Partial Agonists at Estrogen Receptor alpha for Breast Cancer Therapy

用于乳腺癌治疗的雌激素受体α部分激动剂

• 批准号: 9251781
• 负责人: Gregory R. J Thatcher
• 金额: $ 47.43万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-06 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9251781
• 关键词: Adverse effects; Affinity; Agonist; Androgen Receptor; Animal Model; Animals; Apoptosis; Benchmarking; Binding; Biological Assay; Biological Availability; Breast; Breast Cancer Cell; Breast Cancer Treatment; Breast Cancer therapy; Breast Epithelial Cells; Cell Line; Cell Survival; Cells; Chemicals; Chemistry; Chemoprevention; Clinical; Collection; Computer-Aided Design; Computing Methodologies; Data; Data Correlations; Development; Diethylstilbestrol; Drug Targeting; Endometrial; Endometrial Carcinoma; Endometrium; Estradiol; Estrogen Antagonists; Estrogen Receptor Modulators; Estrogen Receptor Status; Estrogen Receptor alpha; Estrogen Receptor beta; Estrogen Receptors; Estrogens; Europe; Exposure to; Female; Fluorescence Resonance Energy Transfer; Future; Generations; Genes; Growth; Gynecology; Human; In Vitro; Indoles; Lead; Libraries; Ligand Binding Domain; Ligands; Link; Liver Microsomes; MCF7 cell; MDA MB 231; Malignant Neoplasms; Mammary Gland Parenchyma; Mammary Neoplasms; Mammary gland; Measurement; Measures; Messenger RNA; Metabolism; NCOA3 gene; Oral; PRKCA gene; Parents; Patients; Pharmaceutical Preparations; Pharmacology; Phenotype; Plasma; Postmenopausal Osteoporosis; Progesterone Receptors; Proteins; Proteomics; Pyrazoles; Raloxifene; Reporter; Resistance; Resistance development; Risk; Safety; Selective Estrogen Receptor Modulators; Structure; T47D; TFF1 gene; Tamoxifen; Testing; Therapeutic; Therapeutic Agents; Therapeutic Index; Tissues; Transcription Factor AP-1; Uterus; Validation; Woman; Women' s Health; Xenograft Model; Xenograft procedure; base; benzothiophene; bone; cancer risk; chemotherapy; counterscreen; design; drug development; drug metabolism; effective therapy; epidemiology study; estrogenic; exhaustion; experience; improved; in vivo; in vivo Model; iterative design; lead series; malignant breast neoplasm; mortality; neglect; novel; novel therapeutics; oncology; outcome forecast; overexpression; personalized medicine; prototype; public health relevance; radioligand; receptor; receptor function; response; scaffold; screening; small molecule; standard of care; success; survivin; three dimensional cell culture; tumor; tumor growth

 DESCRIPTION (provided by applicant): The estrogen receptor (ER) is a drug target that has been exploited clinically by selective estrogen receptor modulators (SERMs) that antagonize estrogenic effects in breast tissue and act as agonists in bone. The proto- type of the SERM drug class, tamoxifen (TAM) has for 3 decades been the standard of care in breast cancer therapy, although agonist activity in the uterus increases risk of endometrial cancer. Conversely, the therapeutic potential of ERa agonists has not been explored or exploited. Up to 80% of breast cancers are ER+, in which estradiol (E2) fuels tumor growth. Of these, 30-50% are unresponsive to TAM or develop resistance, leaving few treatment options. Paradoxically, prior to the introduction of TAM, both E2 and the ER agonist diethylstilbestrol achieved success in the treatment of breast cancer, but with unacceptable side effects, including agonist activity in breast and uterus. A partial agonist at ERa without estrogenic actions in normal gynecological tissues, but with the ability to regress TAM-resistant cancers is a compelling concept, validated by us in 2 animal models with 2 small molecules. The assembled team at UI, Greg Thatcher, John Katzenellenbogen, Terry Moore, and Deb Tonetti has all assays and chemistry in place to achieve the proposed aims: Aim 1. A library of ~350 com- pounds consisting of 4 lead series will be completed and screened using a FRET assay for SRC3 co-activator binding to ERa and ERß. The ER interaction with co-activator is seen as the minimal predictor of phenotype. Radioligand displacement for ER represents a secondary, confirmatory assay. Partial agonists at ERa with agonist/inactive responses at ERß will be obtained and iteratively optimized using data from Aim 2 to provide SAR development for computer-aided design. Aim 2. Selected ERa agonists from FRET screening will be studied using reporter assays in endogenous ERa (MCF-7; T47D) and in ERß (ß43) mammary epithelial cells and endometrial cells to reveal potency, and agonist/antagonist pharmacology. Partial agonists will be further studied using PCR measurement of ERE, AP-1, and Sp1-sensitive genes. The primary phenotypic assay is apoptosis of TAM-resistant MCF7-5C cells. Counterscreens are proliferation of parent MCF7-5C and T47D cell lines. Aim 3. Drug metabolism in liver microsomes, multiplex CYP-inhibition, and oral plasma bioavailability will be used to refine ERa partial agonists as chemical probes. Our extensive experience with SERM metabolism and use of oral delivery in all preliminary data gives confidence in this approach. DMPK studies will provide final selection for animal studies. Three different TAM-resistant xenograft models will be used to test chemical probes and to determine therapeutic index for tumor regression. Safety will be predicted by uterine growth and parallel study of growth of estrogen-dependent T47D xenografts. Supportive mechanism of action studies are limited to ERa localization and target selectivity proteomics. Completion of these Aims will provide chemical probes to study the potential of novel partial agonists and allosteric modulators of ER function, and provide lead compounds for future testing in patient-derived xenografts of PKCa-overexpressing tumors as a prelude to drug development.

 说明(申请人提供)：雌激素受体(ER)是一种药物靶点，已被选择性雌激素受体调节剂(SERM)临床利用，该调节剂可在乳房组织中拮抗雌激素效应，并在骨骼中发挥激动剂的作用。三十年来，SERM药物的原型三苯氧胺()一直是乳腺癌治疗的标准治疗药物，尽管子宫中的激动剂活性会增加患子宫内膜癌的风险。相反，ERA激动剂的治疗潜力还没有被探索或开发。高达80%的乳腺癌是ER阳性的，其中雌二醇(E2)促进了肿瘤的生长。在这些人中，30%到50%对没有反应或产生抗药性，几乎没有治疗选择。矛盾的是，在被引入之前，E2和ER激动剂己烯雌酚在治疗乳腺癌方面都取得了成功，但都有不可接受的副作用，包括乳腺和子宫中的激动剂活性。部分激动剂在正常妇科组织中没有雌激素样作用，但具有逆转耐药癌症的能力，这是一个引人注目的概念，我们用两个小分子在两个动物模型中验证了这一概念。在UI、Greg Thatcher、John Katzenellenbogen、Terry Moore和Deb Tonetti组建的团队已经准备好了所有的分析和化学方法，以实现拟议的目标：目标1.将完成一个由4个铅系列组成的~350个化合物的文库，并使用FRET分析筛选SRC3共激活因子与Era和ER？的结合。ER与共激活子的相互作用被认为是表型的最小预测因子。ER的放射性配基置换是一种次级的、确证的检测方法。将获得ERA中具有激动剂/无效反应的部分激动剂，并使用来自Aim 2的数据进行迭代优化，为计算机辅助设计提供SAR开发。目的2.从FRET筛选中筛选出的ERA激动剂将在内源性ERA(MCF-7；T47D)和ER？(？43)乳腺上皮细胞和子宫内膜细胞中进行报告分析，以揭示其药效以及激动剂/拮抗剂的药理作用。部分激动剂将通过对ERE、AP-1和Sp1敏感基因的PCR测量来进一步研究。主要的表型分析是耐药的MCF7-5C细胞的凋亡。反筛选为亲本MCF7-5C和T47D细胞系的增殖。目的3.肝微粒体内的药物代谢、复合CYP抑制和口服血浆生物利用度将被用来提纯Era部分激动剂作为化学探针。我们在SERM代谢和在所有初步数据中使用口服分娩方面的丰富经验使我们对这种方法充满信心。DMPK研究将为动物研究提供最终选择。将使用三种不同的抗性异种移植模型来测试化学探针，并确定肿瘤消退的治疗指数。安全性将通过子宫生长和雌激素依赖的T47D异种移植生长的平行研究来预测。支持作用机制的研究仅限于ERA定位和靶点选择性蛋白质组学。这些目标的完成将为研究新的ER功能的部分激动剂和变构调节剂的潜力提供化学探针，并为未来在患者来源的PKCA高表达肿瘤的异种移植中测试先导化合物作为药物开发的前奏。