Project 2: Building Combinatorial Therapies against KRAS-mutant Colorectal and Pancreatic Cancer

摘要 KRAS基因在~90%的胰腺癌(PDAC)和~50%的结直肠癌(CRC)中发现激活突变 癌症。然而，旨在对抗或消除KRAS信号的治疗策略仍然存在 不成功。冗余的信号通路和复杂的实体肿瘤微环境是导致肿瘤死亡的关键障碍 目前KRAS的目标努力。大多数针对KRAS的常规药物测试通常使用常规 缺乏临床相关性和生物异质性的细胞系系统，因此在患者中失败。更多 最近，患者衍生的模型，包括原代细胞培养，细胞器或球体已被部署在 设计用于识别有效的联合疗法的大屏幕。由于患者派生的模型更具临床意义 代表性的、主要的单一代理或组合显示出更高的翻译成功可能性。我们的 方法的长期目标是建立和测试使用患者来源的异种移植物(PDX)和 更有效地检测药物敏感性的体外肿瘤组织培养试验。使用这种体外方法，我们测试了 36种药物组合与10种PDAC PDX肿瘤对照，以确定证明 协同效应。这些组合包括MEK抑制剂和多激酶抑制剂、孙替尼或 CDK4/6抑制剂。在我们的CRC PDX中也出现了使用MEK-CDK4/6组合的协同抗癌活性 这些模型已经转化为正在进行的临床试验。我们的初步研究和正在进行的临床试验为 在大量的PDX队列中进一步测试这些组合的充分理由。在拟议的研究中，我们的目标是： 1)通过体内PDX试验确定基于MEK抑制剂的组合的有效性；2) 建立和鉴定参加MEK和CDK4/6联合临床试验的患者的PDX 3)识别有反应的肿瘤的生物标记物，并探讨耐药机制。 使用临床相关的患者衍生模型系统预测的研究中铅组合的识别 在未来的临床研究中有更高的成功机会。此外，所有建议的测试试剂都已获准使用。 抗癌或正在进行临床试验评估。因此，这些努力很有可能将 将迅速转化为临床，并迅速使PDAC和CRC患者受益。

Abstract Activating mutations of the KRAS gene are found in ~90% of pancreatic (PDAC) and ~50% of colorectal (CRC) cancers. However, therapeutic strategies designed to counter or extinguish KRAS signaling remain unsuccessful. Redundant signaling pathways and a complex solid tumor microenvironment are key barriers to current KRAS targeting efforts. Most conventional drug testing targeting KRAS has commonly used conventional cell line systems that lack clinical relevance and biological heterogeneity and thereby failed in patients. More recently, patient-derived models, including primary cell cultures, organoids or spheroids have been deployed in large screens designed to identify effective combination regimens. Since patient-derived models more clinically representative, lead single agents or combinations are exhibiting a higher likelihood of translational success. Our approach long-term goal is to establish and test agents using patient-derived xenografts (PDX) coupled with an ex-vivo tumor tissue culture assay that more effectively tests drug sensitivity. Using this ex-vivo method we tested 36 drug combinations against a panel of 10 PDAC PDX tumors to identify drug combinations that demonstrate synergistic effects. These combinations include, MEK inhibitors along with multi-kinase inhibitor, suntinib, or CDK4/6 inhibitors. Synergistic anticancer activity using MEK-CDK4/6 combinations also occurs in our CRC PDX models that have translated to an ongoing clinical trial. Our preliminary studies and ongoing clinical trial provide a strong rationale to further test these combinations in large cohorts of PDXs. In the proposed study, we aim to: 1) determine the effectiveness of the MEK inhibitor-based combinations through in vivo PDX trials; 2) establish and characterize PDXs from patients enrolled in a clinical trial that combines MEK and CDK4/6 inhibitors; and 3) identify biomarkers of responding tumors and explore the mechanisms of resistance. The identification of lead combinations in studies using clinically relevant patient-derived model systems predicts a higher chance of success in future clinical studies. In addition, all proposed test agents are approved for use against cancer or are being evaluated in the clinical trials. Thus, there is a high probability that these efforts will be quickly translated to the clinic and rapidly benefit PDAC and CRC patients.