Novel Bioconjugates as Probes of Estrogen Receptors

描述（由申请人提供）：基于雌激素的药物广泛用于从乳腺癌到更年期到避孕等治疗领域，但由于药物对其他组织的不良影响，所有这些药物都受到限制。本研究的长期目标是阐明细胞中其他信号通路中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模拟药物的反应谱。越来越多的证据表明，类固醇激素可以引起核外受体的反应。这些反应的可能受体，已经在所有类固醇激素中被注意到，范围从新型的跨膜受体到内质网上的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靶向到细胞的某些部位可以选择性地调节其中的一些反应。我们建议开展几种不同类型的雌激素调节反应的不同研究，重点关注配体结构和受体定位如何在调节雌激素和抗雌激素化合物的不同类型反应中发挥作用。Aim 1的重点是合成不同雌激素模拟类似物的新型大分子偶联物，这些类似物定位于细胞的不同部位。我们发现4-羟他莫昔芬缀合到不同的支架可以定位到细胞核、细胞质或外质膜。其他雌激素配体是否也能引起相同的定位模式有待进一步研究。目的2是研究配体结构和定位如何影响许多不同的雌激素反应。我们之前的研究结果支持了这样的假设，即许多依赖于串扰的反应背后的结构-活性关系与经典雌激素受体活性背后的结构-活性关系有显著不同，Aim 2将重点关注对雌激素的多种反应的分析，以及配体在细胞某些部位的定位是否也起作用。在目标3中，我们建议研究共轭物本身的性质是否对它们的一些生物效应负责，并探索多价和共轭化学的可能影响。目的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.