In humans, ingested inorganic arsenic is metabolized to monomethylarsenic (MMA) then to dimethylarsenic (DMA), although in most people this process is not complete. Previous studies have identified associations between the proportion of urinary MMA (%MMA) and increased risks of several arsenic-related diseases, although none of these reported on lung cancer. In this study, urinary arsenic metabolites were assessed in 45 lung cancer cases and 75 controls from arsenic-exposed areas in Cordoba, Argentina.
View Article and Find Full Text PDFJ Toxicol Environ Health A
January 2007
Methylation is the primary route of metabolism of inorganic arsenic in humans, and previous studies showed that interindividual differences in arsenic methylation may have important impacts on susceptibility to arsenic-induced cancer. To date, the factors that regulate arsenic methylation in humans are mostly unknown. Urinary arsenic methylation patterns and genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and glutathione S-transferase (GST) were investigated in 170 subjects from an arsenic-exposed region in Argentina.
View Article and Find Full Text PDFObjective: We sought to assess whether the metabolism of arsenic impacts a person's susceptibility to bladder cancer.
Methods: Urinary methylation products were measured in subjects from Argentina (114 cases and 114 controls) and the United States (23 cases and 49 controls).
Results: In Argentina, the adjusted odds ratio (OR) for subjects with a high proportion of ingested arsenic excreted as monomethylarsonate (%MMA) was 2.
Mate is a 'tea', made from Ilex paraguariensis, widely consumed in South America, as mate con bombilla and mate cocido. Mate consumption has been associated with esophageal, oral, lung, and bladder cancers. This bladder cancer case-control study involved 114 Argentinean case-control pairs.
View Article and Find Full Text PDFWe investigated the role of glutathione S-transferase (GST) enzymes (M1, T1), methylenetetrahydrofolate (MTHFR) 677 and 1298, and the NAD(P)H:quinone oxidoreductase (NQO1) polymorphisms in a population-based bladder cancer case-control study in Argentina. Buccal cell DNA was obtained from 106 cases and 109 controls. The strongest evidence was for an interaction between NQO1 genotype and smoking.
View Article and Find Full Text PDFStudies have found increased bladder cancer risks associated with high levels of arsenic in drinking water, but little information exists about risks at lower concentrations. Ecologic studies in Argentina have found increased bladder cancer mortality in Córdoba Province, where some wells are contaminated with moderate arsenic concentrations. This population-based bladder cancer case-control study in two Córdoba counties recruited 114 case-control pairs, matched on age, sex, and county, during 1996-2000.
View Article and Find Full Text PDFPrevious studies demonstrated that tobacco and arsenic exposure are risk factors for bladder cancer. A case-case study was conducted to compare p53 mutations in 147 bladder tumors from South American patients by tobacco and arsenic exposure. Information on residential history and lifestyle factors was collected.
View Article and Find Full Text PDFBackground: Previous studies have demonstrated that ingestion of arsenic in drinking water is a strong risk factor for several forms of cancer, including bladder cancer. It is not known whether arsenic-related cancers are genetically similar to cancers in unexposed individuals or what mechanisms of carcinogenesis may underlie their formation. This study was designed to compare chromosomal alterations in bladder cancers of arsenic-exposed individuals to provide insight into the mechanism of how arsenic may induce or promote cancer.
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