Novel Bioconjugates as Probes of Estrogen Receptors

说明(申请人提供)：基于雌激素的药物被广泛用于从乳腺癌到更年期到避孕的治疗领域，但由于药物在其他组织中的不良影响，所有这些药物都受到限制。这项拟议研究的长期目标是在细胞内其他信号通路的背景下阐明雌激素信号的分子细节，以及这些信号通路的串扰如何决定雌激素类药物的反应曲线。越来越多的证据表明，类固醇激素可以引发位于核外的受体的反应。这些反应的可能受体是所有类固醇激素的受体，从新型跨膜受体到位于内质网的G蛋白偶联受体，再到不同形式的经典类固醇激素受体。我们假设，将雌激素配体定位于细胞的某些部分可以选择性地调节其中一些反应。我们建议对不同类型的雌激素调节反应进行几项不同的研究，重点是配体结构和受体定位如何在调节不同类型的雌激素和抗雌激素化合物的反应中发挥作用。目的1致力于合成定位于细胞不同部位的不同雌激素类似物的新型大分子偶联物。我们发现，4-羟基三苯氧胺偶联到不同的支架上，可以定位于细胞核、细胞质或外质膜。是否其他雌激素配体可以引起相同的定位模式将被探索。目的2主要研究配体的结构和定位如何影响多种不同的雌激素反应。我们以前的结果支持这样的假设，即许多依赖串扰的反应背后的结构-活性关系与经典雌激素受体活性的基础显著不同，Aim 2将专注于观察对雌激素的多种不同反应，以及配体对细胞某些部分的定位是否也起到作用。在目标3中，我们建议调查偶联物本身的性质是否对它们的一些生物效应负责，并探索多价性和共轭化学的可能影响。目标4将研究结合物对不同雌激素受体的功能作用，以及对雌激素和抗雌激素化合物的一些细胞反应。

DESCRIPTION (provided by applicant): Estrogen-based drugs are used widely for treatment areas ranging from breast cancer to menopause to contraception, but all of them suffer limitations due to unwanted effects of the drugs in other tissues. The long-term goal of this proposed research is to elucidate the molecular details of estrogen signaling in the context of other signaling pathways in the cell and how crosstalk with these signaling pathways dictate the response profiles of estrogen-mimicking drugs. Growing evidence suggests that steroid hormones can elicit responses from receptors located outside of the nucleus. Possible receptors for these responses, which have been noted for all steroid hormones, range from novel classes of membrane-spanning receptors to G-protein coupled receptors located on endoplasmic reticulum to different forms of the classic steroid hormone receptor. We hypothesize that targeting estrogen ligands to certain parts of the cell could selectively modulate some of these responses. We propose to carry out several different studies of different types of estrogen-regulated responses focusing on how ligand structure and receptor localization play a role in modulating different types of responses to estrogenic and antiestrogenic compounds. Aim 1 is focused on the synthesis of novel macromolecular conjugates of different estrogen-mimicking analogs that localize to different parts of the cell. We have found that 4-hydroxytamoxifen conjugated to different scaffolds can localize to the nucleus, cytoplasm, or outer plasma membrane. Whether other estrogen ligands can elicit the same pattern of localization will be explored. Aim 2 is focused on investigating how ligand structure and localization affects a number of different estrogen responses. Our previous results support the hypothesis that the structure-activity relationships underlying many of these crosstalk-dependent responses are significantly different than those underlying classic estrogen receptor activity, and Aim 2 will focus on assays looking at a number of diverse responses to estrogen and whether localization of the ligand to certain parts of the cell can also play a role. In aim 3, we propose to investigate whether the properties of the conjugates themselves are responsible for some of their biological effects and explore possible effects of multivalency and conjugation chemistry. Aim 4 will look at the functional actions of the conjugates on the different estrogen receptors and on a number of cellular responses to estrogenic and antiestrogenic compounds.