Micronucleus frequency in copper-mine workers exposed to arsenic is modulated by the AS3MT Met287Thr polymorphism.

Arsenic(III)methyltransferase (AS3MT) has been demonstrated to be the key enzyme in the metabolism of arsenic as it catalyses the methylation of arsenite and monomethylarsonic acid (MMA) to form methylated arsenic species, which have higher toxic and genotoxic potential than the parent compounds. The aim of this study is to evaluate if genetic variation in the AS3MT gene influences arsenic-induced cytogenetic damage, measured by the micronucleus (MN) assay. AS3MT Met287Thr allele frequencies and MN values were determined for 207 subjects working in the copper-mine industry, who were exposed to variable levels of arsenic.

Association between GSTO2 polymorphism and the urinary arsenic profile in copper industry workers.

Two members of the recently identified Omega class glutathione S-transferase enzymes (GSTO1 and GSTO2) have been proposed to play a role in the response to arsenic exposure. Therefore, polymorphisms in these genes could be related with variations in the arsenic excretion profile and, consequently, with the individual response to chronic exposure. Exons and flanking regions of GSTO2 gene have been screened in two different ethnic groups (20 Europeans and 20 Chilean Indians), and the urinary arsenic patterns and the GSTO2 Asn142Asp polymorphism have been investigated in 207 copper mine workers occupationally exposed to arsenic.

High arsenic metabolic efficiency in AS3MT287Thr allele carriers.

Objectives: Epidemiological data indicate the existence of wide interindividual differences in arsenic metabolism. It has recently been shown that arsenic(III)methyltransferase (AS3MT) enzyme catalyses the methylation of arsenite and monomethylarsonous acid (MMA). Thus, genetic variations in the AS3MT gene could explain, at least partly, the interindividual variation in the response to arsenic exposure.

Evaluation of micronucleus frequencies in blood lymphocytes from smelting plant workers exposed to arsenic.

Arsenic is a world health problem due to the seriousness of its effects, mainly related with the increase of cancer. In Chile, the geological characteristics of the northern region, associated with the development of the copper mining and smelting activities, have contributed to increase the environmental levels of arsenic. This study has been conducted to investigate the relationship between arsenic occupational exposure and genotoxic effects in smelting plant workers.

Role of the Met(287)Thr polymorphism in the AS3MT gene on the metabolic arsenic profile.

Chronic exposure to arsenic involves a biotransformation process leading to the excretion of methylated metabolites, such as monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), as well as the parental inorganic species (As(III) and As(V)). Inter-individual variations in arsenic biotransformation have been reported and polymorphisms affecting the genes involved in arsenic biotransformation have been considered as one of the plausible explanations for this variation. Coding and flanking regions of the human arsenic methyltransferase (AS3MT) gene have been analysed in 50 Chilean men exposed to arsenic.

Metabolic profile in workers occupationally exposed to arsenic: role of GST polymorphisms.

Arsenic is a well-known human carcinogen with a ubiquitous distribution in the natural environment. Chronic exposure to inorganic arsenic involves a biotransformation process that leds to the main excretion of organic methylated metabolites, such as monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), as well as the parental inorganic species. Interindividual variation in arsenic metabolism has been extensively reported, and polymorphisms in genes involved in such process could be related to changes in the arsenic excretion profile and the response to chronic exposures.

Sister chromatid exchange analysis in smelting plant workers exposed to arsenic.

There are many studies documenting the genotoxic effects of environmental exposure to arsenic. Nevertheless, few data are available on the genotoxic risks of occupational arsenic exposure. In the present study, we have evaluated whether or not occupational exposure to arsenic in a copper smelting plant results in a significant increase in the frequency of sister chromatid exchange (SCE).