RECEPTOR MEMBRANE ANCHORING WITH SYNTHETIC ANTIESTROGENS

用合成抗雌激素锚定受体膜

• 批准号: 6489325
• 负责人: BLAKE PETERSON
• 金额: $ 16.94万
• 依托单位: PENNSYLVANIA STATE UNIVERSITY, THE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6489325
• 关键词: chemical structure function; chemical synthesis; estradiol; estrogen inhibitor; estrogen receptors; genetic transcription; green fluorescent proteins; guanine nucleotide binding protein; ligands; receptor binding; reporter genes; surface plasmon resonance

Estrogen Receptors (hERs) are ligand-inducible transcription factors critical for the progression of breast cancers. The estrogen antagonist tamoxifen is used to treat breast carcinomas by blocking hormone binding to hERs. Although tamoxifen chemotherapy is beneficial, this drug causes endometrial (uterine) cancer. This serious side effect results from the inability of tamoxifen to fully inhibit hER function in the cell nucleus. The long-term objective of this research focuses on the development of a novel paradigm for total blockage of hER function. This paradigm is based on utilizing synthetic ligands to prohibit hER nuclear localization. The proposed research will test the following hypothesis: Since hERs affect transcription in the cell nucleus, novel synthetic ligands that recruit hERs to the plasma membrane will fully inhibit hER-mediated transcriptional activation. This hypothesis will be tested through evaluation and chemical synthesis of chimeric ligands with distinct hER-binding and membrane-binding domains. Surface plasmon resonance measurements of membrane anchoring functionality, chimeric hER ligands and hER-ligand complexes will be utilized to investigate membrane affinities in vitro. Furthermore, chimeric ligands will be analyzed in vivo through transcriptional reporter gene assays and green fluorescent protein assays of subcellular localization. Preliminary work has already demonstrated that (a) 7-alpha-substituted beta-estradiol hER ligands can be efficiently synthesized and (b) that hER-promoted reporter gene expression in vivo is abolished by genetically fusing the Ras membrane targeting sequence to hERs. Thus, Ras membrane targeting provides a much stronger directing force than hER nuclear localization signals. These data suggest that synthetic ligands that target hERs to the plasma membrane may confer total hormonal blockage, thereby providing more effective antiestrogen therapeutics. The strategy proposed herein has the potential to provide a novel approach to nuclear hormone receptor antagonism.

雌激素受体（HERS）是配体诱导的转录因子，对乳腺癌的进展至关重要。 雌激素拮抗剂他莫昔芬用于通过阻断激素与雌激素结合来治疗乳腺癌。 尽管他莫昔芬化疗是有益的，但该药物会导致子宫内膜（子宫）癌。 这种严重的副作用是由于他莫昔芬无法完全抑制其在细胞核中的功能而产生的。这项研究的长期目标集中在开发一种新型范式上，以完全阻塞其功能。 该范式基于利用合成配体来禁止其核定位。 拟议的研究将检验以下假设：由于HER会影响细胞核中的转录，因此将其募集到质膜的新型合成配体将完全抑制HER介导的转录激活。 该假设将通过评估和化学合成具有不同的HER结合和膜结合结构域的嵌合配体进行检验。 表面等离子体的膜锚定功能，嵌合体的配体和配体配合物的膜固定测量将用于体外研究膜亲和力。此外，将通过转录报告基因测定和亚细胞定位的绿色荧光蛋白测定法对嵌合体进行分析。初步工作已经证明，（a）可以有效合成她的配体的7-α-囊育的β-雌二醇，并且（b）在体内促进的记者基因表达被遗传融合，从而消除了ras膜靶向序列。 因此，RAS膜的靶向提供了比其核定位信号更强的指导力。 这些数据表明，将其靶向质膜的合成配体可能赋予总激素阻塞，从而提供更有效的抗雌激素疗法。 本文提出的策略有可能提供一种新的核激素受体拮抗方法。