Les objectifs généraux du programme de recherche de l’UMR-946 sont :
Ce programme s'articule autour de 2 thématiques principales et complémentaires :
Au total, le programme de recherche de l' UMR-946 est conçu pour répondre aux nouveaux défis posés par les avancées sans cesse croissantes dans les technologies de génotypage et de séquençage et de la biologie à grande échelle afin de progresser vers une approche de biologie des systèmes des maladies.
Les objectifs de nos développements méthodologiques sont :
- de prendre en compte les mécanismes complexes impliqués dans les maladies multifactorielles :
interactions GènexGène, GènexEnvironnement, pléiotropie, hétérogénéité génétique…
- d’étendre les méthodes basées sur la consanguinité pour faciliter l’identification des gènes
- de permettre l’étude d'un large spectre de variabilité génétique
- d’intégrer les données de la biologie à grande échelle (génomique, transcriptomique, épigenomique,…)
Nos études de génétique épidémiologique sont principalement ciblées sur l'asthme, les maladies allergiques et les cancers. Ces études reposent sur de grandes collections de données que nous avons recueillies pour divers cancers (mélanome, cancer du poumon, cancer des voies aérodigestives supérieures, cancer de la vessie) ou auxquelles notre unité est étroitement associée (comme l’Etude épidémiologique des facteurs Génétiques et Environnementaux de l’asthme (EGEA). Ces études intègrent des études d'association pangénomique et des approches de biologie à grande échelle appliquées à de nombreux phénotypes associés aux maladies. Ces études sont menées dans un cadre pluridisciplinaire et dans un contexte de nombreuses collaborations nationales, européennes et internationales.
Les principaux objectifs de ces études sont :
- d’identifier de nouveaux gènes et des interactions gène-environnement impliqués dans ces maladies
- de mieux comprendre les mécanismes moléculaires qui sous-tendent le processus pathologique
- de traduire les résultats de la recherche en applications médicales
Date: 2 mai 2012 - 18:09
Desc: UNLABELLED: ABSTRACT: BACKGROUND: Transient receptor potential (TRP) vanilloid and ankyrin cation channels are activated by various noxious chemicals and may play an important role in the pathogenesis of cough. The aim was to study the influence of single nucleotide polymorphisms (SNPs) in TRP genes and irritant exposures on cough. METHODS: Nocturnal, usual, and chronic cough, smoking, and job history were obtained by questionnaire in 844 asthmatic and 2046 non-asthmatic adults from the Epidemiological study on the Genetics and Environment of Asthma (EGEA) and the European Community Respiratory Health Survey (ECRHS). Occupational exposures to vapors, gases, dusts, and/or fumes were assessed by a job-exposure matrix. Fifty-eight tagging SNPs in TRPV1, TRPV4, and TRPA1 were tested under an additive model. RESULTS: Statistically significant associations of 6 TRPV1 SNPs with cough symptoms were found in non-asthmatics after correction for multiple comparisons. Results were consistent across the eight countries examined. Haplotype-based association analysis confirmed the single SNP analyses for nocturnal cough (7-SNP haplotype: p-global = 4.8 × 10-6) and usual cough (9-SNP haplotype: p-global = 4.5 × 10-6). Cough symptoms were associated with exposure to irritants such as cigarette smoke and occupational exposures (p < 0.05). Four polymorphisms in TRPV1 further increased the risk of cough symptoms from irritant exposures in asthmatics and non-asthmatics (interaction p < 0.05). CONCLUSIONS: TRPV1 SNPs were associated with cough among subjects without asthma from two independent studies in eight European countries. TRPV1 SNPs may enhance susceptibility to cough in current smokers and in subjects with a history of workplace exposures.
Date: 23 oct 2012 - 18:28
Desc: BACKGROUND: Genome-wide association studies have identified determinants of chronic obstructive pulmonary disease, asthma, and lung function level; however, none have addressed decline in lung function. OBJECTIVE: We conducted the first genome-wide association study on the age-related decrease in FEV(1) and its ratio to forced vital capacity (FVC) stratified a priori by asthma status. METHODS: Discovery cohorts included adults of European ancestry (1,441 asthmatic and 2,677 nonasthmatic participants: the Epidemiological Study on the Genetics and Environment of Asthma, the Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults, and the European Community Respiratory Health Survey). The associations of FEV(1) and FEV(1)/FVC ratio decrease with 2.5 million single nucleotide polymorphisms (SNPs) were estimated. Thirty loci were followed up by in silico replication (1,160 asthmatic and 10,858 nonasthmatic participants: Atherosclerosis Risk in Communities, the Framingham Heart Study, the British 1958 Birth Cohort, and the Dutch Asthma Study). RESULTS: Main signals identified differed between asthmatic and nonasthmatic participants. None of the SNPs reached genome-wide significance. The association between the height-related gene DLEU7 and FEV(1) decrease suggested for nonasthmatic participants in the discovery phase was replicated (discovery, P = 4.8 × 10(-6); replication, P = .03), and additional sensitivity analyses point to a relation to growth. The top ranking signal, TUSC3, which is associated with FEV(1)/FVC ratio decrease in asthmatic participants (P = 5.3 × 10(-8)), did not replicate. SNPs previously associated with cross-sectional lung function were not prominently associated with decline. CONCLUSIONS: Genetic heterogeneity of lung function might be extensive. Our results suggest that genetic determinants of longitudinal and cross-sectional lung function differ and vary by asthma status.
Date: 22 aoû 2012 - 14:07
Desc: ABSTRACT: BACKGROUND: Structural variations such as copy number variants (CNV) influence the expression of different phenotypic traits. Algorithms to identify CNVs through SNP-array platforms are available. The ability to evaluate well-characterized CNVs such as GSTM1 (1p13.3) deletion provides an important opportunity to assess their performance. RESULTS: 773 cases and 759 controls from the SBC/EPICURO Study were genotyped in the GSTM1 region using TaqMan, Multiplex Ligation-dependent Probe Amplification (MLPA), and Illumina Infinium 1M SNP-array platforms. CNV callings provided by TaqMan and MLPA were highly concordant and replicated the association between GSTM1 and bladder cancer. This was not the case when CNVs were called using Illumina 1M data through available algorithms since no deletion was detected across the study samples. In contrast, when the Log R Ratio (LRR) was used as a continuous measure for the 5 probes contained in this locus, we were able to detect their association with bladder cancer using simple regression models or more sophisticated methods such as the ones implemented in the CNVtools package. CONCLUSIONS: This study highlights an important limitation in the CNV calling from SNP-array data in regions of common aberrations and suggests that there may be added advantage for using LRR as a continuous measure in association tests rather than relying on calling algorithms.
Date: 20 fév 2019 - 12:18
Desc: [...]
Date: 20 juil 2012 - 10:49
Desc: So far, no common environmental and/or phenotypic factor has been associated with melanoma and renal cell carcinoma (RCC). The known risk factors for melanoma include sun exposure, pigmentation and nevus phenotypes; risk factors associated with RCC include smoking, obesity and hypertension. A recent study of coexisting melanoma and RCC in the same patients supports a genetic predisposition underlying the association between these two cancers. The microphthalmia-associated transcription factor (MITF) has been proposed to act as a melanoma oncogene; it also stimulates the transcription of hypoxia inducible factor (HIF1A), the pathway of which is targeted by kidney cancer susceptibility genes. We therefore proposed that MITF might have a role in conferring a genetic predisposition to co-occurring melanoma and RCC. Here we identify a germline missense substitution in MITF (Mi-E318K) that occurred at a significantly higher frequency in genetically enriched patients affected with melanoma, RCC or both cancers, when compared with controls. Overall, Mi-E318K carriers had a higher than fivefold increased risk of developing melanoma, RCC or both cancers. Codon 318 is located in a small-ubiquitin-like modifier (SUMO) consensus site (ΨKXE) and Mi-E318K severely impaired SUMOylation of MITF. Mi-E318K enhanced MITF protein binding to the HIF1A promoter and increased its transcriptional activity compared to wild-type MITF. Further, we observed a global increase in Mi-E318K-occupied loci. In an RCC cell line, gene expression profiling identified a Mi-E318K signature related to cell growth, proliferation and inflammation. Lastly, the mutant protein enhanced melanocytic and renal cell clonogenicity, migration and invasion, consistent with a gain-of-function role in tumorigenesis. Our data provide insights into the link between SUMOylation, transcription and cancer.
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