Progression and regression of mammary preneoplasia

简介(申请人提供)：长远目标是改善乳癌预防策略。该项目利用基因工程小鼠模型，在雌激素信号中表现出临床相关的分子异常，同时利用来自高危女性的人类乳房组织来满足三个需求。一是正在发现体内候选生物标记物和内在耐药途径。第二，开发一个基于人体组织的系统，以平行于我们基于老鼠的实验模型。三、三苯氧胺替代药的疗效及作用机制比较。基因工程小鼠对高危女性中发现的某些类型乳腺癌的病理生理学进行建模。来自高危女性的原始组织代表了“真实的东西”，但随着这些组织和细胞被转移到体外环境中进行实验，它们也成为了模型系统。固定的组织和对特定时间点的基因表达的研究提供了对高危乳房环境的静态但信息表示。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期益处的预测，以‘个性化’医疗干预。目标1.比较替代预防药物雷洛昔芬、来曲唑和依法他酮对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的影响。目的2.建立人类原代非恶性、高乳腺癌风险乳腺上皮细胞的活生物库。使用这个活的生物库研究测试他莫昔芬(和未来的其他候选预防药物)敏感性的体外方法。目的3.探索替代预防性给药方案，以提高疗效和/或降低毒性。伊法妥他酮是一种PPARγ激动剂，具有预防ER+和ER-乳腺癌的潜力。方法：采用5种基因工程小鼠模型(乳腺上皮细胞ESR1(雌激素受体α)或CYP19A1(芳香酶)条件表达增加和乳腺上皮细胞靶向缺失全长BRCA1伴Trp53单倍体功能不全)。 在采用大规模筛选技术(RNAseq和反相蛋白质微阵列)的实验中，将人乳腺上皮细胞作为原代细胞，在不同条件下进行原代细胞培养(条件重编程细胞、球体和乳房培养)，并给予不同候选预防性药物他莫昔芬、雷洛昔芬、来曲唑和依伐他酮。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)，雷洛昔芬被批准用于绝经后妇女。这项研究将提供不同的遗传损伤如何影响预防性药物反应的分子理解，探索能够在临床样本中测试预防性药物反应的体外系统的开发，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.