PPP6C Regulation of ERK Signaling in Melanoma

PPP6C 对黑色素瘤中 ERK 信号传导的调节

• 批准号: 9539242
• 负责人: Eunice Cho
• 金额: $ 2.92万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9539242
• 关键词: Anchorage-Independent Growth; Automobile Driving; BRAF gene; Biochemical; Biological Assay; CRISPR/Cas technology; Catalytic Domain; Cell Line; Cells; Clinical; Complex; Cultured Cells; Data; Down-Regulation; Drug resistance; Ensure; Genetic; Genomics; Goals; Growth Factor; In Vitro; In complete remission; Lesion; Light; MEK inhibition; MEKs; Malignant - descriptor; Malignant Neoplasms; Melanoma Cell; Mitogen-Activated Protein Kinases; Molecular; Mutate; Mutation; NF1 gene; Oncogenic; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacology; Phosphoric Monoester Hydrolases; Phosphotransferases; Predisposition; Protein Dephosphorylation; Protein Phosphatase 2A Regulatory Subunit PR53; Regulation; Resistance; Role; Signal Pathway; Signal Transduction; Skin Cancer; Therapeutic; Treatment Efficacy; Work; base; clinical efficacy; exome sequencing; experimental study; genome editing; improved; inhibitor/antagonist; insight; interest; knock-down; loss of function; loss of function mutation; melanocyte; melanoma; member; mouse model; mutant; novel; protein phosphatase 6; response; small hairpin RNA; targeted sequencing; targeted treatment; tumor progression; tumorigenic

PROJECT SUMMARY/ABSTRACT Melanoma, the deadliest form of skin cancer, is characterized by aberrant hyperactivation of the ERK mitogen- activated protein kinase (MAPK) signaling pathway. Inhibitors of BRAF and MEK, both members of this pathway, have shown clinical efficacy and are used in combination to treat BRAF mutant melanoma, the most common melanoma genomic subtype. However, not all BRAF mutant melanomas respond to these inhibitors, and those that do respond eventually acquire resistance. Better understanding the molecular mechanisms underlying the response and resistance to BRAF and MEK inhibitors will bring us closer to developing durable therapeutic strategies. The main goal of this project is to establish a novel regulatory role for PPP6C, the catalytic subunit of protein phosphatase 6 (PPP6C), in the ERK signaling network. This will allow for understanding how observed genetic lesions in PPP6C alter this oncogenic signaling pathway, likely driving malignant transformation as well as drug resistance in melanoma. Our interest in PPP6C is based on 1) preliminary work observing downregulation of PPP6C promotes resistance to MEK inhibition and increases ERK activation and 2) whole exome and targeted sequencing projects identifying PPP6C is mutated in 7-12% of melanomas. This proposal will examine the effects of PPP6C silencing on ERK activation and inhibitor sensitivity across a panel of melanoma patient-derived cells to confirm a role for PPP6C in regulating ERK signaling. The specific signaling mechanisms underlying PPP6C regulation of ERK signaling will be determined by cellular and biochemical approaches investigating how PPP6C directly or indirectly regulates MEK activation. Regulation of ERK signaling and MEK/BRAF inhibitor susceptibility by cancer-associated PPP6C mutations will be examined in cultured cells and in a mouse model of melanoma. To assess the tumorigenic potential of PPP6C loss, PPP6C knockdown melanocytes will be evaluated for growth factor independent proliferation and anchorage independent growth. The findings from these studies will provide insight into how to optimize the use of clinical MEK and BRAF inhibitors in melanoma and identify opportunities to improve the efficacy of targeted therapies.

项目概要/摘要 黑色素瘤是最致命的皮肤癌，其特征是 ERK 丝裂原异常过度激活 激活蛋白激酶（MAPK）信号通路。 BRAF 和 MEK 的抑制剂，均为该成员 途径，已显示出临床疗效，并联合用于治疗 BRAF 突变黑色素瘤，这是最 常见黑色素瘤基因组亚型。然而，并非所有 BRAF 突变黑色素瘤都对这些抑制剂有反应， 那些做出反应的人最终会遭到抵制。更好地理解分子机制 对 BRAF 和 MEK 抑制剂的反应和耐药性的潜在研究将使我们更接近开发持久的 治疗策略。该项目的主要目标是为 PPP6C 建立一个新颖的监管角色，即 ERK 信号网络中蛋白磷酸酶 6 (PPP6C) 的催化亚基。这将允许 了解观察到的 PPP6C 基因损伤如何改变这一致​​癌信号通路，可能驱动 黑色素瘤的恶性转化和耐药性。我们对 PPP6C 的兴趣基于 1) 初步工作观察 PPP6C 的下调促进对 MEK 抑制的抵抗并增加 ERK 激活和 2) 全外显子组和靶向测序项目确定 PPP6C 发生 7-12% 突变 黑色素瘤。该提案将研究 PPP6C 沉默对 ERK 激活和抑制剂的影响 一组黑色素瘤患者来源的细胞的敏感性，以确认 PPP6C 在调节 ERK 中的作用 发信号。 PPP6C 调节 ERK 信号传导的具体信号传导机制将被确定 通过细胞和生化方法研究 PPP6C 如何直接或间接调节 MEK 激活。癌症相关 PPP6C 对 ERK 信号传导和 MEK/BRAF 抑制剂敏感性的调节 将在培养细胞和黑色素瘤小鼠模型中检查突变。评估致瘤性 PPP6C 丢失的可能性，将评估 PPP6C 敲低黑素细胞的生长因子独立性 增殖和锚定独立生长。这些研究的结果将提供关于如何 优化临床 MEK 和 BRAF 抑制剂在黑色素瘤中的使用，并寻找改善的机会 靶向治疗的疗效。