DDR2 kinase inhibition in squamous cell lung carcinomas

项目总结(见说明)： 在我们的初步研究中，我们发现，在3%到4%的肺鳞癌中，盘状结构域受体2酪氨酸激酶基因DDR2发生了体细胞突变。DDR2基因敲除可杀死携带DDR2突变的肺鳞状细胞癌细胞。此外，对DDR2突变的肺SCC细胞的治疗作用 酪氨酸激酶抑制剂达沙替尼显著抑制细胞增殖；达沙替尼的作用可通过携带达沙替尼耐药T654M门卫突变的DDR2过表达来挽救。 我们现在的目标是进一步开发DDR2作为肺鳞状细胞癌的治疗靶点。我们的具体目标是与其他项目和共享资源核心合作如下： -特定目的1.我们将使用细胞和动物模型系统表征肿瘤来源的DDR2突变体在肺的基底上皮中的致癌潜力。我们将与Core C(Animal)合作建立转基因小鼠模型，用于肺基底上皮特异性DDR2突变体的表达和肿瘤形成的检测。我们还将在基底肺上皮细胞中表达DDR2突变的mRNA，并检测其致癌作用。这些动物和细胞模型将被用来评估DDR2功能被遗传修饰和小分子抑制剂破坏的影响。 -特定目的2.我们将评估在鳞状肺癌模型中对DDR2抑制剂达沙替尼的耐药机制。为了研究c/S对达沙替尼的抗性，我们将在DDR2中设计和/或筛选达沙替尼抗性等位基因，并测试它们对达沙替尼和其他激酶抑制剂的敏感性。此外，我们还将通过异位表达开放阅读框文库来筛选反式抗性。 -具体目标3.利用生物化学和细胞分析开发有效和选择性的DDR2抑制剂，它们的效果。我们将与核心A(化学)和核心B(结构)合作，优化核心A确定为DDR2突变特异性抑制剂的先导化合物，相对于达沙替尼具有更强的DDR2激酶特异性。这些优化的抑制剂将在肺鳞状细胞癌衍生细胞系以及在AIM 1中开发的细胞和动物模型系统中进行测试，包括设计为对达沙替尼具有抗药性的模型。 通过这些努力，该项目将推动DDR2抑制剂的开发，使其成为治疗肺鳞癌的潜在药物。

PROJECT SUMMARY (See instructions): In our Preliminary Studies, we found that DDR2, the discoidin domain receptor 2 tyrosine kinase gene, is somatically mutated in 3 to 4% of lung squamous cell carcinomas (lung SCC). Knock-down of DDR2 kills lung SCC cells bearing DDR2 mutations. Furthermore, treatment of DDR2-mutant lung SCC cells with the tyrosine kinase inhibitor dasatinib significantiy decreases cell proliferation; the effects of dasatinib are rescued by over-expression of DDR2 bearing the dasatinib-resistant T654M gatekeeper mutation. We now aim to develop DDR2 further as a therapeutic target for lung SCC. Our specific aims are to work with the other Projects and the shared resource Cores as follows: -Specific Aim 1. We will characterize the oncogenic potential of tumor-derived DDR2 mutants in the basal epithelium of the lung using cellular and animal model systems. We will work with Core C (Animal) to generate transgenic mouse models for lung basal epithelium-specific expression of DDR2 mutants and assay for tumor formation. We will also express DDR2 mutant mRNA in basal lung epithelium and test for oncogenic effects. These animal and cellular models will be used to assess the impact of disruption of DDR2 function both by genetic modification and by small molecule inhibitors. -Specific Aim 2. We will evaluate mechanisms of resistance to the DDR2 inhibitor, dasatinib, in squamous lung cancer models. To study c/s resistance to dasatinib, we will engineer and/or select for dasatinib resistance alleles in DDR2 and test their sensitivities to dasatinib and other kinase inhibitors. In addition, we will screen for trans resistance by ectopic expression of open reading frame libraries. -Specific Aim 3. Develop potent and selective inhibitors of DDR2 using biochemical and cellular assays, their effects. We will collaborate with Core A (Chemistry) and Core B (Structure) to optimize lead compounds identified by Core A as mutant-specific inhibitors of DDR2 with greater DDR2 kinase specificity relative to dasatinib. These optimized inhibitors will be tested in both lung SCC-derived cell lines and in the cellular and animal model systems developed in Aim 1, including models engineered to be resistant to dasatinib. Through these efforts, this project will advance the development of DDR2 inhibitors as potential treatments for squamous cell carcinomas of the lung.