Project 3: Mechanisms and therapeutic targeting of NRAS in melanoma

项目3：NRAS在黑色素瘤中的作用机制和治疗靶向

• 批准号: 9074409
• 负责人: ADRIENNE D COX
• 金额: $ 15.2万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-22 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9074409
• 关键词: Address; Alleles; Automobile Driving; Biochemical; Biological; Carcinoma; Cell Line; Cells; Codon Nucleotides; Collaborations; Combined Modality Therapy; Cutaneous Melanoma; Dependence; Dependency; Disease; Etiology; FRAP1 gene; Genetic Screening; Goals; Growth; HRAS gene; Human; Incidence; Individual; KRAS2 gene; Large Intestine Carcinoma; Lead; Learning; MEKs; Malignant Epithelial Cell; Malignant Neoplasms; Malignant neoplasm of pancreas; Melanoma Cell; Membrane; Methodology; Mitogen-Activated Protein Kinases; Molecular; Mus; Mutate; Mutation; Neoplasm Metastasis; Oncogenes; Oncogenic; Outcome; Pancreatic carcinoma; Pathway interactions; Phenotype; Property; Protein Isoforms; Proteins; Proto-Oncogene Proteins c-akt; RALGDS gene; Regulation; Role; Signal Pathway; Signal Transduction; Skin Cancer; System; Therapeutic; Transducers; addiction; base; cell motility; effective therapy; gain of function; innovation; knock-down; leukemia; lung Carcinoma; melanocyte; melanoma; mutant; neglect; novel; novel therapeutics; protein function; subcellular targeting; therapeutic target; tumorigenesis; tumorigenic

ABSTRACT Much remains to be learned about how RAS isoforms differ functionally from each other, and about the impact of specific mutations on each RAS protein. NRAS-mutant melanoma represents both a critical unmet need in terms of efficacious therapeutic options and also an outstanding opportunity to elucidate these functional differences. Although KRAS is the predominant RAS isoform mutated in cancers overall, NRAS is the predominant RAS isoform mutated in malignant melanoma, and whereas mutations at codon 61 are rare in KRAS, they predominate in NRAS. Project 2 has recently demonstrated that Nras Q61R but not G12D could drive melanoma formation in Ink4a-deficient mice. These provocative findings indicate that NRAS Q61R and G12D must activate distinct effectors, and/or activate effectors in a distinct manner. Given the preferential occurrence of NRAS Q61 mutations in melanoma, we propose studies to elucidate the signaling mechanisms that distinguish the roles of Q61- versus G12-mutant NRAS in driving these cancers. We hypothesize that there are structural, biochemical and biological properties distinct from those of the more common G12-mutant KRAS proteins found in lung, colorectal and pancreatic carcinomas. We have also identified an unexpected requirement for both KRAS and HRAS WT forms in NRAS-mutant melanomas. We will investigate effector signaling mechanisms driven by different NRAS mutants, define the requirements for WT isoforms, and leverage both candidate- and unbiased methodologies to identify targets that can lead to novel combination therapies for effective treatment of NRAS-driven melanomas. To address our goals, we propose three aims. In Aim 1, we will elucidate known and unknown effector signaling pathways downstream of cellular NRAS mutated at codon 61 versus codon 12. This Aim will be performed in close collaboration with Project 2, which will focus on structural and biochemical differences in the same panel of NRAS mutants. Projects 1 and 4 will also examine some of the cellular and tumorigenic phenotypes of the same mutations in different RAS isoforms. In Aim 2, we will characterize the requirement for WT RAS isoforms, and determine functional differences in effectors and signaling networks, as well as in transformed growth properties. In Aim 3, we will determine whether the same mechanisms that overcome melanoma addiction to mutant NRAS also overcome dependency on WT RAS isoforms. To do this, we will first interrogate YAP, known to be capable of rescuing addiction to mutant KRAS in carcinomas, and we will next perform a novel functional genetic screen to identify non-YAP mechanisms in an unbiased manner. Collectively, our studies will elucidate a better understanding of the neglected NRAS isoform, characterize functional distinctions among different NRAS mutations, determine relationships between WT and mutant NRAS-driven effector signaling pathways and networks, and identify new directions for novel therapeutic options in NRAS-driven melanoma.

摘要 关于RAS亚型在功能上如何相互区别，以及它们对细胞增殖的影响， 每个RAS蛋白的特定突变。NRAS突变型黑色素瘤代表了 有效的治疗选择，也是一个很好的机会来阐明这些功能 差异尽管KRAS是总体上在癌症中突变的主要RAS同种型，但NRAS是主要的RAS亚型。 恶性黑色素瘤中主要的RAS亚型突变，而在恶性黑色素瘤中密码子61的突变是罕见的。 KRAS在NRAS中占主导地位。项目2最近证明，Nras Q61 R而不是G12 D可以 导致Ink 4a缺陷小鼠的黑色素瘤形成。这些挑衅性的发现表明，NRAS Q61 R和 G12 D必须激活不同的效应器，和/或以不同的方式激活效应器。鉴于优惠 NRAS Q61突变在黑色素瘤中的发生，我们建议研究阐明信号机制 区分Q61与G12突变型NRAS在驱动这些癌症中的作用。我们假设 在结构、生物化学和生物学特性上与更常见的G12-突变体不同 在肺癌、结直肠癌和胰腺癌中发现的KRAS蛋白。我们还发现了一种意想不到的 NRAS突变型黑色素瘤中KRAS和HRAS WT形式的需要。我们将研究效应器 由不同NRAS突变体驱动的信号传导机制，定义了WT亚型的要求， 利用候选方法和无偏方法来确定可导致新组合的目标 用于有效治疗NRAS驱动的黑色素瘤的疗法。为了实现我们的目标，我们提出了三个目标。在 目的1，我们将阐明已知和未知的效应信号通路下游的细胞NRAS 在密码子61和密码子12处发生突变。这一目标将与项目2密切合作， 将集中在同一组NRAS突变体的结构和生化差异。项目1和4将 我还研究了不同RAS中相同突变的一些细胞和致瘤表型 同种型。在目标2中，我们将描述WT RAS亚型的需求，并确定功能性 效应器和信号网络的差异，以及转化的生长特性。在目标3中，我们 确定克服黑色素瘤对突变NRAS成瘾的相同机制是否也克服了 依赖于WT RAS亚型。要做到这一点，我们将首先审问雅普，已知能够拯救 成瘾的突变KRAS在癌症中，我们下一步将进行一种新的功能性遗传筛选，以确定 非YAP机制以公正的方式。总的来说，我们的研究将阐明一个更好的理解 被忽视NRAS亚型，表征不同NRAS突变之间的功能差异，决定 WT和突变NRAS驱动的效应信号通路和网络之间的关系，并确定 NRAS驱动的黑色素瘤新治疗选择的新方向。