A novel regimen to target both pancreatic cancer K-ras and antiapoptotic proteins

摘要 R03试验项目的目标是演示一种创新的联合治疗的概念验证 针对K-ras突变和一个或多个异常表达的胰腺癌的治疗方案 抗细胞凋亡蛋白。K-ras癌基因突变和主要抗细胞凋亡蛋白的异常表达。 Survivin，Mcl-1，XIAP，cIAP2)在胰腺癌的发生和发展中起重要作用 侵袭性(治疗耐药、转移和复发)。观察到K-ras功能增益突变 在90%的胰腺癌患者中。突变K-ras基因沉默诱导细胞凋亡和抑制 胰腺癌细胞生长、侵袭性、恶性肿瘤形成和异种移植瘤生长。然而， 目前尚无针对胰腺癌K-ras突变的有效靶向治疗方法。用一本小说 K-ras突变细胞与正常细胞的筛选方法 鉴定了药用植物Amoora rohituka，并使用半合成方法生成了50多个衍生物 来自15支安打的接近。然后使用K-ras突变细胞对这些化合物进行重新筛选，与正常细胞相比 细胞。AMR-Me和AMR-MeOAc是选择性地抑制K-ras的最有效的化合物 突变细胞。我们先前的研究表明，AMR-Me针对K-ras途径，每天3 mg/kg用于治疗 对小鼠进行28天的治疗没有显示出明显的毒性，同时它延长了白血病小鼠的存活时间。我们计划 将AMR-MeOAc(最佳选择性)与我们的新化合物FL118结合，后者选择性地抑制Survivin， MCL-1、XIAP和CIAP2，用于测试这种新的联合靶向治疗方案。它之前已经 研究表明，K-ras沉默与吉西他滨联合应用可显著减少小鼠的肿瘤体积 与单独使用任何一种药物相比。因此，我们假设，对两个突变的K-ras的抑制 新药AMR-MeOAc和FL118的主要抗凋亡蛋白将导致 显著增强对胰腺癌细胞和肿瘤生长的诱导凋亡和抑制作用 而不是任何一种药物单独产生的抑制作用。本项目提出了以下三个具体目标。 目的1：观察AMR-MeOAc在小剂量FL118存在或不存在的情况下对胰腺的作用 癌细胞的生长、凋亡以及相关信号通路中蛋白质的调控。 目的2：在人体内测定AMR-MeOAc在小剂量FL118存在或不存在的情况下的疗效 胰腺癌细胞系来源的异种移植模型。 目的3：确定AMR-MeOAc在小剂量FL118存在或不存在的情况下的疗效 异种移植直接来源于患者胰腺癌组织。 伴有K-ras功能增强突变和一种或多种抗凋亡药物异常表达的胰腺癌 蛋白质(Survivin、Mcl-1、XIAP、cIAP2)很难治疗。该项目可能会开发出一种新颖的、有针对性的 有效控制这一具有挑战性和难以治疗的癌症的组合策略。

Abstract The goal of this R03 pilot project is to demonstrate a proof of concept for an innovative combination treatment regimen designed to target pancreatic cancer with K-ras mutations and aberrant expression of one or more antiapoptotic proteins. K-ras oncogenic mutations and aberrant expression of major antiapoptotic proteins (e.g. survivin, Mcl-1, XIAP, cIAP2) in pancreatic cancer heavily contribute to pancreatic cancer development and aggressiveness (treatment resistance, metastasis, and relapse). Gain-of-K-ras-function mutations is observed in >90% of pancreatic cancer patients. Genetic silencing of mutated K-ras induces apoptosis and inhibits pancreatic cancer cell growth, invasiveness, malignant tumor formation, and xenograft tumor growth. However, there are no effective targeted therapies available for pancreatic cancer K-ras mutations. Using a novel screening approach with K-ras mutant cells versus normal cells, fifteen chemical constituents from the medicinal plant Amoora rohituka were identified, and over 50 derivatives were generated using semi-synthetic approaches from the 15 hits. These compounds were then rescreened using K-ras mutant cells versus normal cells. AMR-Me and AMR-MeOAc were identified as the most potent compounds selectively against the K-ras mutant cells. Our previous studies indicated that AMR-Me targets the K-ras pathway, and that 3 mg/kg daily for 28-day treatment of mice shows no clear toxicity, while it extends leukemia mouse survival. We plan to combine AMR-MeOAc (best selectivity) with our novel compound, FL118, which selectively inhibits survivin, Mcl-1, XIAP, and cIAP2, for testing this novel combinational-targeted treatment regimen. It has previously been shown that combination of K-ras silencing with gemcitabine dramatically reduces tumor volumes in mice compared with either single agent alone. Therefore, we hypothesize that inhibition of both mutated K-ras and the major antiapoptotic proteins with the novel agents AMR-MeOAc and FL118 would lead to a strikingly enhanced induction of apoptosis and inhibition of pancreatic cancer cell and tumor growth than the inhibition from either agent alone. The following three specific aims are proposed in this project. Aim 1: Determine the efficacy of AMR-MeOAc in the presence or absence of low dose FL118 on pancreatic cancer cell growth, apoptosis, and modulation of proteins in the relevant signaling pathways. Aim 2: Determine the efficacy of AMR-MeOAc in the presence or absence of low dose FL118 using human pancreatic cancer cell line-derived xenograft models. Aim 3: Determine the efficacy of AMR-MeOAc in the presence or absence of low dose FL118 against xenografts directly derived from patient pancreatic cancer tissues. Pancreatic cancer with K-ras gain-of-function mutations and aberrant expression of one or more antiapoptotic proteins (survivin, Mcl-1, XIAP, cIAP2) is hard to treat. This project may develop a novel and targeted combination strategy to effectively control this challenging and difficult-to-treat cancer.