Pemetrexed and sildenafil for lung cancer

描述（由申请方提供）：在本申请中，我们拟基于培美曲塞（NCT 01450384）的经验，开发一种联合标准治疗药物培美曲塞和获批磷酸二酯酶-5（PDE 5）抑制剂治疗非小细胞肺癌（NSCLC）的新型药物疗法。培美曲塞与获批的PDE 5抑制剂协同作用，在体外和体内杀死NSCLC细胞。西地那非（万艾可）、伐地那非（艾力达）和他达拉非（希爱力）是PDE 5的抑制剂，可调节cGMP水平并诱导一氧化氮合酶（NOS）表达，增加肿瘤细胞中NO和ONOO-水平。培美曲塞被开发为胸苷酸合成酶的抑制剂，但随后显示其抑制酶AICART。目标1。详细确定PDE 5抑制剂和培美曲塞相互作用杀死NSCLC细胞的分子机制。我们假设PDE 5抑制剂和培美曲塞治疗相互作用，消除AKT、mTOR和p70 S6 K活性，导致毒性自噬水平升高，c-FLIP-s、BCL-XL和MCL-1表达降低。我们假设PDE 5抑制剂和培美曲塞治疗增加PERK/eIF 2 α磷酸化，也导致c-FLIP-s、MCL-1和BCL-XL表达抑制。这导致更高的游离BAX和巴克（活性）和升高水平的未束缚的Beclin 1，其也促进毒性自噬的诱导。我们将确定西地那非克服NSCLC细胞培美曲塞耐药的机制。我们还假设PDE 5抑制剂：（a）增加使mTOR和p70 S6 K失活的iNOS水平;（B）抑制促进死亡受体CD 95酪氨酸磷酸化、配体非依赖性受体活化和DISC形成的PTK活性。目标二。使用动物模型确定PDE 5抑制剂是否增强培美曲塞在NSCLC肿瘤中的疗效。我们将利用非小细胞肺癌的转基因和无胸腺动物模型。目的2将使用具有人肺癌细胞系的动物模型和肺癌的小鼠遗传模型来验证我们与NSCLC的体外数据。我们将确定西地那非/培美曲塞治疗是否在体内使肺癌肿瘤化学增敏（对顺铂）。

DESCRIPTION (provided by applicant): In the this application we propose to build on our experience with Pemetrexed (NCT01450384) and develop a novel drug therapy for non-small cell lung carcinoma (NSCLC) combining the standard of care drug Pemetrexed with approved phosphodiesterase-5 (PDE5) inhibitors. Pemetrexed synergizes with approved PDE5 inhibitors to kill NSCLC cells in vitro and in vivo. Sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) are inhibitors of PDE5, which regulate cGMP levels and induce expression of nitric oxide synthase (NOS), increasing NO and ONOO- levels in tumor cells. Pemetrexed was developed as an inhibitor of thymidylate synthase but which was subsequently shown to inhibit the enzyme AICART. Aim 1. Determine in detail the molecular mechanisms by which PDE5 inhibitors and Pemetrexed interact to kill NSCLC cells. We hypothesize that PDE5 inhibitor and Pemetrexed treatment interact to abolish AKT, mTOR and p70 S6K activities leading to elevated levels of toxic autophagy and reduced expression of c-FLIP-s, BCL-XL and MCL-1. We hypothesize that PDE5 inhibitor and Pemetrexed treatment increases PERK/eIF2α phosphorylation also leading to suppression of c-FLIP-s, MCL-1 and BCL-XL expression. This results in higher free BAX and BAK (activity) and elevated levels of untethered Beclin1 which also facilitates the induction of toxic autophagy. We will determine the mechanisms by which sildenafil overcomes Pemetrexed resistance in NSCLC cells. We also hypothesize that PDE5 inhibitors: (a) increase iNOS levels which inactivates mTOR and p70 S6K and; (b) inhibit PTPase activity promoting death receptor CD95 tyrosine phosphorylation, ligand independent receptor activation and DISC formation. Aim 2. Determine using animal models whether PDE5 inhibitors enhance the therapeutic efficacy of Pemetrexed in NSCLC tumors. We will make use of transgenic and athymic animal models of NSCLC. Aim 2 will validate our in vitro data with NSCLCs using animal models with human lung cancer cell lines and mouse genetic models of lung cancer. We will determine whether sildenafil/Pemetrexed treatment chemo-sensitizes lung cancer tumors in vivo (to cisplatin).