Disruption of AKT Pathway for Cancer Intervention

破坏 AKT 通路以干预癌症

• 批准号: 6766348
• 负责人: Jin Q Cheng
• 金额: $ 31.96万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6766348
• 关键词: RNA interference; antineoplastics; apoptosis; athymic mouse; biological signal transduction; biomimetics; breast neoplasms; cell growth regulation; disease /disorder model; drug design /synthesis /production; drug screening /evaluation; enzyme activity; enzyme inhibitors; enzyme substrate; high throughput technology; isozymes; neoplasm /cancer chemotherapy; neoplasm /cancer pharmacology; neoplastic cell; neoplastic transformation; ovary neoplasms; prostate neoplasms; serine threonine protein kinase; tissue /cell culture

DESCRIPTION (provided by applicant): AKT is a major pathway to induce cell survival, growth and transformation. Three isoforms, AKT1, AKT2 and AKT3, have been identified from the AKT family. Frequent alterations of AKT, especially AKT2, have been detected in human malignancies. Ectopic expression of AKT induces chemo-resistance, whereas, dominant negative AKT sensitizes cells to chemotherapeutic drug-induced apoptosis. By screening the NCI diversity set that was derived from 140,000 compounds, we have recently obtained more than 30 compounds that significantly inhibited growth in AKT2-transformed, but not in pcDNA3-transfected NIH 3T3 cells. Further analyses show that two of them directly inhibited constitutively active AKT2 kinase activity, and another two directly decreased AKT phosphorylation. All four (4) compounds significantly inhibit growth in three (3) human cancer cell lines where the AKT pathway is altered. Based on these findings, we hypothesize that AKT is a critical therapeutic target for cancer intervention and that specific inhibitor(s) of AKT signaling will reduce tumorigenicity in tumors with elevated AKT activity. Since inhibition of AKT induces apoptosis in a range of mammalian cells, AKT inhibitor(s) could be effective, in combination with other anticancer drugs, for the treatment of tumors with other gene alterations. As accumulated studies show clearly biological/physiological function differences between three (3) isoforms of AKT, identification of inhibitor(s) for each isoform of AKT will enhance therapeutic efficacy and reduce side effects. The rationale for the proposed research is that AKT is frequently altered in human malignancy and that inhibition of AKT induces apoptosis and cell growth arrest. Therefore, development of specific AKT inhibitor(s) has great potential to improve cancer treatment and provide additional means to characterize the AKT signal transduction pathway. The objective of this project is to develop specific AKT inhibitors and evaluate their abilities to reverse malignant transformation of human tumors by disruption of the AKT pathway without gross toxicity. The specific aims are: (1) Validate AKT1, AKT2, and AKT3 as therapeutic targets in human cancer and identify lead compounds as potential disruptors of AKT by high-throughput screening of compounds from synthetic AKT substrate mimics and the NCI diversity set. (2) Determine the specificity of lead compounds in the inhibition of AKT pathway. (3) Examine the abilities of promising AKT inhibitor(s) to disrupt AKT signaling in intact cells and inhibit cell transformation by wild type and constitutively active AKT 1, AKT2 and AKT3. (4) Evaluate anti-tumor efficacy of active compounds in cell culture and animal models of human cancers where the PI3K/PTEN/AKT pathway is altered.

描述（由申请人提供）：AKT是诱导细胞存活、生长和转化的主要途径。 AKT 家族中已鉴定出三种同工型：AKT1、AKT2 和 AKT3。在人类恶性肿瘤中已检测到 AKT（尤其是 AKT2）的频繁改变。 AKT 的异位表达会诱导化疗耐药，而显性失活的 AKT 会使细胞对化疗药物诱导的细胞凋亡敏感。通过筛选源自 140,000 种化合物的 NCI 多样性集，我们最近获得了 30 多种化合物，这些化合物显着抑制 AKT2 转化的生长，但不抑制 pcDNA3 转染的 NIH 3T3 细胞的生长。进一步分析表明，其中两个直接抑制持续活跃的 AKT2 激酶活性，另外两个直接降低 AKT 磷酸化。所有四 (4) 种化合物均显着抑制 AKT 通路发生改变的三 (3) 种人类癌细胞系的生长。基于这些发现，我们假设 AKT 是癌症干预的关键治疗靶点，并且 AKT 信号传导的特定抑制剂将降低 AKT 活性升高的肿瘤的致瘤性。由于抑制 AKT 会诱导一系列哺乳动物细胞凋亡，因此 AKT 抑制剂与其他抗癌药物联合使用，可有效治疗具有其他基因改变的肿瘤。由于累积的研究清楚地表明三 (3) 种 AKT 亚型之间的生物学/生理功能差异，鉴定每种 AKT 亚型的抑制剂将增强治疗效果并减少副作用。这项研究的基本原理是 AKT 在人类恶性肿瘤中经常发生改变，并且抑制 AKT 会诱导细胞凋亡和细胞生长停滞。因此，开发特异性 AKT 抑制剂具有改善癌症治疗并提供表征 AKT 信号转导途径的额外方法的巨大潜力。该项目的目标是开发特定的 AKT 抑制剂，并评估其通过破坏 AKT 途径逆转人类肿瘤恶性转化的能力，且无明显毒性。具体目标是：(1) 验证 AKT1、AKT2 和 AKT3 作为人类癌症的治疗靶点，并通过对合成 AKT 底物模拟物和 NCI 多样性集的化合物进行高通量筛选，确定先导化合物作为 AKT 的潜在干扰物。 (2)确定先导化合物抑制AKT通路的特异性。 (3) 检查有前景的 AKT 抑制剂破坏完整细胞中 AKT 信号传导并抑制野生型和组成型活性 AKT 1、AKT2 和 AKT3 细胞转化的能力。 (4) 在 PI3K/PTEN/AKT 通路发生改变的人类癌症细胞培养物和动物模型中评估活性化合物的抗肿瘤功效。