Preclinical evaluation of NOS inhibitors for the treatment of pancreatic cancer

描述（由申请人提供）：胰腺癌是一种毁灭性的疾病，在美国每年造成约33,370人死亡，5年生存率仅为5%。这种癌症的分子标志是小GTPase KRas的激活突变，众所周知，它可以促进肿瘤的发生。不幸的是，很难从药理学上抑制KRas，这促使我们确定KRas肿瘤发生所需的药物蛋白。我们发现，致癌KRas通过激活AKT，刺激内皮型一氧化氮合酶（eNOS）。此外，在人胰腺癌细胞系中敲低eNOS或在小鼠中基因消融eNOS基因可以延缓致癌的ras驱动肿瘤的生长。NOS酶的小分子量抑制剂已在感染性休克和心源性休克的I至III期临床试验中进行了测试。利用NOS抑制剂治疗其他疾病的发展，我们测试并发现NOS抑制剂L-NAME阻碍人类胰腺癌细胞系的肿瘤生长。我们建议现在测试两种最常用的NOS抑制剂，L- NAME和L- nmma的抗肿瘤活性。这两种药物都很容易给药，可以口服，并且已经在老鼠、大型哺乳动物和人类身上进行了研究。我们将使用两种建立良好的胰腺癌小鼠模型来测试这两种NOS抑制剂的抗肿瘤活性：人类胰腺癌异种移植物（目的1），因为这些细胞来源于人类癌症，这是一个重要的考虑因素，因为致癌Ras信号在人类和啮齿动物细胞之间可能不同；和胰腺表达致癌KRAS转基因小鼠（aim 2），这更好地反映了胰腺癌在正确器官的建立。总之，这两个非常不同的模型将使我们能够确定L- NAME和L- nmma在多大程度上以及在什么条件下阻碍胰腺肿瘤的发生。反过来，这些研究应该为潜在的临床试验奠定临床前基础。公共卫生相关性：胰腺癌是最致命的癌症之一，治疗选择很少。我们发现eNOS酶是胰腺肿瘤生长所必需的，并且可以用现有的小分子量抑制剂在药理学上加以抑制。因此，为测试NOS抑制剂的抗肿瘤活性而提出的研究与人类健康具有重要的相关性，特别是作为胰腺癌的新治疗方式。

DESCRIPTION (provided by applicant): Pancreatic cancer is a devastating disease, causing an estimated 33,370 deaths per year in the USA with a five-year survival rate of only 5%. The molecular hallmark of this cancer is an activating mutation in the small GTPase KRas, which is well known to promote tumorigenesis. Unfortunately, it has been difficult to pharmacologically inhibit KRas, prompting us to identify druggable proteins required for KRas oncogenesis. We found that oncogenic KRas, through activation of AKT, stimulates the enzyme endothelial Nitric Oxide Synthase (eNOS). Moreover, knockdown of eNOS in human pancreatic cancer cell lines or genetic ablation of the eNOS gene in mice retarded oncogenic Ras-driven tumor growth. Small molecular weight inhibitors of NOS enzymes have been tested in phase I to III clinical trials of septic and cardiogenic shock. Capitalizing on the development of NOS inhibitors for the treatment of other diseases, we tested and found that the NOS inhibitor L-NAME impeded tumor growth of human pancreatic cancer cell lines. We propose to now test the two most developed general NOS inhibitors, L- NAME and L-NMMA, for anti-tumor activity. Both these drugs are very easy to administer, being orally available, and have been studied in mice, large mammals and humans. We will use two well established mouse models of pancreatic cancer to test the anti-tumor activity of these two NOS inhibitors: human pancreatic cancer xenografts (aim 1) as such cells are derived from human cancers, an important consideration as oncogenic Ras signaling can differ between human and rodent cells; and pancreatic expressed-oncogenic KRAS transgenic mice (aim 2), which better reflect the establishment of pancreatic cancer in the correct organ. Together, these two very different models will allow us to determine how broadly and under what conditions L- NAME and L-NMMA impede pancreatic tumorigenesis. These studies should, in turn, lay the preclinical groundwork for a potential clinical trial. PUBLIC HEALTH RELEVANCE: Pancreatic cancer is one of the most deadliest cancers with very few therapeutic options. We discovered the enzyme eNOS is required for pancreatic tumor growth and can be pharmacologically inhibited with available small molecular weight inhibitors. The studies proposed to test NOS inhibitors for anti-tumor activity thus have important relevance to human health, specifically as possible new treatment modalities for pancreatic cancer.