Re: "Associations between breast cancer risk and the catalase genotype, fruit and vegetable consumption, and supplement use".
Re: "Associations between breast cancer risk and the catalase genotype, fruit and vegetable consumption, and supplement use".
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回复：“乳腺癌风险与过氧化氢酶基因型、水果和蔬菜消费以及补充剂使用之间的关联”。
DOI：
10.1093/aje/kwj131
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发表时间：
2006
影响因子：
5
通讯作者：
Kauffmann,Francine
中科院分区：
文献类型：
--
作者：
Nadif,Rachel;Kleeberger,StevenR;Kauffmann,Francine
Ahn et al.(1) observed that the CC genotype was associated with higher catalase activity in 18 subjects—a result at variance with the lower protein level observed by Forsberg et al.(2) in 29 subjects—and concluded that larger genotypephenotype association studies are required. We recently conducted such a study in a sample of 196 coal miners in France (3). The highest red blood cell catalase activity was observed in coal miners with the CAT ÿ262 CC genotype; miners with the TT genotype had a loss of activity of 31 percent (3). Our results extend those of Ahn et al.(1) with another method of measurement, and we also showed that persons who were heterozygous for the T allele had intermediate activity. Regarding gene 3 environment interactions, the study by Ahn et al.(1) and our study (3) provide convergent results. In both studies, the effect of factors previously found to be protective was enhanced only in subjects with the CC genotype (ie, persons with genetically high catalase activity). In the Long Island Breast Cancer Study Project (1), significantly lower risk was observed among women with high fruit and/or vegetable intake—an antioxidant-rich dietary environment—and this effect was enhanced in CAT ÿ262 CC carriers. In our study, miners carrying the NcoI B1 allele in the lymphotoxin o gene (ie, persons with a low level of circulating proinflammatory cytokine (4)) were found to be at lower risk of pneumoconiosis (5), considering disease prevalence and computed tomography score, a subclinical marker of the disease. After stratifying subjects according to the CAT ÿ262 polymorphism, we observed that this effect was enhanced in CAT ÿ262 CC carriers (for both 4-year change in computed tomography score and pneumoconiosis prevalence at the end of follow-up, p for interaction ¼ 0.01). Regardless of the disease, both studies showed that the effects of other factors studied seemed to be beneficial only in subjects with the CAT ÿ262 CC genotype. Among CAT ÿ262 T carriers (ie, persons with genetically low catalase activity), exposure to coal dust, the primary risk factor for pneumoconiosis and a constituent of an oxidant-rich environment, further decreased catalase activity (3). Moreover, CAT ÿ262 T carriers were found less frequently among highly exposed miners than among others (odds ratio ¼ 0.39, 95 percent confidence interval: 0.20, 0.78); this observation needs confirmation but is consistent with a healthy worker effect related to deleterious consequences of low catalase activity. Judging from the data presented by Ahn et al.(1), no association was observed between environment and genotype, but in that case the environment studied was a protective one.It is possible that the CAT ÿ262 polymorphism plays an important role in numerous oxidant-related diseases and it has not been studied in large epidemiologic surveys until now. Because it investigated associations with the genotype controlling the activity of a relevant enzyme, the study by Ahn et al.(1) presents a methodological advantage which has been described as Mendelian randomization (6), since it may control for unmeasured confounders. Indeed, considering CAT ÿ262 genotype or classes based on catalase activity
