Bonassi S.,Unit of Clinical and Molecular Epidemiology IRCCS San Raffaele Pisana |
Coskun E.,Unit of Clinical and Molecular Epidemiology IRCCS San Raffaele Pisana |
Coskun E.,Gazi University |
Ceppi M.,Italian National Cancer Institute |
And 34 more authors.
Mutation Research - Reviews in Mutation Research
The human buccal micronucleus cytome assay (BMCyt) is one of the most widely used techniques to measure genetic damage in human population studies. Reducing protocol variability, assessing the role of confounders, and estimating a range of reference values are research priorities that will be addressed by the HUMN XL collaborative study. The HUMN XL project evaluates the impact of host factors, occupation, life-style, disease status, and protocol features on the occurrence of MN in exfoliated buccal cells. In addition, the study will provide a range of reference values for all cytome endpoints. A database of 5424 subjects with buccal MN values obtained from 30 laboratories worldwide was compiled and analyzed to investigate the influence of several conditions affecting MN frequency. Random effects models were mostly used to investigate MN predictors. The estimated spontaneous MN frequency was 0.74‰ (95% CI 0.52-1.05). Only staining among technical features influenced MN frequency, with an abnormal increase for non-DNA-specific stains. No effect of gender was evident, while the trend for age was highly significant (p<0.001). Most occupational exposures and a diagnosis of cancer significantly increased MN and other endpoints frequencies. MN frequency increased in heavy smoking (≥40cig/day, FR=1.37; 95% CI 1.03-82) and decreased with daily fruit consumption (FR=0.68; 95% CI 0.50-0.91). The results of the HUMN XL project identified priorities for validation studies, increased the basic knowledge of the assay, and contributed to the creation of a laboratory network which in perspective may allow the evaluation of disease risk associated with MN frequency. © 2011 Elsevier B.V. Source
Cadby G.,University of Western Australia |
Mukherjee S.,Womens College Hospital and Research Institute |
Mukherjee S.,Kings College |
Musk A.W.,Sir Charles Gairdner Hospital |
And 30 more authors.
Malignant mesothelioma (MM) is a uniformly fatal tumour of mesothelial cells. MM is caused by exposure to asbestos however most individuals with documented asbestos exposure do not develop MM. Although MM appears to aggregate within families, the genetics of MM susceptibility is a relatively unexplored area. The aim of the current study was to identify genetic factors that contribute to MM risk. A genome-wide association analysis of 2,508,203 single nucleotide polymorphisms (SNPs) from 428 MM cases and 1269 controls from Western Australia was performed. Additional genotyping was performed on a sample of 778 asbestos-exposed Western Australian controls. Replication of the most strongly associated SNPs was undertaken in an independent case-control study of 392 asbestos-exposed cases and 367 asbestos-exposed controls from Italy. No SNPs achieved formal genome-wide statistical significance in the Western Australian study. However, suggestive results for MM risk were identified in the SDK1, CRTAM and RASGRF2 genes, and in the 2p12 chromosomal region. These findings were not replicated in the Italian study, although there was some evidence of replication in the region of SDK1. These suggestive associations will be further investigated in sequencing and functional studies. © 2013. Source
Matullo G.,Human Genetics Foundation |
Matullo G.,University of Turin |
Guarrera S.,Human Genetics Foundation |
Betti M.,University of Piemonte Orientale |
And 49 more authors.
Asbestos exposure is the main risk factor for malignant pleural mesothelioma (MPM), a rare aggressive tumor. Nevertheless, only 5-17% of those exposed to asbestos develop MPM, suggesting the involvement of other environmental and genetic risk factors.To identify the genetic risk factors that may contribute to the development of MPM, we conducted a genome-wide association study (GWAS; 370,000 genotyped SNPs, 5 million imputed SNPs) in Italy, among 407 MPM cases and 389 controls with a complete history of asbestos exposure. A replication study was also undertaken and included 428 MPM cases and 1269 controls from Australia.Although no single marker reached the genome-wide significance threshold, several associations were supported by haplotype-, chromosomal region-, gene- and gene-ontology process-based analyses. Most of these SNPs were located in regions reported to harbor aberrant alterations in mesothelioma (SLC7A14, THRB, CEBP350, ADAMTS2, ETV1, PVT1 and MMP14 genes), causing at most a 2-3-fold increase in MPM risk. The Australian replication study showed significant associations in five of these chromosomal regions (3q26.2, 4q32.1, 7p22.2, 14q11.2, 15q14).Multivariate analysis suggested an independent contribution of 10 genetic variants, with an Area Under the ROC Curve (AUC) of 0.76 when only exposure and covariates were included in the model, and of 0.86 when the genetic component was also included, with a substantial increase of asbestos exposure risk estimation (odds ratio, OR: 45.28, 95% confidence interval, CI: 21.52-95.28).These results showed that genetic risk factors may play an additional role in the development of MPM, and that these should be taken into account to better estimate individual MPM risk in individuals who have been exposed to asbestos. © 2013 Matullo et al. Source