Progression and regression of mammary preneoplasia

描述（申请人提供）：长期目标是改善乳腺癌预防战略。该项目利用遗传工程小鼠模型，代表临床相关的雌激素信号分子畸变与人类乳腺组织的高风险妇女，以解决三个需求。第一，正在发现候选体内生物标志物和内在抗性途径。第二，开发一个基于人体组织的系统，以平行于我们基于小鼠的实验模型。三、他莫昔芬替代药物的疗效及作用机制比较。基因工程小鼠模拟了高危女性中某些类型乳腺癌的病理生理学。来自高危女性的原代组织代表了“真实的东西”，但随着组织和细胞被转移到体外环境中进行实验，它们也成为模型系统。固定组织和特定时间点的基因表达研究提供了高风险乳腺环境的静态但信息丰富的表示。需要新的体外系统来改善对不同遗传环境中的治疗剂的预测益处的预测，以“个性化”医疗干预。2001年。比较替代预防药物雷洛昔芬，来曲唑和efatutazone的影响，他莫昔芬在遗传环境中表现出或可能表现出内在他莫昔芬耐药。目标2.创建一个人类原发性非恶性但“高乳腺癌风险”乳腺上皮细胞的活体生物库。使用这个活体生物库研究体外方法来测试他莫昔芬（和未来的其他候选预防药物）的敏感性。目标3.探索替代给药方案，以提高替代预防剂efatutazone（一种PPARγ激动剂，具有预防ER+和ER-乳腺癌的潜力）的有效性和/或降低毒性。研究方法：还采用了5种基因工程小鼠模型（乳腺上皮细胞中Esr 1（雌激素受体α）或CYP 19 A1（芳香酶）表达条件性增加和乳腺上皮细胞靶向全长Brca 1缺失伴生殖系Trp 53单倍型不足的组合） 在采用大规模筛选技术（RNAseq和反相蛋白微阵列）的实验中，作为原代人乳腺上皮细胞，在不同条件下（条件性重编程细胞、球状体和乳腺球培养物）进行原代细胞培养，给予不同的候选预防剂他莫昔芬、雷洛昔芬、来曲唑和依法他宗。相关性：他莫昔芬是目前FDA批准用于绝经前和绝经后妇女乳腺癌预防的唯一选择性雌激素受体调节剂（SERM），雷洛昔芬批准用于绝经后妇女。本研究将从分子水平上了解不同的遗传病变如何影响预防药物反应，探索体外系统的开发，以测试临床样本中的预防药物反应，并测试不同的治疗方案是否可以提高PPARγ激动剂efatutazone的治疗率。

DESCRIPTION (provided by applicant):.The long-term objective is to improve breast cancer prevention strategies. This project exploits genetically engineered mouse models representing clinically relevant molecular aberrations in estrogen signaling in parallel with human breast tissue from high-risk women to address three needs. One, on-going discovery of candidate in vivo biomarkers and pathways of intrinsic resistance. Two, development of a human tissue based system to parallel our mouse-based experimental models. Three, comparison of efficacy and mechanism of alternative agents to tamoxifen. Genetically engineered mice model the pathophysiology of some types of breast cancer found in high-risk women. Primary tissue from high-risk women represents the 'real thing' but as the tissue and cells are moved into in vitro environments to perform experiments they also become model systems. Fixed tissue and studies of gene expression at specific time points provide static but informative representations of the high-risk breast environment. New in vitro systems are needed to improve projections of predicted benefit to therapeutic agents in different genetic environments, to 'personalize' medical intervention. Objective1. Compare impact of alternative preventive agents raloxifene, letrozole and efatutazone to tamoxifen in genetic settings exhibiting or likely to exhibit intrinsi tamoxifen resistance. Objective 2. Create a living biobank of human primary non-malignant but 'high breast cancer risk' mammary epithelial cells. Investigate in vitro approaches for testing tamoxifen (and other candidate preventive agents in the future) sensitivity using this living biobank. Objective 3. Explore alternative schedules of administration to increase effectiveness and/or reduce toxicity for an alternative preventive agent efatutazone, a PPARγ agonist, which has potential to prevent both ER+ and ER- breast cancer. Methods: Employ five genetically engineered mouse models (combinations of conditional increased Esr1 (Estrogen Receptor alpha) or CYP19A1 (Aromatase) expression in mammary epithelial cells and mammary epithelial cell-targeted loss of full-length Brca1 with germline Trp53 haploinsufficiency) as well as primary human mammary epithelial cells in experiments that employ large-scale screening technologies (RNAseq and reverse phase protein microarrays), primary cell culture under different conditions (conditional reprogrammed cells, spheroid and mammosphere culture), with administration of different candidate preventive agents tamoxifen, raloxifene, letrozole and efatutazone. Relevance: Tamoxifen is the only Selective Estrogen Receptor Modulator (SERM) currently FDA- approved for breast cancer prevention in pre- and post-menopausal women with raloxifene approved for post- menopausal women. This study will provide a molecular understanding of how different genetic lesions influence preventive agent response, explore development of in vitro systems that could test preventive agent response in clinical samples, and test if different treatment schedules can improve the therapeutic ratio of the PPARγ agonist efatutazone.