Deriving Combinatorial Strategies for Therapy of Pancreatic Cancer

描述（由申请人提供）：驱动胰腺癌发生和发展的细胞自主分子事件是多种多样和复杂的。在这种情况下，确定有效的干预和预防战略似乎是一项艰巨的任务。然而，广泛的证据表明，控制“最小致癌平台”形成的统一原则是驱动增殖和抑制细胞凋亡的核心机制的共同依赖异常调节。在肿瘤发生过程中募集来驱动这些途径的关键蛋白可能代表了异质癌细胞群体的最佳干预目标。我们已经建立了高通量sirna介导的功能丧失分析可以揭示新的关键蛋白，选择性地支持癌细胞与正常上皮细胞的存活。这种方法现在可以在全基因组范围内进行，以对支持胰腺癌细胞存活的分子框架进行公正的综合分析。在这里，我们将结合一个手持阵列的全基因组人类siRNA文库和基于高通量细胞的筛选平台，用于广谱鉴定最佳遗传靶点，以集中开发有效的化疗药物。我们的目标是确定最佳的分子靶点，以帮助指导合理设计新的基于药物的人类胰腺癌组合疗法。我们的直接目标是通过全面鉴定支持治疗难治性人类胰腺癌细胞耐药的基因来推进这一目标。靶向这些基因产物或它们调节的途径的药物将是有效的多药治疗的主要候选者。我们的方法是将全基因组siRNA阵列与经过验证的高通量细胞筛选平台相结合，以鉴定对已知化疗化合物具有增强敏感性的基因靶点。我们的具体目标是：1)确定选择性支持人类胰腺细胞系耐药的分子靶点；2)在胰腺癌原位异种移植模型中验证候选靶点的有效性。我们在这里描述的方法将有助于明确识别胰腺癌细胞暴露于吉西滨或环巴胺后选择性存活所需的关键蛋白，这两种药物分别代表常用但效果较差的当前治疗，而另一种药物在临床前模型中有效，但尚未在人体中进行测试。这些信息将1)指导合理选择可用药物和药物组合，以开发新的干预和/或预防策略，2)帮助确定新的药学上可处理的治疗靶点，其抑制对正常细胞的影响最小。

DESCRIPTION (provided by applicant): The cell autonomous molecular events that drive the initiation and progression of pancreatic cancers are multifarious and complex. This context makes identification of effective intervention and prevention strategies a seemingly daunting task. However, widespread evidence suggests that a unifying principle governing formation of a "minimal oncogenic platform" is the co-dependent aberrant regulation of core machinery driving proliferation and suppressing apoptosis. Linchpin proteins recruited to drive these pathways during tumorigenesis likely represent optimal intervention targets in a heterogeneous population of cancer cells. We have established that high-throughput siRNA-mediated loss-of-function analysis can reveal novel linchpin proteins selectively supporting the survival of cancer cells versus normal epithelia. This approach can now be pursued on a genome-wide scale for an unbiased comprehensive analysis of the molecular framework supporting pancreatic cancer cell survival. Here we will combine an in-hand arrayed genome-wide human siRNA library with high-throughput cell-based screening platforms for broad-spectrum identification of optimal genetic targets for focused development of effective chemotherapeutic agents. Our goal is the identification of optimal molecular targets to help guide rational design of novel combinatorial drug-based therapies for human pancreatic cancer. Our immediate objective is to advance this goal by the comprehensive identification of genes that support drug resistance in treatment-refractory human pancreatic cancer cells. Agents that target these gene products or the pathways they regulate will be prime candidates for effective multi-drug therapies. Our approach is to combine a genome-wide siRNA array with a validated high-throughput cell-based screening platform to identify gene targets that expose enhanced-sensitivity to known chemotherapeutic compounds. Our Specific Aims are: 1) To identify molecular targets selectively supporting drug resistance in human pancreatic cell lines, and 2) To validate the effectiveness of candidate targets within an orthotopic xenograft model of pancreatic cancer. The approach we describe here will facilitate the unambiguous identification of linchpin proteins selectively required for survival of pancreatic cancer cells upon exposure to gemcitibine orcyclopamine, two drugs respectively representing the commonly used but less-than-effective current therapy versus an effective agent in preclinical models yet to be tested in humans. This information will 1) guide rational selection of available drugs and drug combinations for development of new intervention and/or prevention strategies, and 2) help identify novel pharmaceutically tractable therapeutic targets whose inhibition will have minimal impact on normal cells.