Pancreatic Cancer Management by Novel Gene Therapy & Dietary Agents

描述（由申请方提供）：胰腺导管腺癌（PC）是最致命和侵袭性最强的人类恶性肿瘤之一，也是美国癌症相关死亡的第四大常见原因，当疾病局限于器官时，生存率为15%，当出现转移性疾病时，生存率仅为4%。在约90%的PC中，K-ras癌基因突变。理解这种肿瘤的发病机制的一个障碍是缺乏合适的小鼠模型来概括人类的状况。这种障碍现在已经通过小鼠模型的开发而减少，该模型利用胰腺中靶向KrasG 12 D表达和Ink 4a/Arf缺陷的组合来开发胰腺上皮内瘤形成（PanIN），其模拟人类疾病，迅速进展为高度侵袭性和转移性癌症。该模型非常适合设计和测试这种普遍致命的人类恶性肿瘤的新的治疗/预防方法。我们先前克隆了黑色素瘤分化相关基因-7/白细胞介素-24（mda-7/IL-24），这是IL-10相关细胞因子基因家族的一个新成员，具有独特的癌症特异性肿瘤诱导特性。最近的I/II期临床试验证实了其在晚期癌症和黑色素瘤患者中的安全性和有效性。出乎意料的是，在PC细胞中mda-7/IL-24的异位表达在诱导细胞凋亡方面是无效的，因为K-ras诱导的“翻译阻滞”限定了mda-7/IL-24 mRNA与多核糖体的结合.当K-ras表达或其下游MEK 1/MEK 2通路被抑制或应用活性氧（ROS）诱导剂时，mda-7/IL-24 mRNA被转化为蛋白质并诱导凋亡。最近有趣的初步研究表明，膳食单萜，紫苏醇（POH），促进PC细胞中的mda- 7/IL-24的促凋亡作用。这项研究提供了第一个例子之间的协同作用的饮食剂和基因治疗在控制生长的侵略性和目前无法治疗的癌症，如PC。我们目前计划：i。分析Ad.mda-7和POH对一系列突变型和野生型K-ras PC细胞的侵袭和转移的组合作用; ii.阐明Ad.mda-7和POH诱导胰腺癌细胞凋亡的分子机制; iii.在转基因胰腺癌动物模型中研究mda-7/IL-24和POH抑制胰腺癌发生和发展的功效。我们还正在开发一种在胰腺中过表达mda-7/IL-24的复合转基因小鼠，以直接证实原位产生的mda-7/IL-24将与POH合作预防PC的发展。我们提出的研究将为未来的努力提供直接相关的重要信息，这些努力旨在将膳食化合物与新型癌症特异性细胞凋亡诱导细胞因子的有效组合转化为患者，用于PC的化学预防和潜在治疗。公共卫生相关性：黑色素瘤分化相关基因-7/白细胞介素-24（mda-7/IL-24）是一种多营养型肿瘤抑制分子，具有诱导肿瘤细胞凋亡的独特特性。膳食单萜，如紫苏醇（POH）也表现出抗肿瘤特性。本提案描述了饮食剂（POH）和基于腺病毒的基因治疗的组合方法，表达mda-7/IL-24，作为最致命的肿瘤之一胰腺癌的化学预防和治疗方案。

DESCRIPTION (provided by applicant): Pancreatic ductal adenocarcinoma (PC) represents one of the most lethal and aggressive human malignancies and the fourth most common cause of cancer-related deaths in the US with 15% survival when the disease is organ confined, and only 4% when presenting with metastatic disease. In ~90% of PC, the K-ras oncogene is mutated. An obstacle to understanding the pathogenesis of this neoplasm has been the lack of suitable murine models that recapitulate the human condition. This impediment has now been diminished by the development of murine models that utilize a combination of targeted KrasG12D expression in the pancreas and Ink4a/Arf deficiency to develop pancreatic intraepithelial neoplasias (PanINs), which mimic the human disease, progressing rapidly to highly invasive and metastatic cancers. This model is ideally suited for designing and testing novel therapeutic/preventive approaches for this universally fatal human malignancy. We previously cloned melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24), a novel member of the IL-10-related cytokine gene family with unique cancer-specific apoptosis-inducing properties. Recent Phase I/II clinical trials confirm its safety and efficacy in humans with advanced carcinomas and melanomas. Unexpectedly, ectopic expression of mda-7/IL-24 in PC cells is ineffective in inducing apoptosis because of a 'translational block' induced by K- ras that delimits association of mda-7/IL-24 mRNA with polysomes. When K-ras expression or its downstream MEK1/MEK2 pathway is inhibited or a reactive oxygen species (ROS) inducer is applied, mda-7/IL-24 mRNA is converted into protein and apoptosis is induced. Recent intriguing preliminary studies show that a dietary monoterpene, perillyl alcohol (POH), facilitates the apoptosis-promoting effects of mda- 7/IL-24 in PC cells. This study provides a first example of a synergistic interaction between a dietary agent and gene therapy in controlling the growth of an aggressive and currently untreatable cancer, such as PC. We currently plan to: i. Analyze the combinatorial effects of Ad.mda-7 and POH on the invasiveness and metastasis of a series of mutant and wild type K-ras PC cells; ii. Elucidate the molecular mechanisms of apoptosis-induction by Ad.mda-7 and POH; iii study the efficacy of mda-7/IL-24 and POH in inhibiting PC development and progression in transgenic PC animal models. We also are developing a compound transgenic mouse overexpressing mda-7/IL-24 in the pancreas to directly confirm that in situ generated mda-7/IL-24 will cooperate with POH in preventing PC development. The studies we propose will provide important information of direct relevance for future efforts designed to translate into patients an effective combination of dietary compounds with a novel cancer-specific apoptosis- inducing cytokine for the chemoprevention and potentially therapy of PC. PUBLIC HEALTH RELEVANCE: Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) is a pleotrophic tumor suppressor molecule that exhibits the unique property of inducing apoptosis only in cancer cells. Dietary monoterpenes, such as perillyl alcohol (POH) also exhibit anti- tumor properties. The present proposal describes a combinatorial approach of a dietary agent (POH) and adenovirus-based gene therapy, expressing mda-7/IL-24, as chemopreventive and therapeutic regimens for one of the deadliest neoplasms, pancreatic cancer.