Resistance Mechanisms in ROS1-Fusion-Driven Malignancies

ROS1融合驱动的恶性肿瘤的耐药机制

• 批准号: 10321897
• 负责人: Sudarshan Rajan Iyer
• 金额: $ 5.18万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-16 至 2025-01-15
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10321897
• 关键词: Address; Affinity; Appearance; Attention; Binding; Biological Assay; Biological Models; Bypass; C-terminal; Cancer Patient; Cell Line; Cell Survival; Cell fusion; Cells; Clinical; Data; Deaminase; Down-Regulation; Drug Design; Drug resistance; Engineering; Epithelial Cells; Future; Gene Expression; Gene Expression Profiling; Gene Fusion; Generations; Genes; Genomic Instability; Glioblastoma; Human; In Vitro; Incidence; Laboratories; Malignant Neoplasms; Membrane; Memorial Sloan-Kettering Cancer Center; Mitogen-Activated Protein Kinases; Molecular; Mutagenesis; Mutate; Mutation; Neoplastic Cell Transformation; Non-Small-Cell Lung Carcinoma; Orphan; PI3K/AKT; Pathway interactions; Patients; Phospho-Specific Antibodies; Phosphotransferases; Play; Point Mutation; Protein Overexpression; RNA; ROS1 gene; Receptor Protein-Tyrosine Kinases; Recurrence; Research; Resistance; Role; Signal Pathway; Signal Transduction; Structure; Symptoms; TP53 gene; Testing; Therapeutic; Therapeutic Intervention; Time; Tumor Burden; Tumor Suppressor Proteins; Tyrosine Kinase Inhibitor; Western Blotting; base; cancer cell; cancer genome; cell transformation; clinical implementation; combat; crizotinib; design; differential expression; experience; gain of function; improved; in vivo; inhibitor; inhibitor therapy; kinase inhibitor; knock-down; next generation; novel; oncogene addiction; overexpression; patient derived xenograft model; resistance mechanism; small molecule; targeted treatment; transcription factor; treatment strategy; tumor; tumorigenic

Project Summary Gene fusions of the orphan receptor tyrosine kinase, ROS1, are expressed in a range of malignancies. My lab and other labs have demonstrated that ROS1 gene fusions drive neoplastic transformation of cells in vitro and are tumorigenic in vivo when concurrent with loss of tumor suppressor (TP53). It is thought that these gene fusions transform cells via uncontrolled ROS1 kinase activity. Importantly, clinical implementation of the first- generation ALK and ROS1 tyrosine kinase inhibitor (TKI), crizotinib, has resulted in significant reduction of tumor burden in patients with ROS1-fusion positive tumors. However, the efficacy of crizotinib treatment is often short-lived as resistance to the drug emerges after a period of time. Therefore, ongoing research efforts will be required to discover second-line or combination therapeutic options. Clinical resistance to crizotinib treatment has taken on two forms: 1) aberrations in alternate signaling pathways that compensate for any loss in ROS1 kinase signaling (“bypass pathway aberrations”) and 2) loss of TKI potency due to point mutations in the ROS1 kinase domain. While both forms of resistance are equivalent in terms of incidence, little attention has been provided towards understanding bypass pathway aberrations. Notably, a patient that our collaborators at Memorial Sloan Kettering Cancer Center (MSKCC) are treating has stopped responding to crizotinib therapy for ROS1-fusion positive non-small-cell lung cancer after initially seeing tumor regression. Sequencing of the crizotinib-resistant tumor found a copy-number amplification (CNA) in the transcription factor, MYC, that was absent in the initial tumor. I hypothesize that CNA of MYC represents a bypass pathway aberration that has reduced the efficacy of crizotinib treatment in this patient and that this phenomenon can occur in other tumors. To study this, I will 1) reversibly perturb MYC in cells derived from the patient tumor to determine if ROS1-TKI sensitivity is restored and 2) overexpress MYC in a crizotinib- sensitive, ROS1-fusion expressing human broncho-epithelial cell line to observe if ROS1-TKI resistance appears. Unlike bypass pathway aberrations, much research has been conducted to characterize ALK and ROS1 kinase point mutations that confer resistance to crizotinib. This has aided the design of second-generation ALK/ROS1- TKIs like lorlatinib that can bind to the ROS1 kinase domain even in the presence of these mutations. However, I hypothesize that resistant point mutations will develop towards the new TKIs and that predicting them will inform future drug design. To study this, I will perform a forward mutagenesis screen in a lorlatinib-sensitive ROS1-fusion cell line to identify mutations in ROS1 that confer resistance to lorlatinib. Taken together, achieving the objectives of this project will: 1) discover a bypass pathway aberration that causes resistance to the ALK/ROS1-TKI, crizotinib, and 2) identify ROS1 point mutations that confer resistance to a next-generation ROS1-TKI, lorlatinib. This will help combat future ROS1-TKI resistance in patients.

项目摘要 孤儿受体酪氨酸激酶ROS1的基因融合在一系列恶性肿瘤中表达。我的实验室 其他实验室表明，ROS1基因融合驱动细胞在体外和 当同时发生肿瘤抑制因子时，体内是肿瘤的（TP53）。人们认为这些基因 融合通过不受控制的ROS1激酶活性转化细胞。重要的是，首先的临床实施 Crizotinib代ALK和ROS1酪氨酸激酶抑制剂（TKI）导致显着降低 ROS1融合阳性肿瘤患者的肿瘤燃烧。但是，克罗唑替尼治疗的效率是 一段时间后，由于对药物的抵抗而出现了短暂的寿命。因此，正在进行的研究工作 需要发现二线或组合疗法选择。 对克唑替尼治疗的临床抗性已采用两种形式：1）替代信号中的畸变 补偿ROS1激酶信号传导中任何损失的途径（“旁路途径差”）和2） 由于ROS1激酶结构域中的点突变引起的TKI效力。虽然两种形式的电阻都是等效的 在事件方面，很少有人注意理解旁路途径畸变。 值得注意的是，我们在纪念Sloan Kettering癌症中心（MSKCC）的合作者正在治疗的患者 最初对ROS1融合阳性非小细胞肺癌的克佐替尼治疗作出反应 看到肿瘤回归。抗crizotinib耐药性肿瘤的测序发现了拷贝数放大 （CNA）在转录因子MYC中，在初始肿瘤中不存在。我假设MYC的CNA 代表旁路途径的畸变，该途径降低了该患者中克唑替尼治疗的效率 这种现象可能发生在其他肿瘤中。为了研究这一点，我将1）可逆性地扰动MYC在衍生的细胞中 从患者肿瘤中确定ROS1-TKI敏感性是否恢复，2）在crizotinib-中过表达myc 表达人支气管上皮细胞系的敏感的，ROS1融合，观察ROS1-TKI抗性是否抗性 出现。 与旁路途径的畸变不同，已经进行了许多研究以表征ALK和ROS1激酶 会议的点突变，使抗crizotinib的抵抗力。这有助于第二代ALK/ROS1-的设计 TKIS这样的TKI，即使在存在这些突变的情况下，也可以与ROS1激酶结构域结合。然而， 我假设抗性点突变将发展为新的TKI，并且预测它们将会 告知未来的药物设计。为了研究这一点，我将在洛拉替尼敏感的情况下执行正向诱变屏幕 ROS1融合细胞系以鉴定ROS1中的突变，即对洛拉替尼的抗性。 两者合计，实现该项目的目标将：1）发现旁路途径的畸变 引起对ALK/ROS1-TKI，Crizotinib的抗性 到下一代ROS1-TKI，Lorlatinib。这将有助于抵抗患者未来的ROS1-TKI耐药性。