Lung Cancer Chemoprevention using Deguelin

使用 Deguelin 进行肺癌化学预防

• 批准号: 6941229
• 负责人: HO-YOUNG LEE
• 金额: $ 24.76万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6941229
• 关键词: apoptosis; biotherapeutic agent; cancer prevention; cell transformation; chemoprevention; clinical research; enzyme activity; gene targeting; genetically modified animals; heat shock proteins; human tissue; immunocytochemistry; laboratory mouse; lung neoplasms; neoplasm /cancer pharmacology; neoplastic growth; nonsmall cell lung cancer; plant extracts; protooncogene; respiratory epithelium; transfection; western blottings

DESCRIPTION (provided by applicant): In the United States, lung cancer leads all other cancers in both incidence and mortality rate. Clearly, there is an urgent need to develop novel chemopreventive and therapeutic approaches for lung cancer. Toward this goal, we have investigated novel strategies targeting intracellular mechanisms that promote survival and suppress apoptosis of premalignant and malignant human bronchial epithelial (HBE) cells and lung cancer cells. One effective strategy is to use the deguelin, isolated from Mundulea sericea (Leguminosae), which targets Akt that plays a major role in cell survival, transformation, end apoptosis. This proposal is based on findings which have shown that: A) Akt is constitutively active in pramalignant and malignant HBE cells. B) Akt is also highly active in most NSCLC cell lines, probably owing to the activating mutations of ras, overexpression of the tyrosine kinase receptor EGFR family and one of its ligands, transforming growth factor alpha (TGF-alpha), elevated levels of the subunits of PI3K, and reduced level of PTEN expression. C) Activation of Akt is an early biochemical effect of tobacco components; increased expression of pAkt (Ser473) has been observed in reactive epithelium specimens (bronchial hyperplasia and squamous metaplasia), bronchial dysplasia, and NSCLC from current and formal smokers. D) Targeting the Akt pathway using pharmacological or genetic approaches efficiently inhibited Akt activity and suppressed the proliferation of premalignant and malignant HBE cells as well as NSCLC cells without detectable cytotoxicity on normal HBE cells. E) Deguelin strongly inhibited Akt activity, in association with suppression of the growth and induction of apoptosis in premalignant and malignant HBE cells as well as a subset of NSCLC cells, with minimum effects on normal HBE cells at in vitro dosages attainable in vivo. F) Deguelin also inhibited expression of COX-2, which is largely regulated by Akt, that participates in xenobiotic metabolism, angiogenesis, inhibition of immune surveillance, and suppression of apoptosis during tumorigenesis. G) Pharmacokinetic studies in rats and mouse showed that a nontoxic dose of deguelin (1 mu/M), delivered intravenously or by oral gavage, is achievable in a variety of tissues in vivo, including lung tissue. All of these findings provide a strong rationale to use deguelin as a chemopreventive and/or chemotherapeutic agent in lung cancer. We recently found that deguelin decreased the levels of a subset of client proteins of heat-shock protein 90, including PDK-1 and Akt, in NSCLC cells, suggesting that deguelin inactivated APt pmt|y by regulating the function of Hsp90. These and other studies have led to the following hypotheses: 1) Akt activation is sufficient for HBE cell transformation and is required for the survival of transformed HBE cells. 2) Inhibition of Akt activity prevents lung tumor development. 3) Deguelin inactivates Akt by decreasing stability of PDK-1 and Akt through blockade of Hsp90 in transformed HBE and NSCLC cells. In this RO1 application, I propose to test these hypotheses by exploring the following Specific Aims: 1) To determine whether constitutive activation of the Akt induces malignant transformation of HBE cells. 2) To determine whether inhibition of Akt activity by deguelin demonstrates lung cancer chemopreventive and/or therapeutic activity in mouse models of lung cancer. 3) To investigate the mechanism through which deguelin inactivates Akt in transformed HBE cells and NSCLC cells. We expect that evaluating the chemopreventive/chemotherapeutic activities of deguelin in animal model of lung cancer and understanding the mechanism by which deguelin regulates Akt activity may lead to the development of novel strategies for chemoprevention as well as treatment in lung cancer.

描述（由申请人提供）：在美国，肺癌在发病率和死亡率方面领先于所有其他癌症。显然，迫切需要开发新的肺癌化学预防和治疗方法。为了实现这一目标，我们研究了新的战略，针对细胞内机制，促进生存和抑制癌前和恶性人支气管上皮细胞（HBE）和肺癌细胞凋亡。一种有效的策略是使用从Mundulea sericea（Legumarium）中分离的鱼藤素，其靶向在细胞存活、转化、最终凋亡中起主要作用的Akt。这一建议是基于已经显示的发现：A）Akt在恶变前和恶性HBE细胞中是组成型活性的。B）Akt在大多数NSCLC细胞系中也是高度活性的，这可能是由于ras的活化突变、酪氨酸激酶受体EGFR家族及其配体之一、转化生长因子α（TGF-α）的过表达、PI 3 K亚基水平的升高以及PTEN表达水平的降低。C）Akt的激活是烟草成分的早期生化效应;在当前和正式吸烟者的反应性上皮标本（支气管增生和鳞状化生）、支气管发育不良和非小细胞肺癌中观察到pAkt（Ser 473）表达增加。D）使用药理学或遗传学方法靶向Akt途径有效地抑制Akt活性并抑制癌前和恶性HBE细胞以及NSCLC细胞的增殖，而对正常HBE细胞没有可检测的细胞毒性。E）鱼藤素强烈抑制Akt活性，与癌前和恶性HBE细胞以及NSCLC细胞亚群中生长的抑制和细胞凋亡的诱导相关，在体内可达到的体外剂量下对正常HBE细胞的影响最小。F）鱼藤素还抑制考克斯-2的表达，其在很大程度上受Akt调节，其参与肿瘤发生期间的异生物质代谢、血管生成、免疫监视的抑制和细胞凋亡的抑制。G）在大鼠和小鼠中的药代动力学研究表明，静脉内或通过口服管饲法递送的鱼藤素的无毒剂量（1 μ/M）在体内的多种组织（包括肺组织）中可实现。所有这些发现提供了一个强有力的理由使用鱼藤素作为化学预防和/或化疗剂在肺癌。我们最近发现鱼藤素降低了NSCLC细胞中热休克蛋白90的一部分客户蛋白的水平，包括PDK-1和Akt，这表明鱼藤素灭活了APt pmt| y通过调节Hsp 90的功能。这些和其他研究导致了以下假设：1）Akt活化足以用于HBE细胞转化，并且是转化的HBE细胞存活所需的。2)抑制Akt活性可防止肺肿瘤的发展。3)鱼藤素通过阻断转化的HBE和NSCLC细胞中的Hsp 90降低PDK-1和Akt的稳定性来灭活Akt。在本RO 1申请中，我提出通过探索以下具体目的来检验这些假设：1）确定Akt的组成性激活是否诱导HBE细胞的恶性转化。2)确定鱼藤素对Akt活性的抑制是否在肺癌小鼠模型中表现出肺癌化学预防和/或治疗活性。3)探讨鱼藤素对转化的HBE细胞和NSCLC细胞中Akt的失活机制。我们期望通过评估鱼藤素在肺癌动物模型中的化学预防/化学治疗活性，并了解鱼藤素调节Akt活性的机制，可能会导致肺癌化学预防和治疗的新策略的发展。