Development and Characterization of Novel SERMs

这项研究的目的是确定激素依赖组织和癌症中雌激素激动剂和拮抗剂之间的分子差异，并开发和表征具有组织选择性雌激素或抗雌激素特性的新化合物。由于这些效应是由两种已知的哺乳动物雌激素受体ERα和ERβ中的一种或两种介导的，因此了解受体-配体复合体的差异诱导的构象变化和分析新型受体配体的行为特征对于开发选择性雌激素受体调节剂(SERM)是至关重要的。因此，该项目的一个主要目标是将化合物在体外和体内的行为与与新的甾体和非甾体SERM络合的ERa和ERbeta的晶体结构联系起来。这些信息将被用来帮助修改或设计具有可预测的、改变的药理特性的化合物。为了实现这些目标，我们将：1)确定与已知和/或新合成的具有独特组织选择性和受体选择性特性的SERM复合的ERpha和ERbeta LBD的详细晶体结构。结构信息将与诱变分析一起使用，以确定配体结合口袋内的重要接触，并修改和/或设计具有改变的药理性质的配体。2)在体外和体内激素敏感的动物肿瘤模型(包括裸鼠异种移植瘤和大鼠乳腺肿瘤模型)中鉴定新的ERα和/或ERβ选择性配体。为了确定潜在的治疗效果，我们将通过测量子宫营养反应、胆固醇水平和骨密度来研究候选配体在大鼠和小鼠身上的体内药理学。这一行为将与瞬时和稳定转染细胞中雌激素反应启动子的报告分析中两种ER的活性进行比较。预计在配体设计中利用ER亚型特异性相互作用将允许创建对两种ER起不同作用并具有新的治疗特性的新化合物。此外，随着选择性靶向ERa或ERbeta的化合物的设计和/或自然发生，结构信息应该有助于揭示这种行为的分子基础。

The objective of this investigation is to determine the molecular distinctions between estrogen agonism and antagonism in hormone dependent tissues and cancers and to develop and characterize novel compounds that have desired tissue-selective estrogenic or antiestrogenic properties. Because these effects are mediated by one or both of two known mammalian estrogen receptors, ERalpha and ERbeta, knowledge of the differentially induced conformational changes of receptor-ligand complexes and analysis of behavior profiles for novel receptor ligands is essential for developing selective estrogen receptor modulators (SERMs). Therefore, a major goal of this project is to correlate compound behavior in vitro and in vivo with the crystallographic structures of ERalpha and ERbeta complexed with novel steroidal and nonsteroidal SERMs. This information will be used to help modify or design compounds with predictable, altered pharmacological properties. To accomplish these goals we will: 1) Determine the detailed crystallographic structures of ERalpha and ERbeta LBDs complexed with known and/or newly synthesized SERMs with unique tissue-selective and receptor-selective properties. Structure information will be used in conjunction with mutagenic analyses to define important contacts within the ligand binding pocket and to modify and/or design ligands with altered pharmacological properties. 2) Characterize novel ERalpha and/or ERbeta-selective ligands in in vitro and in hormone sensitive in vivo animal tumor models, including athymic mouse xenografts and rat mammary tumor models. To determine potential therapeutic utility, we will study the in vivo pharmacology of candidate ligands in rats and mice by measuring utertrophic response, cholesterol levels, and bone density. This behavior will be compared with the activities of both ERs in reporter assays of estrogen responsive promoters in both transiently and stably transfected cells. It is anticipated that the utilization of ER subtype-specific interactions in ligand design will allow the creation of new compounds that act differently on the two ERs and possess novel therapeutic properties. In addition, with the design and/or natural occurrence of compounds that selectively target ERalpha or ERbeta, structure information should help reveal the molecular basis for such behavior.