ESTROGEN/DNA ADDUCT ANALYSIS IN URINE

除了主要的内源性雌激素外，特定的雌激素代谢物(包括16 α (OH)雌酮、4-（OH)雌酮和4-(OH)雌二醇）被认为对人类具有遗传毒性和潜在致癌性。这些雌激素代谢物被认为发挥其致癌作用的一种机制是形成亲电醌产物，这些产物与DNA反应形成去嘌呤加合物，已知在体外和体内研究中产生引发癌症的突变。尽管内源性雌激素代谢物和DNA加合物的形成在乳腺癌发生过程中具有潜在的重要性，但尚未有研究调查它们与人类乳腺癌风险的关系。这种数据的缺乏部分是由于缺乏一种分析人体生物体液中雌激素- dna加合物的方法。开发一种廉价、快速的方法将使流行病学研究能够确定特定雌激素DNA加合物与乳腺癌风险之间的关系，以及这些化合物与肥胖和饮食等可改变的风险因素之间的关系。本项目的主要目的是建立一种快速、特异、灵敏的内源性雌激素代谢产物dna加合物分析方法，为大规模流行病学研究提供实用的方法。本项目的具体目的是开发和验证一种HPLC-ESI-MS/MS方法，用于分析尿液雌激素DNA加合物，如4(OH)-E1 (E2)-1 (α, β)- n7鸟嘌呤。将分析月经周期中卵泡中期和黄体中期以及绝经后妇女的尿液，以确定质量控制参数。这种方法的发展将使我们能够对雌激素代谢、DNA加合物和乳腺癌进行大规模流行病学研究，这将有助于我们了解雌激素影响乳腺癌风险的机制。

In addition to the major endogenous estrogens, specific estrogen metabolites (including 16alpha(OH) estrone, 4-(OH) estrone, and 4-(OH) estradiol) are thought to be genotoxic and potentially carcinogenic in humans. One mechanism by which these estrogen metabolites are thought to exert their carcinogenic effects is the formation of electrophilic quinone products that react with DNA to form depurinating adducts known to generate mutations that initiate cancer in both in vitro and in vivo studies. Despite the potential importance of endogenous estrogen metabolites and DNA adduct formation in breast carcinogenesis, no studies have investigated their association with human breast cancer risk. This lack of data is due in part to the lack of a method of analysis for estrogen-DNA adducts in human biological fluids. Development of an inexpensive, rapid method will enable the performance of epidemiologic studies that determine the associations between specific estrogen DNA adducts and breast cancer risk, as well as the associations between these compounds and modifiable risk factors such as obesity and diet. The main purpose of this project is to develop a rapid, specific, and sensitive method of analysis of endogenous estrogen metabolite-DNA adducts, that will be practical for use in large epidemiological studies. The specific aims of this project are to develop and validate an HPLC-ESI-MS/MS method for analysis of urinary estrogen DNA adducts, such as 4(OH)-E1 (E2)-1 (alpha,beta)-N7Guanine. Urine from the midfollicular and midluteal phases of the menstrual cycle, as well as from postmenopausal women, will be analyzed for determination of quality control parameters. The development of this method will enable the performance of large epidemiological studies of estrogen metabolism, DNA adducts, and breast cancer, that will contribute to our understanding of the mechanisms by which estrogen influences breast cancer risk.