MUTA PROP DNA ADDUCTS DERIV ESTROGENS & ANTIESTROGENS

描述：雌激素及其代谢物被认为与 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，他莫昔芬治疗已经 与子宫内膜癌有关，并已被证明会诱发 啮齿动物的肝癌。推动这项研究的假设 假设雌激素和他莫昔芬在人类中是微弱的致癌物， 反映了它们与DNA形成共价加合物的能力。的目标是 建议的研究是建立选定的突变潜力 三苯氧胺和雌激素DNA加合物。含有A的寡聚脱氧核苷酸 单一限定的DN加合物将由活化形式的雌激素制备 和他莫昔芬，或通过化学合成。这些代码的错误编码属性 加合物将被量化。需要研究的特殊加合物包括 雌激素或他莫昔芬在鸟嘌呤和N6的N_2位的加合物 腺嘌呤的位置，这些加合物将使用各种不同的 雌激素和三苯氧胺的不同活性代谢物。使用哺乳动物 DNA聚合酶，将使用稳态动力学来测量频率 与每个损伤相对的核苷酸插入和从3‘端延伸的链 终点站。通过这种方式，每个加合物的体外错误编码特异性 将会建立起来。错误编码属性将在以下内容中分析 稳态条件，使用模板和不同的加合物 序列背景，并使用三种不同的哺乳动物聚合酶。立地 具体地说，加成的寡核苷酸也将被用来构建质粒，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。拟议的实验旨在提供定量的 部分雌激素和抗雌激素DNA的致突变性研究进展 加合物。用于体外实验的三苯氧胺DNA加合物将 也可用作研究中的标准标记，以检测加合物 接受三苯氧胺治疗的患者的DNA；初步研究 证实了子宫内膜组织中存在这样的加合物。Dr。 涉谷将探索使用三苯氧胺检测的可能性 DNA加合物作为生物标志物研究三苯氧胺的关系 治疗与子宫内膜癌的发展。

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.