Full Project 3: Novel Bifunctional Anti-Andrgoens for Prostate Cancer

在前列腺癌的进展过程中，恶性细胞发生分子变化，其中AR 与伴侣蛋白相互作用以产生基因组以及非基因组信号传导， 在雄激素消除产生的低循环血清T存在下继续生长。这些细胞 不能通过标准的雄激素消除（即，LHRH+/-casodex）和它们的持续生长， 杀死病人。这种致命性在美国非洲裔美国男性中最高。到 解决这种健康差异，为这种雄激素消融抵抗患者开发有效的治疗方法是 这是本申请的焦点。我们的工作假设是，为什么目前的androoen消融治疗是 由于AR蛋白的构象在未被占据或被低分子量的 重量部分激动剂或拮抗剂，如Casodex。可以通过结合共活化剂而“被迫”置换 辅阻遏物，并经历诱导生长刺激信号传导的完全激动剂构象的变化。 因此，在雄激素消融失败的患者中阻断这种AR生长信号传导的新策略是： 开发“大体积双功能抗雄激素，其结合AR的配体结合结构域并在结构上锁定 AR表面的AF-2结构域处于拮抗剂构象，不允许其AF-2结构域被“强迫” 进入激动剂状态因此，具体目标1是设计合成一系列苄基或烷基11 β， 7 α侧链-δ 9 -19-去甲睾酮类似物，并测定它们与配体结合的亲和力 结构域（LED）的人AR及其体外抗雄激素能力对一系列人前列腺癌 细胞系具体目标2。四类类似物中的每一类的最好的类似物将通过它们的侧链偶联 与FK-506结合蛋白的合成配体（即，表示为SLF）以产生双功能结合类似物 其在与AR的LBD连接时也与FK-506结合，产生空间体积足够大的加合物， 防止任何AR辅激活因子结合。具体目标3。将测试SLF双功能类似物的 在雄激素消除的前列腺癌患者中，体外和体内对一系列人前列腺癌的有效性与casodex相比 环境为了及时实现这些目标，需要一种团队方法， 这是霍华德大学的Oladapo Bakare博士和约翰霍普金斯大学的John Isaacs博士合作完成的。 博士Bakare的专长是有机化学合成，他的实验室将合成所有建议的 类似物艾萨克斯博士的专长是肿瘤生物学和化学疗法，特别是前列腺 癌症，他的实验室将执行所有的生化，并在体外/体内评估的新的 合成化合物。

During the progression of prostatic cancer, malignant cells undergo molecular changes in which AR interacts with partner proteins to generate genomic as well as non-genomic signaling which allows their continuing growth in the presence of low circulating serum T produced by androgen ablation. Thus, these cells are not eliminated by standard androgen ablation (i.e.,LHRH+/-casodex) and their continuous growth eventually kills the patient. Such lethality is highest among our African-American males within the United States. To address this health disparity, developing effective therapy for such androgen ablation resistant patients is the focus of the present application. Our working hypothesis is that why present androoen ablation therapy is of limited efficacy because the conformation of the AR protein when either unoccupied or bound bv low molecular weight partial agonist or antagonist, like Casodex. can be "forced" by the binding of co-activators to displace co-repressors and undergo a change to a full agonist conformation inducing growth stimulation signaling. Therefore, a novel strategy to block such AR growth signaling in androgen ablation failing patients is to develop "bulky bifunctional anti-androgens which bind to the ligand binding domain of AR and structurally lock the AF-2 domain of the AR surface in an antagonist conformation not allowing its AF-2 domain to be "forced" into the agonist state. Therefore Specific Aim 1 is to design and synthesize a series of benzyl or alkyl 11beta and 7alpha side chain-delta9-19-nortestosterone analogs and determine their affinity for binding to the ligand binding domain (LED) of human AR and their in vitro anti-androgen ability against a series of human prostate cancer cell lines. In Specific Aim 2. the best of each of the four classes of analogs will be coupled via their side chain to a synthetic ligand for FK-506 binding protein (i.e., denoted SLF) to produce bifunctional binding analogs which while tethered to the LBD of AR also binds FK-506 producing an adduct sterically bulky enough to prevent any AR co-activator binding. In Specific Aim 3. the SLF bifunctional analogs will be tested for their efficacy vs. casodex in vitro and in vivo against a series of human prostate cancers in an androgen ablated environment. To achieve these goals in a timely fashion, a team approach is reguired involving the collaboration of Dr. Oladapo Bakare of Howard University and Dr. John Isaacs of Johns Hopkins University. Dr. Bakare's expertise is in organic chemical synthesis and his laboratory will synthesize all of the proposed analogs. Dr. Isaacs' expertise is in tumor biology and chemical therapeutics focused particularly on prostate cancer, and his laboratory will perform all of the biochemical, and in vitro/in vivo evaluations of the newly synthesized compounds.