Defining the role of NF1 and SPRED1 loss in melanoma

项目摘要/摘要 在黑色素瘤中，NF1功能缺失突变是仅次于激活的第三大致癌改变 BRAF和NRAS的突变。Ras GTP酶激活蛋白NF1提供来自 MAPK途径通过与质膜上的SPRED1结合而失活RAS-GTP。我们 最近在黑色素瘤中发现了SPRED1的反复失活突变，发生在一种相互 NF1突变失活的排他性模式，与它们的功能重叠一致。停用任何一种 肿瘤抑制因子通常与额外的MAPK激活突变共存，例如激活 基特。我们假设NF1或SPRED1失活可能会降低KIT治疗抑制的效果 在MAPK通路中获得类似的功能改变。这项研究的目的是确定 在NF1或SPRED1丢失和TO设置中发生的额外MAPK激活改变的频谱 确定NF1或SPRED1在黑色素瘤进展和靶向治疗反应中的作用。我们的 中心假说是NF1或SPRED1缺失会增加MAPK信号转导，但完全恶性转化 需要额外的改变才能进入MAPK途径。我们将对合作者的范围进行分类 与NF1或SPRED1失活形成致癌基因对，并验证它们对肿瘤致病的贡献 在体外和体内都有。我们假设，识别致癌基因对和开发治疗策略 这将解决一对中的两个成员，从而改善患者的预后。我们将提供证据证明 这一概念的原理是基于我们的初步数据，即KIT和MEK的双重抑制是协同作用的 对于具有由KIT突变和NF1或SPRED1缺失组成的致癌对的黑色素瘤。我们将测试 基因工程人类黑色素瘤细胞系和小鼠模型的联合治疗。我们还将 调查KIT和SPRED1之间的直接物理相互作用，这可能会导致其他途径 使用KIT或SPRED1突变抑制黑色素瘤。这项工作将为类似的研究提供一个框架 NF1和SPRED1的其他合作者。这项研究具有重要意义，因为它将导致新的治疗方法 有相当数量的黑色素瘤患者目前无法获得靶向治疗。这个 拟议中的研究具有创新性，因为它测试了一种新的假设，即为什么治疗KIT等突变 对黑色素瘤的疗效有限。揭示了复杂的信号通路在 伴有NF1或SPRED1的相当比例的黑色素瘤将对以下患者产生相当大的影响 目前治疗选择有限的黑色素瘤。

Project Summary/Abstract In melanoma, loss of function mutations in NF1 are the third most common oncogenic alteration after activating mutations in BRAF and NRAS. The RAS GTPase-activating protein NF1 provides negative feedback from the MAPK pathway to RAS by binding to SPRED1 at the plasma membrane where it is inactivates RAS-GTP. We recently discovered recurrent inactivating mutations of SPRED1 in melanoma, occurring in a mutually exclusive pattern with inactivating NF1 mutations, consistent with their functional overlap. Inactivation of either tumor suppressor often co-occurs with additional MAPK activating mutations such as activating mutations of KIT. We hypothesize that NF1 or SPRED1 inactivation may reduce the efficacy of therapeutic inhibition of KIT and similar gain of function alterations in the MAPK pathway. The objective of this research is to identify the spectrum of additional MAPK activating alterations that occur in the setting of NF1 or SPRED1 loss and to determine the role of NF1 or SPRED1 in melanoma progression and response to targeted therapies. Our central hypothesis is that NF1 or SPRED1 loss increases MAPK signaling but that full malignant transformation requires additional alterations that feed into the MAPK pathway. We will catalogue the spectrum of cooperators that form oncogenic pairs with NF1 or SPRED1 inactivation and validate their contributions to tumorigenicity both in vitro and in vivo. We hypothesize that identifying oncogenic pairs and developing therapeutic strategies that address both members of a pair will lead to improved outcomes for patients. We will provide proof of principle for this concept by building on our preliminary data that dual inhibition of KIT and MEK are synergistic for melanomas with an oncogenic pair consisting of KIT mutation and NF1 or SPRED1 loss. We will test combination therapies in genetically engineered human melanoma cell lines and mouse models. We will also investigate the direct physical interaction between KIT and SPRED1, which may lead to additional avenues for inhibiting melanomas with KIT or SPRED1 mutations. This work will provide a framework for similar studies for other cooperators of NF1 and SPRED1. This research is significant since it will lead to novel therapies for a significant number of melanoma patients for whom targeted therapies are not currently available. The proposed research is innovative because it tests a novel hypothesis why treatment of mutations such as KIT have limited efficacy in melanoma. Shedding light onto the complex signaling pathway perturbations in the considerable share of melanomas with NF1 or SPRED1 will have a considerable impact for patients with melanomas for which treatment options are currently limited.