Vitamin D and Progestins for the Chemoprevention of Fallopian Tube/Ovarian Cancer

项目总结/摘要 通过预防降低卵巢癌的发病率有很大的潜力。口服避孕药 (OCs)使患上皮性卵巢癌的风险降低30 - 50%，这表明有效的 使用激素的预防方法是可能的。孕激素有效的OC赋予两倍的卵巢癌 作为新的弱势业主立案法团的保护。这些数据表明，以孕激素为基础的药理学策略 可能对预防卵巢癌非常有效。孕激素的效力可以通过 与维生素D的组合，维生素D是第二种预防剂，当作为 胆钙化醇;因此，这两种药物可以协同作用于化学预防终点， 因此，孕激素对维生素D代谢有积极影响。卵巢起源组织 癌症仍然不确定。现在有令人信服的证据表明，许多高级别卵巢癌的起源 癌细胞可能是输卵管，因此为确定输卵管中的分子靶点创造了机会。 卵巢癌的早期症状有哪些？这项研究旨在确定 卵巢癌，无论是起源于卵巢还是输卵管， 防止。预防输卵管/卵巢癌使用维生素D和三种维生素的组合 将在以下三个目标中测试各类孕激素。首先，这些治疗对 将研究导致输卵管和卵巢上皮细胞中细胞死亡的分子途径。 这将包括通过抑制CYP24A1延长维生素D的活性寿命，以及增加 通过增强维生素D受体的产生来增强这些细胞对维生素D的敏感性。二是 孕酮受体和孕酮反应元件PRE之间的相互作用将是 通过使用CYP24A1启动子-荧光素酶报告基因在CYP24A1启动子中机制性定义 结构。卵巢癌细胞系中的内源性功能性PRE将被选择性灭活， CRISPR/Cas9介导的基因组编辑。将所得到的含有非功能性PRE的稳定细胞系在细胞中表达。 CYP24A1启动子随后将用于验证孕酮和维生素D之间协同作用的丧失， 在小鼠异种移植物中的体外以及体内。第三，使用两种转基因小鼠进行体内实验， 将对发生与人类卵巢癌非常相似的输卵管癌的菌株进行试验， 确定孕激素和维生素D对输卵管上皮癌发展的体内影响。 了解孕激素参与这些过程的机制， 促进开发一种预防卵巢/输卵管癌的稳健药理学方法。目标 这项研究的目的是确定一种最佳的药理学策略，结合孕激素和维生素D， 一种有效的卵巢癌化学预防方法，可以在有卵巢癌风险的女性中进行测试。 癌

Project Summary/Abstract There is significant potential to decrease ovarian cancer incidence through prevention. Oral contraceptives (OCs) confer a 30-50% reduced risk of developing epithelial ovarian cancer, suggesting that an effective preventive approach using hormones is possible. Progestin-potent OCs confer twice the ovarian cancer protection as newer weak-progestin OCs. These data suggest that a progestin-based pharmacologic strategy may be highly effective for prevention of ovarian cancer. Progestin potency can be enhanced through combination with vitamin D, a second preventive agent that is also non-toxic when administered as cholecalciferol; therefore, the two agents may act synergistically on chemopreventive endpoints in the gynecologic tract such that progestins positively influence vitamin D metabolism. The tissue of origin of ovarian cancer remains uncertain. There is now compelling evidence that the origin of many high grade ovarian cancers may be the fallopian tube, thus creating an opportunity for identifying molecular targets in the fallopian tube for effective ovarian cancer prevention. The proposed research is designed to determine the molecular mechanisms by which ovarian cancer, whether it originates from the ovary or the fallopian tube, may be prevented. Prevention of fallopian tube/ovarian cancer using a combination of vitamin D and each of the three classes of progestins will be tested in the following three aims. First, the impact of these treatments on molecular pathways that lead to cell death in fallopian tube and ovarian epithelial cells will be investigated. This will include extension of the active life of vitamin D by inhibition of CYP24A1, as well as increased sensitivity of these cells to vitamin D by enhanced production of the vitamin D receptor. Secondly, the interaction between the progesterone receptor and progesterone response elements PRE(s) will be mechanistically defined in the CYP24A1 promoter through the use of CYP24A1 promoter-luciferase reporter constructs. Endogenous functional PRE(s) in ovarian cancer cell lines will be selectively inactivated using CRISPR/Cas9-mediated genome editing. The resulting stable cell line(s) harboring non-functional PRE(s) in the CYP24A1 promoter will then be used to validate loss of synergy between progesterone and vitamin D in vitro as well as in vivo in mouse xenografts. Thirdly, in vivo experiments using two genetically modified mouse strains that develop fallopian tube cancer closely resembling human ovarian cancer will be performed to determine the in vivo impact of progestins and vitamin D on fallopian tube epithelial cancer development. Understanding the mechanisms by which progestins are integrally involved in each of these processes, will facilitate development of a robust pharmacologic approach to prevent ovarian/fallopian tube cancer. The goal of this research is to identify an optimal pharmacologic strategy combining progestins and vitamin D for an effective ovarian cancer chemopreventive approach that can be tested in women at risk of developing ovarian cancer.