Evaluation of a novel AKT inhibitor in ovarian cancer

描述（由申请人提供）：本研究项目将侧重于评估一种新的AKT选择性小分子抑制剂在卵巢癌细胞中的作用以及该抑制剂对AKT下游靶点的影响。AKT或蛋白激酶B （PKB）是一种丝氨酸/苏氨酸激酶，在生长因子或细胞因子的作用下被激活。AKT蛋白有三个亚型AKT1 （PKBalpha）、AKT2 （PKBbeta）和AKT3 (PKBgamma)，它们具有大于85%的序列同一性和相同的结构组织。AKT2原癌基因在卵巢癌中扩增。在卵巢癌细胞和肿瘤中也经常检测到AKT1磷酸化和AKT1激酶活性升高。AKT改变的卵巢癌患者预后较差。由于AKT可能提供一种生存信号，保护细胞免受抗癌药物或应激诱导的凋亡，因此开发针对AKT的强效和选择性抑制剂是治疗卵巢癌的一种有吸引力的治疗策略。通过基于结构的设计和筛选，我们已经确定了一种有效的选择性AKT小分子抑制剂（称为API-59）。在本研究中，我们拟评估API-59在AKT活性升高的卵巢癌细胞中的效价、选择性和分子机制。为解决这一概念，将研究以下具体目标：

DESCRIPTION (provided by applicant): This research project will focus on the evaluation of a novel AKT-selective small molecule inhibitor in ovarian cancer cells and the effect of this inhibitor on AKT downstream targets. AKT or Protein Kinase B (PKB) is a serine/threonine kinase that is activated in response to growth factor or cytokine. The AKT protein has three isoforms AKT1 (PKBalpha), AKT2 (PKBbeta) and AKT3 (PKBgamma) that have greater than 85% sequence identity and have the same structural organization. The AKT2 proto-oncogene is amplified in ovarian carcinoma. The elevated AKT1 phosphorylation and AKT1 kinase activity have also been detected frequently in ovarian cancer cells and tumors. Ovarian cancer patients with AKT alterations appear to have a poor prognosis. Since AKT may provide a survival signal that protects cells from apoptosis induced by anti-cancer drugs or stresses, development of potent and selective inhibitors targeting AKT is an attractive therapeutic strategy for treating ovarian carcinoma. Through structure-based design and screening, we have identified a potent and selective small molecule inhibitor of AKT (termed API-59). In this proposal, we propose to evaluate the potency, selectivity and molecular mechanism of API-59 in ovarian cancer cells that express elevated AKT activity. The following specific aims will be studied to address this concept: 1. Evaluation of the effect of API-59 on AKT pathway in ovarian cancer cells. 1.1. Synthesis of API-59. 1.2. Evaluate induction of apoptosis by API-59 in ovarian cancer cell lines that express constitutively active AKT. 1.3. Determine the effect of API-59 on AKT kinase activity and AKT downstream targets. 1.4. Evaluate the effect of API-59 on normal cells lacking constitutively active AKT. 2. Examination of the effect of API-59 in combination with cytotoxic agents in ovarian cancer cells. 2.1. Test the effect of API-59 in combination with cisplatin on inducing apoptosis and inhibiting the AKT pathway in ovarian cancer cell lines that express constitutively active AKT. 2.2. Examine the inhibitory effect of API-59 in combination with taxol on inducing apoptosis and inhibiting the AKT pathway in ovarian cancer cells that express constitutively active AKT. 3. Evaluation of the efficacy of API-59 in a nude mouse tumor model in vivo. Determine the efficacy of API-59 treatment to inhibit elevated AKT activity in established mice tumors and retard the growth of established tumors in nude mice.