Prevention of Lung Cancer Growth by Angiotensin-(1-7)

通过血管紧张素-(1-7)预防肺癌生长

• 批准号: 6686172
• 负责人: Ann Ann Tallant
• 金额: $ 7.2万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6686172
• 关键词: angiotensin receptor; angiotensins; apoptosis; cell cycle; cell line; cell proliferation; cell transformation; chemoprevention; flow cytometry; growth inhibitors; laboratory mouse; lung neoplasms; mitogen activated protein kinase; neoplastic growth; nucleic acid purification; polymerase chain reaction; receptor coupling; western blottings

DESCRIPTION (provided by applicant): Lung cancer is a leading cause of death in both men and women, accounting for approximately 160,000 deaths annually in the United States with over 1,000,000 new cases of lung cancer worldwide. Despite a number of clinical trials testing various compounds as chemopreventive agents, none were effective in reducing the risk of lung cancer. However, treatment of hypertensive patients with angiotensin converting enzyme (ACE) inhibitors reduced the risk of cancer, especially lung cancer. Inhibition of ACE activity decreases angiotensin II (Ang II) and increases the levels of both bradykinin and angiotensin-(1-7) [Ang-(1-7)]. We showed that Ang-(1-7) reduces vascular growth in vitro and prevents neointimal formation in vivo. More importantly, our preliminary studies showed that Ang-(1-7) markedly inhibits the growth of human lung cancer cells and reduces tumor growth in vivo. Thus, we propose that the antiproliferative response to Ang-(1-7) extends beyond its effects on vascular cells and that Ang-(1-7) inhibits the growth of cancer cells. The studies outlined in this application are designed to determine whether Ang-(1-7) inhibits the proliferation of human lung cancer cells and identify the molecular mechanisms involved in this regulation. Established cell lines of human lung carcinomas will be examined for growth inhibition following treatment with various doses of Ang-(1-7). Attenuation of cell growth will be assessed by 3H-thymidine incorporation into proliferating cells, reductions in cell number using the modified MTT assay, and cell cycle analysis by flow cytometry. The specificity of the antiproliferative response to Ang-(1-7) will be determined using other angiotensin peptides and receptor antagonists. The attenuation of lung cancer cell growth by Ang-(1-7) will be examined in mice with chemically-induced lung tumors, to demonstrate that Ang-(1-7) prevents or reduces lung tumor formation in vivo. Gene array analysis identified candidate genes regulated by Ang-(1-7) following mitogen stimulation of human lung cancer cells, including up-regulation of genes encoding tumor suppressors and cell death signals and downregulation of genes encoding signaling pathways stimulating cell growth. Regulation of specific genes and proteins by Ang-(1-7) will be assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) assays and Western blot hybridization, to determine their role in Ang-(1-7)-mediated lung cancer cell growth inhibition. The results of these studies will determine whether Ang-(1-7) effectively attenuates the proliferation of human lung cancer cells and identify the cellular pathways involved in the inhibitory response. The ultimate goal of this work is to determine whether administration of Ang-(1-7) or agents, which increase circulating Ang-(1-7) is an effective chemopreventive treatment for lung cancers.

描述(由申请人提供)： 肺癌是导致男性和女性死亡的主要原因，美国每年约有16万人死于肺癌，全球新增肺癌病例超过100万例。尽管一些临床试验测试了各种化合物作为化学预防药物，但没有一项在降低肺癌风险方面有效。然而，使用血管紧张素转换酶(ACE)抑制剂治疗高血压患者降低了患癌症的风险，尤其是肺癌。抑制血管紧张素转换酶活性可降低血管紧张素II(Ang II)，升高缓激肽和血管紧张素-(1-7)[Ang-(1-7)]水平。我们发现Ang-(1-7)在体外减少血管生长，并在体内阻止新生内膜的形成。更重要的是，我们的初步研究表明，Ang-(1-7)显著抑制人肺癌细胞的生长，并减少体内肿瘤的生长。因此，我们认为Ang-(1-7)的抗增殖反应超出了它对血管细胞的影响，并且Ang-(1-7)抑制了癌细胞的生长。本申请中概述的研究旨在确定Ang-(1-7)是否抑制人肺癌细胞的增殖，并确定参与这一调控的分子机制。已建立的人肺癌细胞系将在不同剂量的Ang-(1-7)处理后进行生长抑制检测。通过~3H-胸腺嘧啶核苷掺入增殖细胞、用改良的四甲基偶氮唑盐比色法测定细胞数量、用流式细胞仪分析细胞周期来评估细胞生长抑制。Ang-(1-7)的抗增殖反应的特异性将用其他血管紧张素肽和受体拮抗剂来确定。Ang-(1-7)对肺癌细胞生长的抑制作用将在化学诱发肺癌的小鼠身上进行检测，以证明Ang-(1-7)可以预防或减少体内肺癌的形成。基因芯片分析确定了Ang-(1-7)在人肺癌细胞有丝分裂原刺激后调节的候选基因，包括编码肿瘤抑制因子和细胞死亡信号的基因上调，以及编码刺激细胞生长的信号通路的基因下调。通过逆转录聚合酶链式反应(RT-PCR)和Western印迹杂交检测Ang-(1-7)对特定基因和蛋白的调节作用，以确定它们在Ang-(1-7)介导的肺癌细胞生长抑制中的作用。这些研究的结果将确定Ang-(1-7)是否有效地抑制人肺癌细胞的增殖，并确定参与抑制反应的细胞途径。这项工作的最终目标是确定给予Ang-(1-7)或增加循环Ang-(1-7)的药物是否是肺癌的有效化学预防治疗。