Developing Fisetin for the Managment of Prostate Cancer

摘要 前列腺癌是最常见的癌症，也是第二常见的致癌原因。 美国男性中的相关死亡。尽管预防和治疗方面的进步总体上有所改善 为了生存，显然仍然需要有效的、基于机制的办法，以实现长期的 在前列腺癌的管理方面有所改善。在众多信令网络中， 与前列腺癌的发生有关的是雷帕霉素的PTEN/AKT/哺乳动物靶点 (AKT/mTOR)和MAPK通路。值得注意的是，PTEN/AKT/mTOR和MAPK信号通路的功能 协同促进肿瘤生长和激素难治性疾病的出现。这些观察结果 我们的建议是同时靶向PTEN/Akt/mTOR和MAPK信号转导 通路可能是抑制前列腺上皮内瘤变(PIN)发展的有效策略 并将其转化为癌症。符合这一假设，并在我们对无毒饮食制剂的追求中 化学预防，我们最近用一种结构独特的非瑟素进行了一些新颖而令人兴奋的观察。 属于多酚的类黄酮族的化学物质。前列腺癌PC3细胞的治疗 Fesetin可抑制mTOR激酶信号转导。使用一种独特的人类前列腺上皮家族 我们观察到在前列腺癌发生过程中模拟多个步骤的细胞系转化为 成瘤潜能增加的细胞表现出更高的mTOR信号转导和对Fisetin的更高敏感性 诱导细胞死亡。更有趣的是，使用分子模型，我们观察到菲西汀在物理上相互作用 与mTOR分子结合，并在两个位置对接，结合能为-8Kcal/mol。这些观察结果 提供证据表明，非瑟素作为一种新的mTOR信号复合体抑制剂，导致诱导 细胞死亡。在此应用程序中，我们建议利用Fisetin针对多个信令的能力 利用一个独特的6人前列腺上皮细胞家族，在体外研究其通路和有效性 使用基因工程Nkx3.1/Pten突变小鼠模型的活体，该模型概括了许多特征 人类前列腺癌。与当前研究最相关的是，Nkx3.1/Pten突变小鼠显示出激活的 AKT/mTOR和MAPK信号在癌症进展中的作用。因此，我们推断这些Nkx3.1/Pten 小鼠应该提供一个很好的临床前模型来测试同时靶向的后果 AKT/mTOR和ERK MAPK信号与前列腺癌的发生在此应用程序中，我们将1)建立 PTEN/Akt/mTOR和MAPK信号转导通路的参与及Fisetin的作用 模拟前列腺过程中多个步骤的独特的人前列腺上皮细胞系家族 致癌，2)研究膳食中鱼腥草素的作用及其与PTEN/Akt/mTOR和MAPK的关系 PIN和雄激素依赖型腺癌发生发展中的信号转导途径 Nkx3.1/Pten小鼠前列腺癌模型的建立及3)非瑟丁抗去势作用的研究 Nkx3.1/Pten突变小鼠模型诱导雄激素非依赖性腺癌的研究 前列腺癌。这一提议的成功完成可能会导致菲赛汀作为一部小说的发展 预防和可能用于前列腺癌治疗的试剂。

ABSTRACT Prostate cancer is the most commonly diagnosed cancer and the second most common cause of cancer related deaths among men in the US. Although advances in prevention and treatment have improved overall survival, there remains a clear need for effective mechanism-based approaches that can achieve long-term improvements in the management prostate cancer. Among the many signaling networks that have been implicated in the development of prostate cancer are the PTEN/AKT/mammalian target of rapamycin (AKT/mTOR) and MAPK pathways. Notably, the PTEN/AKT/mTOR and MAPK signaling pathways function cooperatively to promote tumor growth and the emergence of hormone-refractory disease. These observations form the basis of our proposal that simultaneous targeting of the PTEN/Akt/mTOR and the MAPK signaling pathways may be an effective strategy for inhibiting the development of prostatic intraepithelial neoplasia (PIN) and its conversion to cancer. In line with this hypothesis and in our pursuit for non-toxic dietary agents for chemoprevention, we recently made some novel and exciting observations with fisetin, a structurally distinct chemical substance that belongs to the flavonoid group of polyphenols. Treatment of prostate cancer PC3 cells with fisetin resulted in inhibition of mTOR kinase signaling. Using a unique family of human prostate epithelial cell lines that mimic multiple steps in the process of prostate carcinogenesis we observed that transformed cells with increased potential for tumorigenesis exhibit higher mTOR signaling and greater sensitivity to fisetin induced cell death. More interestingly, using molecular modeling we observed that fisetin physically interacts with the mTOR molecule and docks at two sites with a binding energy of -8Kcal/mol. These observations provide evidence that fisetin functions as a novel inhibitor of mTOR signaling complex leading to induction of cell death. In this application we propose to take advantage of fisetin's ability to target multiple signaling pathways and investigate its efficacy in vitro using a unique family of six human prostate epithelial cells and in vivo using a genetically engineered Nkx3.1/Pten mutant mouse model that recapitulates many features of human prostate cancer. Most relevant for the current study, Nkx3.1/Pten mutant mice display activation of AKT/mTOR and MAPK signaling during cancer progression. Therefore, we reasoned that these Nkx3.1/Pten mice should provide an excellent preclinical model to test the consequences of simultaneous targeting of AKT/mTOR and ERK MAPK signaling for prostate tumorigenesis. In this application we will 1) establish the involvement of PTEN/Akt/mTOR and the MAPK signaling pathways and determine the efficacy of fisetin in a unique family of human prostate epithelial cell lines that mimic multiple steps in the process of prostate carcinogenesis, 2) investigate the effects of dietary fisetin and involvement of PTEN/Akt/mTOR and the MAPK signaling pathways during the development of PIN and androgen dependent adenocarcinoma in the Nkx3.1/Pten mouse model of prostate cancer and 3) investigate the efficacy of fisetin against castration induced androgen independent adenocarcinoma in the Nkx3.1/Pten mutant mouse model of advanced prostate cancer. A successful completion of this proposal may result in the development of fisetin as a novel agent for prevention and possibly for the treatment of prostate cancer.