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1.
Int J Cancer ; 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31696517

RESUMO

We have recently completed the largest GWAS on lung cancer including 29,266 cases and 56,450 controls of European descent. The goal of this study has been to integrate the complete GWAS results with a large-scale expression quantitative trait loci (eQTL) mapping study in human lung tissues (n=1,038) to identify candidate causal genes for lung cancer. We performed transcriptome-wide association study (TWAS) for lung cancer overall, by histology (adenocarcinoma, squamous cell carcinoma, small cell lung cancer) and smoking subgroups (never- and ever-smokers). We performed replication analysis using lung data from the Genotype-Tissue Expression (GTEx) project. DNA damage assays were performed in human lung fibroblasts for selected TWAS genes. As expected, the main TWAS signal for all histological subtypes and ever-smokers was on chromosome 15q25. The gene most strongly associated with lung cancer at this locus using the TWAS approach was IREB2 (PTWAS =1.09E-99), where lower predicted expression increased lung cancer risk. A new lung adenocarcinoma susceptibility locus was revealed on 9p13.3 and associated with higher predicted expression of AQP3 (PTWAS =3.72E-6). Among the 45 previously described lung cancer GWAS loci, we mapped candidate target gene for 17 of them. The association AQP3-adenocarcinoma on 9p13.3 was replicated using GTEx (PTWAS =6.55E-5). Consistent with the effect of risk alleles on gene expression levels, IREB2 knockdown and AQP3 overproduction promote endogenous DNA damage. These findings indicate genes whose expression in lung tissue directly influence lung cancer risk. This article is protected by copyright. All rights reserved.

3.
Int J Epidemiol ; 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31549173

RESUMO

BACKGROUND: DNA methylation changes in peripheral blood have recently been identified in relation to lung cancer risk. Some of these changes have been suggested to mediate part of the effect of smoking on lung cancer. However, limitations with conventional mediation analyses mean that the causal nature of these methylation changes has yet to be fully elucidated. METHODS: We first performed a meta-analysis of four epigenome-wide association studies (EWAS) of lung cancer (918 cases, 918 controls). Next, we conducted a two-sample Mendelian randomization analysis, using genetic instruments for methylation at CpG sites identified in the EWAS meta-analysis, and 29 863 cases and 55 586 controls from the TRICL-ILCCO lung cancer consortium, to appraise the possible causal role of methylation at these sites on lung cancer. RESULTS: Sixteen CpG sites were identified from the EWAS meta-analysis [false discovery rate (FDR) < 0.05], for 14 of which we could identify genetic instruments. Mendelian randomization provided little evidence that DNA methylation in peripheral blood at the 14 CpG sites plays a causal role in lung cancer development (FDR > 0.05), including for cg05575921-AHRR where methylation is strongly associated with both smoke exposure and lung cancer risk. CONCLUSIONS: The results contrast with previous observational and mediation analysis, which have made strong claims regarding the causal role of DNA methylation. Thus, previous suggestions of a mediating role of methylation at sites identified in peripheral blood, such as cg05575921-AHRR, could be unfounded. However, this study does not preclude the possibility that differential DNA methylation at other sites is causally involved in lung cancer development, especially within lung tissue.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31315910

RESUMO

BACKGROUND: The 5-year mortality rate for pancreatic cancer is among the highest of all cancers. Greater understanding of underlying causes could inform population-wide intervention strategies for prevention. Summary genetic data from genome-wide association studies (GWAS) have become available for thousands of phenotypes. These data can be exploited in Mendelian randomization (MR) phenome-wide association studies (PheWAS) to efficiently screen the phenome for potential determinants of disease risk. METHODS: We conducted an MR-PheWAS of pancreatic cancer using 486 phenotypes, proxied by 9,124 genetic variants, and summary genetic data from a GWAS of pancreatic cancer (7,110 cancer cases, 7,264 controls). ORs and 95% confidence intervals per 1 SD increase in each phenotype were generated. RESULTS: We found evidence that previously reported risk factors of body mass index (BMI; 1.46; 1.20-1.78) and hip circumference (1.42; 1.21-1.67) were associated with pancreatic cancer. We also found evidence of novel associations with metabolites that have not previously been implicated in pancreatic cancer: ADpSGEGDFXAEGGGVR*, a fibrinogen-cleavage peptide (1.60; 1.31-1.95), and O-sulfo-l-tyrosine (0.58; 0.46-0.74). An inverse association was also observed with lung adenocarcinoma (0.63; 0.54-0.74). CONCLUSIONS: Markers of adiposity (BMI and hip circumference) are potential intervention targets for pancreatic cancer prevention. Further clarification of the causal relevance of the fibrinogen-cleavage peptides and O-sulfo-l-tyrosine in pancreatic cancer etiology is required, as is the basis of our observed association with lung adenocarcinoma. IMPACT: For pancreatic cancer, MR-PheWAS can augment existing risk factor knowledge and generate novel hypotheses to investigate.

5.
Cancer Epidemiol Biomarkers Prev ; 28(5): 935-942, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30700444

RESUMO

BACKGROUND: Platelets are a critical element in coagulation and inflammation, and activated platelets are linked to cancer risk through diverse mechanisms. However, a causal relationship between platelets and risk of lung cancer remains unclear. METHODS: We performed single and combined multiple instrumental variable Mendelian randomization analysis by an inverse-weighted method, in addition to a series of sensitivity analyses. Summary data for associations between SNPs and platelet count are from a recent publication that included 48,666 Caucasian Europeans, and the International Lung Cancer Consortium and Transdisciplinary Research in Cancer of the Lung data consisting of 29,266 cases and 56,450 controls to analyze associations between candidate SNPs and lung cancer risk. RESULTS: Multiple instrumental variable analysis incorporating six SNPs showed a 62% increased risk of overall non-small cell lung cancer [NSCLC; OR, 1.62; 95% confidence interval (CI), 1.15-2.27; P = 0.005] and a 200% increased risk for small-cell lung cancer (OR, 3.00; 95% CI, 1.27-7.06; P = 0.01). Results showed only a trending association with NSCLC histologic subtypes, which may be due to insufficient sample size and/or weak effect size. A series of sensitivity analysis retained these findings. CONCLUSIONS: Our findings suggest a causal relationship between elevated platelet count and increased risk of lung cancer and provide evidence of possible antiplatelet interventions for lung cancer prevention. IMPACT: These findings provide a better understanding of lung cancer etiology and potential evidence for antiplatelet interventions for lung cancer prevention.

6.
PLoS Med ; 16(1): e1002724, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30605491

RESUMO

BACKGROUND: Several obesity-related factors have been associated with renal cell carcinoma (RCC), but it is unclear which individual factors directly influence risk. We addressed this question using genetic markers as proxies for putative risk factors and evaluated their relation to RCC risk in a mendelian randomization (MR) framework. This methodology limits bias due to confounding and is not affected by reverse causation. METHODS AND FINDINGS: Genetic markers associated with obesity measures, blood pressure, lipids, type 2 diabetes, insulin, and glucose were initially identified as instrumental variables, and their association with RCC risk was subsequently evaluated in a genome-wide association study (GWAS) of 10,784 RCC patients and 20,406 control participants in a 2-sample MR framework. The effect on RCC risk was estimated by calculating odds ratios (ORSD) for a standard deviation (SD) increment in each risk factor. The MR analysis indicated that higher body mass index increases the risk of RCC (ORSD: 1.56, 95% confidence interval [CI] 1.44-1.70), with comparable results for waist-to-hip ratio (ORSD: 1.63, 95% CI 1.40-1.90) and body fat percentage (ORSD: 1.66, 95% CI 1.44-1.90). This analysis further indicated that higher fasting insulin (ORSD: 1.82, 95% CI 1.30-2.55) and diastolic blood pressure (DBP; ORSD: 1.28, 95% CI 1.11-1.47), but not systolic blood pressure (ORSD: 0.98, 95% CI 0.84-1.14), increase the risk for RCC. No association with RCC risk was seen for lipids, overall type 2 diabetes, or fasting glucose. CONCLUSIONS: This study provides novel evidence for an etiological role of insulin in RCC, as well as confirmatory evidence that obesity and DBP influence RCC risk.


Assuntos
Carcinoma de Células Renais/etiologia , Neoplasias Renais/etiologia , Obesidade/complicações , Glicemia/análise , Pressão Sanguínea , Índice de Massa Corporal , Carcinoma de Células Renais/genética , Diabetes Mellitus Tipo 2/complicações , Feminino , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Humanos , Insulina/sangue , Neoplasias Renais/genética , Lipídeos/sangue , Masculino , Análise da Randomização Mendeliana , Obesidade/genética , Fatores de Risco
7.
Int J Cancer ; 2018 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-30499135

RESUMO

Vitamin B supplementation can have side effects for human health, including cancer risk. We aimed to elucidate the role of vitamin B12 in lung cancer aetiology via direct measurements of pre-diagnostic circulating vitamin B12 concentrations in a nested case-control study, complemented with a Mendelian randomization (MR) approach in an independent case-control sample. We used pre-diagnostic biomarker data from 5,183 case-control pairs nested within 20 prospective cohorts, and genetic data from 29,266 cases and 56,450 controls. Exposures included directly measured circulating vitamin B12 in pre-diagnostic blood samples from the nested case-control study, and 8 single nucleotide polymorphisms associated with vitamin B12 concentrations in the MR study. Our main outcome of interest was increased risk for lung cancer, overall and by histological subtype, per increase in circulating vitamin B12 concentrations. We found circulating vitamin B12 to be positively associated with overall lung cancer risk in a dose response fashion (odds ratio for a doubling in B12 [ORlog2B12 ] = 1.15, 95% confidence interval (95%CI) = 1.06-1.25). The MR analysis based on 8 genetic variants also indicated that genetically determined higher vitamin B12 concentrations were positively associated with overall lung cancer risk (OR per 150 pmol/L standard deviation increase in B12 [ORSD ]= 1.08, 95%CI= 1.00-1.16). Considering the consistency of these two independent and complementary analyses, these findings support the hypothesis that high vitamin B12 status increases the risk of lung cancer. This article is protected by copyright. All rights reserved.

8.
Nat Commun ; 9(1): 3221, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-30104567

RESUMO

Genome-wide association studies (GWAS) identified the chromosome 15q25.1 locus as a leading susceptibility region for lung cancer. However, the pathogenic pathways, through which susceptibility SNPs within chromosome 15q25.1 affects lung cancer risk, have not been explored. We analyzed three cohorts with GWAS data consisting 42,901 individuals and lung expression quantitative trait loci (eQTL) data on 409 individuals to identify and validate the underlying pathways and to investigate the combined effect of genes from the identified susceptibility pathways. The KEGG neuroactive ligand receptor interaction pathway, two Reactome pathways, and 22 Gene Ontology terms were identified and replicated to be significantly associated with lung cancer risk, with P values less than 0.05 and FDR less than 0.1. Functional annotation of eQTL analysis results showed that the neuroactive ligand receptor interaction pathway and gated channel activity were involved in lung cancer risk. These pathways provide important insights for the etiology of lung cancer.

10.
BMJ ; 361: k1767, 2018 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769355

RESUMO

OBJECTIVE: To determine whether body mass index, body fat percentage, and waist circumference influence smoking status and intensity. DESIGN: Mendelian randomisation study. SETTING: UK Biobank, with replication of results from the Tobacco and Genetics (TAG) consortium. PARTICIPANTS: European descent participants from the UK Biobank cohort (n=372 791) and the TAG consortium (n=74 035). MAIN OUTCOME MEASURES: Risk of current and past smoking, number of cigarettes smoked per day, age of smoking initiation. RESULTS: The Mendelian randomisation analysis indicated that each standard deviation increment in body mass index (4.6) increased the risk of being a smoker (odds ratio 1.18 (95% confidence interval 1.13 to 1.23), P<0.001). This association was replicated in the TAG consortium data (1.19 (1.06 to 1.33), P=0.003). Furthermore, each standard deviation increment in body mass index was estimated to increase smoking intensity by 0.88 cigarettes per day (95% confidence interval 0.50 to 1.26, P<0.001) in UK Biobank and 1.27 cigarettes per day in the TAG consortium (0.46 to 2.07, P=0.002). Similar results were also seen for body fat percentage and waist circumference in both UK Biobank and the TAG consortium data. CONCLUSIONS: These results strongly suggest that higher adiposity influences smoking behaviour and could have implications for the implementation of public health interventions aiming to reduce the prevalence of these important risk factors.

11.
Sci Rep ; 8(1): 4534, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29540730

RESUMO

With the aim to dissect the effect of adult height on head and neck cancer (HNC), we use the Mendelian randomization (MR) approach to test the association between genetic instruments for height and the risk of HNC. 599 single nucleotide polymorphisms (SNPs) were identified as genetic instruments for height, accounting for 16% of the phenotypic variation. Genetic data concerning HNC cases and controls were obtained from a genome-wide association study. Summary statistics for genetic association were used in complementary MR approaches: the weighted genetic risk score (GRS) and the inverse-variance weighted (IVW). MR-Egger regression was used for sensitivity analysis and pleiotropy evaluation. From the GRS analysis, one standard deviation (SD) higher height (6.9 cm; due to genetic predisposition across 599 SNPs) raised the risk for HNC (Odds ratio (OR), 1.14; 95% Confidence Interval (95%CI), 0.99-1.32). The association analyses with potential confounders revealed that the GRS was associated with tobacco smoking (OR = 0.80, 95% CI (0.69-0.93)). MR-Egger regression did not provide evidence of overall directional pleiotropy. Our study indicates that height is potentially associated with HNC risk. However, the reported risk could be underestimated since, at the genetic level, height emerged to be inversely associated with smoking.

12.
J Natl Cancer Inst ; 109(9)2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28954281

RESUMO

Background: Risk factors for pancreatic cancer include a cluster of metabolic conditions such as obesity, hypertension, dyslipidemia, insulin resistance, and type 2 diabetes. Given that these risk factors are correlated, separating out causal from confounded effects is challenging. Mendelian randomization (MR), or the use of genetic instrumental variables, may facilitate the identification of the metabolic drivers of pancreatic cancer. Methods: We identified genetic instruments for obesity, body shape, dyslipidemia, insulin resistance, and type 2 diabetes in order to evaluate their causal role in pancreatic cancer etiology. These instruments were analyzed in relation to risk using a likelihood-based MR approach within a series of 7110 pancreatic cancer patients and 7264 control subjects using genome-wide data from the Pancreatic Cancer Cohort Consortium (PanScan) and the Pancreatic Cancer Case-Control Consortium (PanC4). Potential unknown pleiotropic effects were assessed using a weighted median approach and MR-Egger sensitivity analyses. Results: Results indicated a robust causal association of increasing body mass index (BMI) with pancreatic cancer risk (odds ratio [OR] = 1.34, 95% confidence interval [CI] = 1.09 to 1.65, for each standard deviation increase in BMI [4.6 kg/m2]). There was also evidence that genetically increased fasting insulin levels were causally associated with an increased risk of pancreatic cancer (OR = 1.66, 95% CI = 1.05 to 2.63, per SD [44.4 pmol/L]). Notably, no evidence of a causal relationship was observed for type 2 diabetes, nor for dyslipidemia. Sensitivity analyses did not indicate that pleiotropy was an important source of bias. Conclusions: Our results suggest a causal role of BMI and fasting insulin in pancreatic cancer etiology.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Metabolismo Energético , Obesidade/complicações , Neoplasias Pancreáticas/etiologia , Neoplasias Pancreáticas/metabolismo , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Insulina/metabolismo , Resistência à Insulina , Funções Verossimilhança , Masculino , Razão de Chances , Neoplasias Pancreáticas/epidemiologia , Polimorfismo de Nucleotídeo Único , Vigilância da População , Característica Quantitativa Herdável , Fatores de Risco
13.
Eur Urol ; 72(5): 747-754, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28797570

RESUMO

BACKGROUND: Relative telomere length in peripheral blood leukocytes has been evaluated as a potential biomarker for renal cell carcinoma (RCC) risk in several studies, with conflicting findings. OBJECTIVE: We performed an analysis of genetic variants associated with leukocyte telomere length to assess the relationship between telomere length and RCC risk using Mendelian randomization, an approach unaffected by biases from temporal variability and reverse causation that might have affected earlier investigations. DESIGN, SETTING, AND PARTICIPANTS: Genotypes from nine telomere length-associated variants for 10 784 cases and 20 406 cancer-free controls from six genome-wide association studies (GWAS) of RCC were aggregated into a weighted genetic risk score (GRS) predictive of leukocyte telomere length. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Odds ratios (ORs) relating the GRS and RCC risk were computed in individual GWAS datasets and combined by meta-analysis. RESULTS AND LIMITATIONS: Longer genetically inferred telomere length was associated with an increased risk of RCC (OR=2.07 per predicted kilobase increase, 95% confidence interval [CI]:=1.70-2.53, p<0.0001). As a sensitivity analysis, we excluded two telomere length variants in linkage disequilibrium (R2>0.5) with GWAS-identified RCC risk variants (rs10936599 and rs9420907) from the telomere length GRS; despite this exclusion, a statistically significant association between the GRS and RCC risk persisted (OR=1.73, 95% CI=1.36-2.21, p<0.0001). Exploratory analyses for individual histologic subtypes suggested comparable associations with the telomere length GRS for clear cell (N=5573, OR=1.93, 95% CI=1.50-2.49, p<0.0001), papillary (N=573, OR=1.96, 95% CI=1.01-3.81, p=0.046), and chromophobe RCC (N=203, OR=2.37, 95% CI=0.78-7.17, p=0.13). CONCLUSIONS: Our investigation adds to the growing body of evidence indicating some aspect of longer telomere length is important for RCC risk. PATIENT SUMMARY: Telomeres are segments of DNA at chromosome ends that maintain chromosomal stability. Our study investigated the relationship between genetic variants associated with telomere length and renal cell carcinoma risk. We found evidence suggesting individuals with inherited predisposition to longer telomere length are at increased risk of developing renal cell carcinoma.


Assuntos
Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Polimorfismo de Nucleotídeo Único , Homeostase do Telômero , Telômero/genética , Carcinoma de Células Renais/sangue , Carcinoma de Células Renais/patologia , Estudos de Casos e Controles , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Neoplasias Renais/sangue , Neoplasias Renais/patologia , Leucócitos/química , Análise da Randomização Mendeliana , Razão de Chances , Fenótipo , Medição de Risco , Fatores de Risco , Telômero/patologia
14.
PLoS One ; 12(6): e0177875, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28594918

RESUMO

BACKGROUND: Assessing the relationship between lung cancer and metabolic conditions is challenging because of the confounding effect of tobacco. Mendelian randomization (MR), or the use of genetic instrumental variables to assess causality, may help to identify the metabolic drivers of lung cancer. METHODS AND FINDINGS: We identified genetic instruments for potential metabolic risk factors and evaluated these in relation to risk using 29,266 lung cancer cases (including 11,273 adenocarcinomas, 7,426 squamous cell and 2,664 small cell cases) and 56,450 controls. The MR risk analysis suggested a causal effect of body mass index (BMI) on lung cancer risk for two of the three major histological subtypes, with evidence of a risk increase for squamous cell carcinoma (odds ratio (OR) [95% confidence interval (CI)] = 1.20 [1.01-1.43] and for small cell lung cancer (OR [95%CI] = 1.52 [1.15-2.00]) for each standard deviation (SD) increase in BMI [4.6 kg/m2]), but not for adenocarcinoma (OR [95%CI] = 0.93 [0.79-1.08]) (Pheterogeneity = 4.3x10-3). Additional analysis using a genetic instrument for BMI showed that each SD increase in BMI increased cigarette consumption by 1.27 cigarettes per day (P = 2.1x10-3), providing novel evidence that a genetic susceptibility to obesity influences smoking patterns. There was also evidence that low-density lipoprotein cholesterol was inversely associated with lung cancer overall risk (OR [95%CI] = 0.90 [0.84-0.97] per SD of 38 mg/dl), while fasting insulin was positively associated (OR [95%CI] = 1.63 [1.25-2.13] per SD of 44.4 pmol/l). Sensitivity analyses including a weighted-median approach and MR-Egger test did not detect other pleiotropic effects biasing the main results. CONCLUSIONS: Our results are consistent with a causal role of fasting insulin and low-density lipoprotein cholesterol in lung cancer etiology, as well as for BMI in squamous cell and small cell carcinoma. The latter relation may be mediated by a previously unrecognized effect of obesity on smoking behavior.


Assuntos
Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Análise da Randomização Mendeliana , Obesidade/complicações , Índice de Massa Corporal , Jejum , Humanos , Insulina/sangue , Resistência à Insulina , Funções Verossimilhança , Lipídeos/sangue , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/complicações , Obesidade/sangue , Fenótipo , Polimorfismo de Nucleotídeo Único , Fatores de Risco
15.
Nat Genet ; 49(7): 1126-1132, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28604730

RESUMO

Although several lung cancer susceptibility loci have been identified, much of the heritability for lung cancer remains unexplained. Here 14,803 cases and 12,262 controls of European descent were genotyped on the OncoArray and combined with existing data for an aggregated genome-wide association study (GWAS) analysis of lung cancer in 29,266 cases and 56,450 controls. We identified 18 susceptibility loci achieving genome-wide significance, including 10 new loci. The new loci highlight the striking heterogeneity in genetic susceptibility across the histological subtypes of lung cancer, with four loci associated with lung cancer overall and six loci associated with lung adenocarcinoma. Gene expression quantitative trait locus (eQTL) analysis in 1,425 normal lung tissue samples highlights RNASET2, SECISBP2L and NRG1 as candidate genes. Other loci include genes such as a cholinergic nicotinic receptor, CHRNA2, and the telomere-related genes OFBC1 and RTEL1. Further exploration of the target genes will continue to provide new insights into the etiology of lung cancer.


Assuntos
Estudo de Associação Genômica Ampla , Neoplasias Pulmonares/genética , Adenocarcinoma/genética , Adenocarcinoma de Pulmão , Adulto , Idoso , Mapeamento Cromossômico , Grupo com Ancestrais do Continente Europeu/genética , Saúde da Família , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etnologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Fumar/epidemiologia , Homeostase do Telômero/genética
16.
Eur J Hum Genet ; 25(4): 472-476, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28098150

RESUMO

This study tries to find detectable signals of gene flow of Sub-Saharan origin into the Mediterranean in four genomic regions previously associated with coronary artery disease. A total of 366 single-nucleotide polymorphisms were genotyped in 772 individuals from 10 Mediterranean countries. Population structure analyses were performed, in which a noticeable Sub-Saharan component was found in the studied samples. The overall percentage of this Sub-Saharan component presents differences between the two Mediterranean coasts. D-statistics suggest possible Sub-Saharan introgression into one of the studied genomic regions (10q11). We also found differences in linkage disequilibrium patterns between the two Mediterranean coasts, possibly attributable to differential Sub-Saharan admixture. Our results confirm the potentially important role of human demographic history when performing epidemiological studies.


Assuntos
Doença da Artéria Coronariana/genética , Fluxo Gênico , Loci Gênicos , Polimorfismo de Nucleotídeo Único , África ao Sul do Saara , Doença da Artéria Coronariana/etnologia , Humanos , Desequilíbrio de Ligação , Região do Mediterrâneo
17.
Sci Rep ; 6: 31121, 2016 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-27487993

RESUMO

Body mass index (BMI) is inversely associated with lung cancer risk in observational studies, even though it increases the risk of several other cancers, which could indicate confounding by tobacco smoking or reverse causality. We used the two-sample Mendelian randomization (MR) approach to circumvent these limitations of observational epidemiology by constructing a genetic instrument for BMI, based on results from the GIANT consortium, which was evaluated in relation to lung cancer risk using GWAS results on 16,572 lung cancer cases and 21,480 controls. Results were stratified by histological subtype, smoking status and sex. An increase of one standard deviation (SD) in BMI (4.65 Kg/m(2)) raised the risk for lung cancer overall (OR = 1.13; P = 0.10). This was driven by associations with squamous cell (SQ) carcinoma (OR = 1.45; P = 1.2 × 10(-3)) and small cell (SC) carcinoma (OR = 1.81; P = 0.01). An inverse trend was seen for adenocarcinoma (AD) (OR = 0.82; P = 0.06). In stratified analyses, a 1 SD increase in BMI was inversely associated with overall lung cancer in never smokers (OR = 0.50; P = 0.02). These results indicate that higher BMI may increase the risk of certain types of lung cancer, in particular SQ and SC carcinoma.


Assuntos
Neoplasias Pulmonares/patologia , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Análise da Randomização Mendeliana/métodos , Fatores de Risco , Fumar/patologia
18.
Am J Phys Anthropol ; 161(4): 634-645, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27500977

RESUMO

OBJECTIVES: The population analysis of cardiovascular risk and non-risk genetic variation can help to identify adaptive or random demographic processes that shaped coronary incidence variation across geography. MATERIAL AND METHODS: In this study, 114 single nucleotide polymorphisms and 17 tandem repeat polymorphisms from Nitric Oxide Synthases (NOS) regions were analyzed in 1686 individuals from 35 populations from Europe, North Africa, and the Middle East. NOS genes encode for key enzymes on nitric oxide availability, which is involved in several cardiovascular processes. These genetic variations were used to test for selection and to infer the population structure of NOS regions. Moreover, we tested whether the variation in the incidence of coronary events and in the levels of classical risk factors in 11 of these European populations could be explained by the population structure estimates. RESULTS: Our results supported, first, the absence of clear signs of selection for NOS genetic variants associated with cardiovascular diseases, and second, the presence of a continuous genetic pattern of variation across European and North African populations without a Mediterranean barrier for gene flow. Finally, population structure estimates from NOS regions are closely correlated with coronary event rates and classical risk parameters (explaining 39-98%) among European populations. CONCLUSION: Our results reinforce the hypothesis that genetic bases of cardiovascular diseases and associated complex phenotypes could be geographically shaped by random demographic processes.


Assuntos
Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/genética , Grupo com Ancestrais do Continente Europeu/genética , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Óxido Nítrico Sintase/genética , África do Norte , Europa (Continente) , Feminino , Predisposição Genética para Doença/genética , Genética Populacional , Humanos , Masculino , Oriente Médio , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
19.
Am J Hum Biol ; 28(6): 905-912, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27338933

RESUMO

OBJECTIVES: The aim of this study is to determine whether the LIN28B gene is differentially distributed in the Mediterranean region through the analysis of the allele distribution of three single nucleotide polymorphisms (SNPs), namely rs7759938, rs314277, and rs221639, in 24 populations. These SNPs have been recently related to the age at menarche, pubertal height growth, peripubertal body mass index, levels of prenatal testosterone exposure, and cancer survival. METHODS: A total of 1,197 DNA samples were genotyped. The allele frequencies were used to determine the relationship between populations, with data from the 1000 Genomes Project being used for external comparisons. The genotype distributions and the population structure between populations and groups of populations were determined. RESULTS: The population results indicate a significant degree of variation (FST = 0.043, P < 0.0001). Allele frequencies show significant differences among populations. A hierarchical variance analysis is consistent with a primary differentiation between populations on the North and South coasts of the Mediterranean. This difference is especially evident in the unexpected distribution of the SNP rs221639, which shows one of the highest FST (11.5%, P < 0.0001) values described in the Mediterranean region thus far. CONCLUSION: The population differentiation and the structuring of the genetic variance, in agreement with previous studies, indicate that the SNPs in question are good tools for the study of human populations, even at a microgeographic level. Am. J. Hum. Biol. 28:905-912, 2016. © 2016Wiley Periodicals, Inc.


Assuntos
Frequência do Gene , Polimorfismo de Nucleotídeo Único , Proteínas de Ligação a RNA/genética , África do Norte , Humanos , Região do Mediterrâneo
20.
J Epidemiol ; 26(5): 264-71, 2016 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-26780859

RESUMO

BACKGROUND: In recent years, several genomic regions have been robustly associated with coronary artery disease (CAD) in different genome-wide association studies (GWASs) conducted mainly in people of European descent. These kinds of data are lacking in African populations, even though heart diseases are a major cause of premature death and disability. METHODS: Here, 384 single nucleotide polymorphisms (SNPs) in the top four CAD risk regions (1p13, 1q41, 9p21, and 10q11) were genotyped in 274 case-control samples from Morocco and Tunisia, with the aim of analyzing for the first time if the associations found in European populations were transferable to North Africans. RESULTS: The results indicate that, as in Europe, these four genetic regions are also important for CAD risk in North Africa. However, the individual SNPs associated with CAD in Africa are different from those identified in Europe in most cases (1p13, 1q41, and 9p21). Moreover, the seven risk variants identified in North Africans are efficient in discriminating between cases and controls in North African populations, but not in European populations. CONCLUSIONS: This study indicates a disparity in markers associated to CAD susceptibility between North Africans and Europeans that may be related to population differences in the chromosomal architecture of these risk regions.


Assuntos
Grupo com Ancestrais do Continente Africano/genética , Doença da Artéria Coronariana/etnologia , Doença da Artéria Coronariana/genética , Predisposição Genética para Doença/etnologia , Polimorfismo de Nucleotídeo Único/genética , Adulto , África do Norte , Grupo com Ancestrais do Continente Africano/estatística & dados numéricos , Idoso , Estudos de Casos e Controles , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 10/genética , Cromossomos Humanos Par 9/genética , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Genômica , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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