MUTA PROP DNA ADDUCTS DERIV ESTROGENS & ANTIESTROGENS

描述：雌激素及其代谢物与 乳腺癌的病因学。 他莫昔芬是一种抗雌激素，用于 乳腺癌患者的治疗。 然而，他莫昔芬治疗 与子宫内膜癌有关，并已被证明会诱发 啮齿类动物的肝癌。 推动拟议研究的假设 假设雌激素和他莫昔芬对人类是弱致癌物， 反映了它们与 DNA 形成共价加合物的能力。 的目标 拟议的研究是确定选定的诱变潜力 他莫昔芬和雌激素 DNA 加合物。 寡脱氧核苷酸含有 单一定义的 DN 加合物将从活化形式的雌激素中制备 和他莫昔芬，或通过化学合成。 这些的错误编码属性 加合物将被量化。 要研究的特定加合物包括 鸟嘌呤 N2 位和 N6 位上的雌激素或他莫昔芬加合物 腺嘌呤的位置，并且这些加合物将使用各种生成 雌激素和他莫昔芬的不同活化代谢物。 使用哺乳动物 DNA 聚合酶、稳态动力学将用于测量频率 每个损伤对面的核苷酸插入和 3' 的链延伸 终点站。 通过这种方式，每个加合物的体外错误编码特异性 将成立。 错误编码属性将在下分析 稳态条件，使用具有不同加合物的模板 序列上下文，并使用三种不同的哺乳动物聚合酶。 网站 特异加合的寡核苷酸也将用于构建质粒，以便 在哺乳动物体内建立所选加合物的错误编码特异性 细胞。 所提出的实验旨在提供定量 有关选定雌激素和抗雌激素 DNA 的致突变性信息 加合物。 为体外实验制备的他莫昔芬 DNA 加合物将 也可用作研究中的标准标记来检测加合物 接受他莫昔芬治疗的患者的DNA；初步研究有 确定子宫内膜组织中存在此类加合物。 博士。 Shibutani将探索利用他莫昔芬检测的可能性 DNA 加合物作为生物标志物研究他莫昔芬之间的关系 子宫内膜癌的治疗和发展。

DESCRIPTION: Estrogens and their metabolites have been implicated in the etiology of breast cancer. Tamoxifen is an anti-estrogen that is used in the treatment of breast cancer patients. However, tamoxifen treatment has been associated with endometrial cancer, and has been shown to induce hepatocarcinoma in rodents. The hypothesis driving the proposed research postulates that estrogens and tamoxifen are weak carcinogens in humans, reflecting their ability to form covalent adducts with DNA. The goal of the proposed research is to establish the mutagenic potential of selected tamoxife and estrogen DNA adducts. Oligodeoxynucleotides containing a single defined DN adduct will be prepared from activated forms of estrogens and tamoxifen, or by chemical synthesis. The miscoding properties of these adducts will be quantified. The particular adducts to be studied include estrogen or tamoxifen adducts at the N2 position of Guanine and the N6 position of Adenine, and thes adducts will be generated using various different activated metabolites of estrogen and tamoxifen. Using mammalian DNA polymerases, steady state kinetics will be used to measure frequencies of nucleotide insertion opposite each lesion and chain extension from the 3' terminus. In this way the in vitro miscoding specificity for each adduct will be established. Miscoding propertie will be analyzed under steady-state conditions, using templates with the adducts in different sequence contexts, and using three different mammalian polymerases. Site specifically adducted oligos will also be used to build plasmids in order to establish the miscoding specificity of selected adducts i vivo, in mammalian cells. The proposed experiments are designed to provide quantitative information on the mutagenicity of selected estrogen and anti-estrogen DNA adducts. The tamoxifen DNA adducts prepared for in vitro experiments will also be employed for as standard markers in studies to detect adducts in the DNA of patients undergoing tamoxifen treatment; preliminary studies have established the presence of such adducts in endometrial tissue. Dr. Shibutani will explore the possibility of using the detection of tamoxifen DNA adducts as a biomarker to investigate the relationship between tamoxifen therapy and the development of endometrial cancer.