCLUSIONS: Our cross-sectional analysis supports suggestions that weight gain during adulthood and obesity may contribute to shorter telomere length below 60 years of age, but this relationship could not be shown longitudinally.


Assuntos
Envelhecimento/genética , Índice de Massa Corporal , Obesidade/genética , Obesidade/fisiopatologia , Encurtamento do Telômero , Telômero/genética , Adiposidade , Fatores Etários , Idoso , Envelhecimento/sangue , Estudos Transversais , Feminino , Alemanha , Humanos , Leucócitos/metabolismo , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/diagnóstico , Reação em Cadeia da Polimerase , Fatores de Risco , Telômero/metabolismo , Fatores de Tempo , Ganho de Peso
19.
Exp Gerontol ; 70: 18-25, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26255046

RESUMO

BACKGROUND & AIMS: Leukocyte telomere length (LTL) shortens with age and short LTL has been associated with increased mortality and increased risk for some age-related outcomes. This study aims to analyse the associations of smoking habits with LTL and rate of LTL change per year in older adults. METHODS: LTL was measured by quantitative PCR at baseline in 3600 older adults, who were enrolled in a population-based cohort study in Germany. For longitudinal analyses, measurements were repeated in blood samples obtained at 8-year follow-up from 1000 participants. Terminal Restriction Fragment analysis was additionally performed in a sub-sample to obtain absolute LTL in base pairs. Multivariate linear regression models were used to estimate associations of smoking habits with baseline LTL and changes in LTL over time. RESULTS: LTL was inversely associated with age (r=-0.090, p<0.0001). Women had longer LTL than men (p<0.0001). Smoking was inversely associated with LTL. On average, current smokers had 73 base pairs (BP) shorter LTL compared to never smokers. Smoking intensity and pack-years of smoking were also inversely associated with LTL, and a positive association was observed with years since smoking cessation. Slower LTL attrition rates were observed in ever smokers over 8years of follow-up. CONCLUSIONS: Our cross-sectional analysis supports suggestions that smoking might contribute to shortening of LTL but this relationship could not be shown longitudinally. The overall rather small effect sizes observed for smoking-related variables suggest that LTL reflects smoking-related health hazards only to a very limited extent.


Assuntos
Envelhecimento/genética , Leucócitos/ultraestrutura , Fumar/genética , Homeostase do Telômero/fisiologia , Idoso , Envelhecimento/sangue , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fumar/sangue , Telômero/fisiologia , Encurtamento do Telômero/fisiologia
20.
Genes Chromosomes Cancer ; 54(9): 583-94, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26173806

RESUMO

Long-lasting oxidative stress exposure may lead to relatively stable epigenetic modifications of the DNA in order to activate anti-oxidative defence mechanisms. Oxidative stress related DNA methylation may therefore be associated (causally or as a by-product) with cancer. We measured derivatives of reactive oxygen metabolites (D-ROM), total thiol levels (TTL) and DNA methylation with the Illumina Infinium 450K BeadChip in three samples of German individuals aged ≥50 years: n = 1,000 ESTHER study baseline participants (DNA methylation only), n = 99 ESTHER eight-year follow-up participants and n = 142 participants of the BLITZ study. The correlation coefficient of methylation at cg10342304 and D-ROM in the ESTHER 8-year follow-up sample (r = -0.427; P = 1 × 10(-5)) was replicated with a P-value indicating statistical significance after correction for multiple testing in the BLITZ sample (r = -0.192; P = 0.022). The association was robust to adjusting for potential confounders. In the ESTHER baseline sample, the hazard ratio for cancer development in 11 years of follow-up comparing bottom and top quartile of DNA methylation at cg10342304 was 1.86 (95%-confidence-interval 1.01-3.43). In summary, this first epigenome-wide screening and replication study with oxidative status markers observed a negative correlation of D-ROM levels and DNA methylation at cg10342304 in two independent cohorts. This CpG site is located in the body region of the nucleoredoxin gene. The nucleoredoxin protein is a redox-dependent inhibitor of the Wnt/ß-catenin signaling pathway, a well-characterized cancer pathway. If the observed CpG-cancer association can be successfully replicated by other studies, this epigenetic marker could be an interesting biomarker of cancer risk.


Assuntos
Biomarcadores Tumorais/sangue , Epigênese Genética , Neoplasias/sangue , Neoplasias/genética , Oxirredução , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Ilhas de CpG , Metilação de DNA , Replicação do DNA , Feminino , Estudo de Associação Genômica Ampla , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/sangue
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