POLYAMINES AND ESTROGEN FUNCTION AND BREAST CANCER

描述：(申请人摘要)本申请的总体目标 是研究多胺在雌激素调节中的作用 乳腺癌细胞的增殖。此前的研究表明， 多胺改变雌激素受体与雌激素的结合 响应要素(ERE)。最近的研究描述了多胺 在ERE序列中产生B*DNA的诱导DNA构象变化 这反过来又促进了ER/ERE复合体的形成。结果是 提示多胺在雌激素的作用中起重要作用 细胞周期动力学和调节细胞周期的蛋白质，如 细胞周期蛋白D1。需要检验的主要假设是多胺有一个 乳腺癌细胞通过其调节细胞生长的能力发挥作用 调节ER/ERE结合，改变功能细胞周期机制。 目的是验证这一假说，并在治疗方面取得进展 活化剂，多胺在ER/ERE相互作用中的作用将是 使用：(I)圆二向色性光谱来确定ERE 必须满足的序列和多胺结构要求 对于B*构象的诱导，(Ii)电泳迁移率 移位分析和竞争性ER/ERE结合分析 多胺及其类似物对内质网/ERE复合体形成的影响 以及(Iii)DNA足迹分析以定位多胺诱导的 内质网结合部位的构象变化。调制的功效 ER/ERE结合将被用作确定治疗方法的第一个测试 一类新的环多胺的潜力。选定的类似物将是 研究它们对以下方面的影响：(I)增殖和细胞周期 动力学，(Ii)细胞多胺水平和多胺的调节 代谢酶，以及(Iii)体内多胺转运的变化。 雌激素敏感型乳腺癌细胞系MCF-7。它的作用机制 多胺类似物在改变细胞周期动力学中的作用将被考察。 以细胞周期蛋白D1mRNA和蛋白的调控为靶点。 多胺类似物与细胞周期蛋白D1之间的相互作用将进一步 在MCF-7细胞中高表达细胞周期蛋白D1。小说方面 雌激素相关蛋白的雌激素信号转导将 通过多胺类似物和雌激素的特性进行检测- 这些蛋白质的响应性及其在细胞中作用的确定 成长。这些研究的结果将为我们对 多胺在乳腺癌雌激素作用中的作用机制 并为新疗法的鉴定和设计做出了贡献 探员们。

DESCRIPTION: (Applicant's Abstract) The overall goal of this application is to investigate the role of polyamines in the estrogenic regulation of breast cancer cell proliferation. Previous studies demonstrated that polyamines alter the binding of estrogen receptor (ER) to estrogen response elements (ERE). Recent studies have described the polyamine induced DNA conformational changes producing B* DNA in the ERE sequences which in turn facilitate the formation of ER/ERE complexes. The results suggest that polyamines play an important role in estrogen action on cell cycle kinetics and the regulation cell cycle proteins, such as cyclin D1. The main hypothesis to be tested is that polyamines have a regulatory role in breast cancer cell growth through their ability to modulate ER/ERE binding and alter the function cell cycle machinery. With the goals of testing this hypothesis and developing therapeutically active agents, the role of polyamines in ER/ERE interactions will be examined using: (i) circular dichroism spectroscopy to determine the ERE sequence and polyamine structural requirements which must be satisfied for the induction of B* conformation, (ii) electrophoretic mobility shift assays and competitive ER/ERE binding assays to quantify the effects of polyamine and polyamine analogue on ER/ERE-complex formation, and (iii) DNA-footprint analysis to localize the polyamine-induced conformational changes at the ER binding site. Efficacy in modulation ER/ERE binding will be used as a first test to identify the therapeutic potential of a new class of cyclopolyamines. Selected analogues will be investigated for their effects on: (i) proliferation and cell cycle kinetics, (ii) cellular polyamine levels and regulation of polyamine metabolic enzymes, and (iii) alteration in polyamine transport in the estrogen responsive breast cancer line, MCF-7. The mechanism of polyamine analogues in altering cell cycle kinetics will be examined using the regulation of cyclin D1 mRNA and protein as targets. Interactions between polyamine analogues and cyclin D1 will be further investigated in MCF-7 cells over-expressing cyclin D1. Novel aspects of estrogenic signal transduction through ER-associated proteins will be examined by characterization of polyamine analogue and estrogen- responsiveness of these proteins and determination of their role in cell growth. Results of these studies will provide new insights into the mechanism of action of polyamines in estrogen function in breast cancer and contribute to the identification and design of novel therapeutic agents.