EGFR T790M-mediated drug resistance in non-small cell lung cancer

EGFR T790M 介导的非小细胞肺癌耐药

• 批准号: 9283338
• 负责人: Pinar Ozden Eser
• 金额: $ 3.16万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9283338
• 关键词: Accounting; Address; Alpha Cell; Biology; CRISPR/Cas technology; Cancer Patient; Cell Line; Cells; Clinic; Clinical; Clinical Trials; Clone Cells; Clustered Regularly Interspaced Short Palindromic Repeats; Codon Nucleotides; Collaborations; Cultured Cells; Detection; Development; Dose; Drug Targeting; Drug resistance; Engineering; Epidermal Growth Factor; Epidermal Growth Factor Receptor; Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor; Erlotinib; Exhibits; Exposure to; Gatekeeping; Gefitinib; Generations; Genetic; Genome engineering; Growth; Heterogeneity; In Vitro; Insulin-Like-Growth Factor I Receptor; Laboratories; Lesion; Malignant Neoplasms; Malignant neoplasm of lung; Mediating; Modeling; Mutation; Non-Small-Cell Lung Carcinoma; Oncogenes; Oncogenic; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Point Mutation; Population; Predisposition; Property; Research; Resistance; Resistance development; Sampling; Secondary to; Signal Pathway; Testing; Translating; Tumor Cell Line; base; clinical decision-making; clinical development; clinical efficacy; clinical investigation; design; drug development; epithelial to mesenchymal transition; established cell line; experimental study; extracellular signal-regulated kinase 3; genome editing; inhibitor/antagonist; insight; kinase inhibitor; mutant; novel; preclinical study; prevent; public health relevance; resistance mechanism; resistance mutation; response; small molecule; standard of care; success; targeted treatment; tumor

DESCRIPTION (provided by applicant): A subset of non-small cell lung cancer (NSCLC) is driven by activating mutations of the epidermal growth factor receptor (EGFR). Mutant EGFR-driven lung cancers respond transiently to targeted therapy with the EGFR kinase inhibitors gefitinib and erlotinib, although the clinical efficacy of these inhibitors is limited by the development of drug resistance. The gatekeeper mutation EGFR T790M is the most prevalent resistance mechanism observed in the clinic, accounting for nearly 60% of drug resistance cases. Here, we propose to assess T790M predisposition and biology, and identify resistance mechanisms that emerge when T790M is targeted with a new class of mutant-selective EGFR inhibitors. The first objective is to study why some patients and cell lines develop EGFR T790M, while others become drug resistant through alternative mechanisms. It is not currently known whether EGFR T790M develops de novo in response to drug treatment, or if it is present at very low levels in treatment-naive tumors and becomes detectable due to a selective advantage conferred by drug treatment. To test these possibilities, treatment-naïve cell lines and patient primary cells known to reproducibly become resistant through T790M will be subcloned and analyzed for T790M resistance before and after drug treatment. Characterizing resistance development in clonal subpopulations of cells will provide insight into the repertoire of resistanc mechanisms within a cell line, and help elucidate why T790M is the dominant resistance mechanism in some cellular contexts. Next, CRISPR-Cas9 genome editing will be used to engineer the T790M mutation into treatment-naive cell lines that become resistant through T790M or alternative resistance mechanisms. This will permit study of the T790M mutation in both endogenous and nonendogenous contexts, separating T790M development from any potential passenger mutations that arise during in vitro or ex vivo generation of drug resistance. The consequences of hindering T790M development or reverting EGFR T790M to the wild type codon (T790) will also be explored. The final aim of the proposed research is to characterize novel mechanisms of resistance to mutant-selective inhibitors that specifically target EGFR T790M, along with activating mutant EGFR. The efficacy of these inhibitors is being investigated in ongoing clinical trials. Modeling resistance to mutant-selective inhibitors using cell lines and patient samples will help predict resistance mechanisms that will emerge in the clinic. Taken together, the proposed experiments will provide insight into EGFR T790M development and treatment. These findings will have immediate implications for our understanding of resistance to targeted therapies, and could guide clinical decision-making, and ultimately prevent the development of drug resistance in patients with EGFR-mutant NSCLC.

描述（由申请人提供）：非小细胞肺癌（NSCLC）的一个亚群是由表皮生长因子受体（EGFR）的激活突变驱动的。突变型EGFR驱动的肺癌对EGFR激酶抑制剂吉非替尼和厄洛替尼的靶向治疗有短暂反应，尽管这些抑制剂的临床疗效受到耐药性发展的限制。守门人突变EGFR T790M是临床观察到的最普遍的耐药机制，占耐药病例的近60%。在这里，我们建议评估T790M易感性和生物学，并确定当T790M被一类新的突变选择性EGFR抑制剂靶向时出现的耐药机制。第一个目标是研究为什么一些患者和细胞系会产生EGFR T790M，而另一些患者和细胞系会通过其他机制产生耐药性。目前尚不清楚EGFR T790M是否会对药物治疗产生新反应，或者它是否在首次治疗的肿瘤中以非常低的水平存在，并由于药物治疗赋予的选择性优势而被检测到。为了测试这些可能性，将对treatment-naïve细胞系和已知通过T790M可重复产生耐药性的患者原代细胞进行亚克隆，分析药物治疗前后的T790M耐药性。描述细胞克隆亚群中的耐药发展将有助于深入了解细胞系内的耐药机制，并有助于阐明为什么在某些细胞环境中T790M是主要的耐药机制。接下来，CRISPR-Cas9基因组编辑将用于将T790M突变设计成未经治疗的细胞系，这些细胞系通过T790M或其他抗性机制产生抗性。这将允许在内源性和非内源性环境下研究T790M突变，将T790M的发展与在体外或离体产生耐药性过程中出现的任何潜在乘客突变分离开来。我们还将探讨阻碍T790M发育或将EGFR T790M还原为野生型密码子（T790）的后果。拟议研究的最终目的是表征特异性靶向EGFR T790M的突变选择性抑制剂的耐药新机制，以及激活突变EGFR。正在进行的临床试验正在调查这些抑制剂的疗效。利用细胞系和患者样本模拟对突变选择性抑制剂的抗性将有助于预测将在临床出现的抗性机制。综上所述，拟议的实验将为EGFR T790M的开发和治疗提供深入的见解。这些发现将直接影响我们对靶向治疗耐药的理解，并可以指导临床决策，最终防止egfr突变的NSCLC患者产生耐药。