A Genetically Tractable Mouse Model for PRKCI-driven Lung Squamous Cell Carcinoma

项目摘要 肺癌是美国癌症死亡的头号原因。非小细胞肺癌 非小细胞肺癌（NSCLC）占肺癌诊断的大多数（80%），分为两种主要亚型， 肺腺癌（LADC）和肺鳞状细胞癌（LUSC）。新的治疗策略靶向 LADC的主要致癌驱动因素已经导致改善的响应率和患者存活率。但由于 缺乏充分表征的、经验证的和可治疗作用的致癌驱动因子，类似的治疗性 LUSC的预付款尚未到位。原代人LUSC的基因组分析显示， LUSC中最普遍的复发性遗传改变是TP 53的同时丢失和拷贝数增加 （CNG）染色体3q 26（>85-90%）。这些基因改变在两种癌前病变中都可以观察到 和早期LUSC，表明它们是LUSC肿瘤发生的早期促进事件。我们以前的研究 已经证明3q 26基因、PRKCI、SOX 2和ECT 2是协同共扩增的， 在功能上协作以维持LUSC细胞的转化表型。PKCι，蛋白质产物， PRKCI直接磷酸化并调节LUSC细胞中S 0X 2和ECT 2的致癌功能。 此外，我们的初步数据表明：1）在正常人中，SOX 2、PRKCI和ECT 2的过表达， 在Trp 53缺失的情况下，足以转化小鼠肺基底干细胞（LBSC），这是一种主要的细胞来源， LUSC，并驱动具有恶性LUSC特征的肿瘤的形成; 2）PKC 1-S 0X 2信号传导激活LUSC的特异性结合。 指定谱系限制性肺鳞状细胞转化的主转录程序; 3）PKC i-ECT 2 信号传导功能通过控制MEK-ERK信号传导增加LUSC细胞的增殖潜力 和增强的核糖体生物发生;和4）具有3q 26 CNG和SOX 2、PRKCI的两种人LUSC细胞系 和ECT 2转化的LBSC对金诺芬（ANF）的生长抑制作用敏感， 本发明还涉及PKC 1抑制剂，以及致癌PKC 1-SOX 2和PKC 1-ECT 2驱动的效应子的小分子抑制剂。 途径包括Hedgehog、WNT、NOTCH、MEK-ERK和rRNA合成。根据这些数据，我们 假设：1）PRKCI、SOX 2和ECT 2代表LUSC协同多基因驱动因子 肿瘤发生;和2）用ANF和PKC i-SOX 2和PKC i-ECT 2的抑制剂的组合治疗 效应子途径将协同抑制LUSC肿瘤的转化生长。这些假设将 通过完成两个相互关联的具体目标进行测试，目的是：1）评估新药物的疗效 靶向致癌性PKC i效应通路的药物组合;和2）表征一种新的遗传- PRKCI驱动的LUSC的易处理小鼠模型。成功完成这些研究将有助于 设计新的治疗策略，以改善LUSC患者的结局。此外，我们的小说 临床相关的基因工程LUSC小鼠模型将增强我们对LUSC生物学的理解， 表征LUSC的发生和从癌前病变进展为恶性LUSC，识别标志物 用于早期LUSC诊断，并开发和测试新的靶向疗法，以改善LUSC的治疗。

Project Abstract Lung cancer is the number one cause of cancer death in the United States. Non-small cell lung cancer (NSCLC), which accounts for the majority (80%) of lung cancer diagnoses, is divided into two major sub-types, lung adenocarcinoma (LADC) and lung squamous cell carcinoma (LUSC). New therapeutic strategies targeting major oncogenic drivers of LADC have led to improved response rates and patient survival. However, due to a lack of well-characterized, validated, and therapeutically-actionable oncogenic drivers, similar therapeutic advances for LUSC have not been forthcoming. Genomic analysis of primary human LUSC reveals that the most prevalent recurrent genetic alterations in LUSC are concurrent loss of TP53 and copy number gains (CNGs) at chromosome 3q26 (>85-90%). These genetic alterations are observed in both precancerous lesions and early-stage LUSC, indicating they are early promotive events in LUSC tumorigenesis. Our previous studies have demonstrated that the 3q26 genes, PRKCI, SOX2 and ECT2 are coordinately co-amplified and functionally collaborate to maintain the transformed phenotype of LUSC cells. PKCι, the protein product for PRKCI, directly phosphorylates and regulates the oncogenic function of SOX2 and ECT2 in LUSC cells. Furthermore, our preliminary data demonstrate that: 1) overexpression of SOX2, PRKCI and ECT2, in the context of Trp53 loss, is sufficient to transform mouse lung basal stem cells (LBSCs), a major cell of origin for LUSC, and drive formation of tumors with malignant LUSC characteristics; 2) PKCι-SOX2 signaling activates a master transcriptional program specifying lineage-restricted lung squamous transformation; 3) PKCι-ECT2 signaling functions to increase the proliferative potential of LUSC cells through control of MEK-ERK signaling and enhanced ribosome biogenesis; and 4) both human LUSC cell lines with 3q26 CNGs and SOX2, PRKCI and ECT2 transformed LBSCs are sensitive to the growth inhibitory effects of Auranofin (ANF), a potent PKCι inhibitor, and to small molecule inhibitors of oncogenic PKCι-SOX2 and PKCι-ECT2 driven effector pathways including Hedgehog, WNT, NOTCH, MEK-ERK and rRNA synthesis. Based on these data we hypothesize that: 1) PRKCI, SOX2 and ECT2 represent cooperative multigenic drivers of LUSC tumorigenesis; and 2) combined treatment with ANF and inhibitors of PKCι-SOX2 and PKCι-ECT2 effector pathways will synergistically inhibit transformed growth of LUSC tumors. These hypotheses will be tested through completion of two interrelated specific aims designed to: 1) evaluate the efficacy of novel drug combinations that target oncogenic PKCι effector pathways; and 2) characterize a novel genetically- tractable mouse model for PRKCI-driven LUSC. Successful completion of these studies will facilitate the design of novel therapeutic strategies to improve outcomes for patients with LUSC. Furthermore, our novel clinically-relevant genetically-engineered LUSC mouse model will enhance our understanding of LUSC biology, characterize LUSC initiation and progression from preneoplastic lesions to malignant LUSC, identify markers for early LUSC diagnosis and develop and test novel targeted therapies for improved treatment of LUSC.