Understanding and targeting mutant splicing factors in pancreatic cancer

胰腺导管腺癌是一种高度侵袭性和致命性的癌症，对 目前可用的治疗方法。值得注意的是，我们发现PDAC对一系列 针对RNA剪接的治疗。然而，尚不清楚RNA剪接中的变化是如何驱动PDAC的 肿瘤发生或影响治疗反应。因此，鉴定异常的RNA剪接在 PDAC的肿瘤发生可能为PDAC提供新的治疗靶点。我们的长期目标是识别， 设计和测试针对PDAC等高侵袭性肿瘤的新型机械性靶向疗法。这个 这项建议的主要目的是表征RNA剪接因子突变在PDAC中的作用 发病机制及治疗反应。最近，我们发现最常见的功能增益驱动器 在50%的PDAC中发现的突变(突变的KRAS和P53)通过改变的RNA协同作用 拼接。虽然90%的PDAC病例存在突变的KRAS，但只有50%的患者同时存在突变的P53。我们 在数百个带有注释的PDAC突变中进行了排他性分析，并确定了两个 突变剪接因子SF3B1和RBM10，与突变的KRAS共出现，但不与突变的KRAS共出现 P53和P53之间是相互排斥的。此外，我们的概念验证研究使用新的 产生的基因工程小鼠模型、寡聚疗法和RNA剪接抑制剂证明 RNA剪接是一种治疗靶点。我们的中心假设是持续的RNA剪接缺陷， SF3B1和RBM10突变的下游是KRAS介导的一种必要的适应机制 致瘤性，代表了PDAC的治疗靶点。我们的目标是1)确定异常RNA的作用 剪接在PDAC肿瘤发生中的作用，2)确定胰腺的功能和纠正RNA剪接缺陷 3)评价突变RNA剪接因子对剪接体治疗效果的影响 抑制剂和化疗药物。我们的预期结果包括识别1)有多反常 RNA剪接是主要癌症驱动事件的基础，2)为我们新产生的新的治疗靶点 寡头疗法或小分子抑制剂，以及3)以前被忽视的癌症如何 通过多个突变汇聚到一个共同的机制函数来进化。我们将使用创新的 新产生的共表达KRAS和剪接因子突变的基因工程小鼠模型 胰腺导致类似患者肿瘤的自体PDAC，我们将采用新的 用于识别和纠正RNA剪接缺陷的计算和遗传生物技术。这些结果将 揭示PDAC发病所需的一种基本而新颖的非突变机制：改变的RNA 拼接。这将为未来治疗PDAC的方法提供坚实的基础，这将显著影响 个性化治疗和患者结果。这项研究与NCI推进的使命直接一致 对癌症的驱动因素和目标的科学知识，以改善患者的生活。

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and lethal cancer that is resistant to currently available therapies. Notably, we discovered that PDACs are exquisitely susceptible to a range of therapies directed at RNA splicing. However, it is unknown how alterations in RNA splicing drive PDAC tumorigenesis or impact therapeutic responses. Thus, identification of the role of aberrant RNA splicing in PDAC tumorigenesis could reveal novel therapeutic targets for PDAC. Our long-term goal is to identify, design, and test novel mechanistic-based targeted therapies for highly aggressive tumors such as PDAC. The main objective of this proposal is to characterize the role of RNA splicing factor mutations in PDAC pathogenesis and treatment response. Recently, we identified that the most common gain-of-function driver mutations found in 50% of PDACs (mutant KRAS and p53) synergize and cooperate through altered RNA splicing. While >90% of PDAC cases harbor mutant KRAS, only 50% co-occur with mutant p53. We performed mutual exclusivity analysis among hundreds of annotated mutations in PDACs and identified two mutant splicing factors, SF3B1 and RBM10, that co-occur with mutant KRAS but do not co-occur with mutant p53 and are mutually exclusive between each other. Additionally, our proof-of-concept studies using newly generated genetically engineered mouse models, oligo-therapy and RNA splicing inhibitors demonstrated that RNA splicing is a therapeutic target. Our central hypothesis is that persistent RNA splicing defects, downstream of SF3B1 and RBM10 mutations, are a required adaptive mechanism for KRAS-mediated tumorigenicity and represent a therapeutic target for PDAC. We aim to 1) determine the role of aberrant RNA splicing in PDAC tumorigenesis, 2) identify the function and correct RNA splicing defects in pancreatic cancer, and 3) evaluate the impact of mutant RNA splicing factors on the therapeutic efficacy of spliceosome inhibitors and chemotherapeutic agents. Our expected outcomes include identification of 1) how aberrant RNA splicing underlies major cancer-driving events, 2) novel therapeutic targets for our newly generated oligo-therapy or small molecule inhibitors, and 3) a previously overlooked mechanism for how cancer can evolve through multiple mutations converging at a common mechanistic function. We will use innovative newly generated genetically engineered mouse models co-expressing KRAS and splicing-factor mutations in the pancreas leading to autochthonous PDAC resembling patient tumors, and we will employ novel computational and genetic biotechnologies to identify and correct RNA splicing defects. These results will uncover a fundamental, yet novel non-mutational mechanism required for PDAC pathogenesis: altered RNA splicing. This will provide a strong basis for future approaches to treat PDAC, which would significantly impact personalized therapies and patient outcomes. This research directly aligns with NCI’s mission to advance scientific knowledge of drivers and targets of cancer to improve patient’s lives.