Identifying a nodal point for G alpha q signaling in eye disease

确定眼部疾病中 G α q 信号传导的节点

• 批准号: 9006784
• 负责人: DEAN Yaw LI
• 金额: $ 34.08万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9006784
• 关键词: BRAF gene; Binding; Biological Assay; Blood Vessels; Cause of Death; Cell Nucleus; Cell membrane; Choroid; Cutaneous Melanoma; Data; Disease; Eye; Eye Neoplasms; Eye diseases; FZD4 gene; G alpha q Protein; G(q) Alpha; GNAQ gene; Gene Silencing; Genetic Transcription; Glaucoma; Growth; Health; Human; In Vitro; Individual; Liver; Lung; MAP Kinase Gene; Malignant Neoplasms; Mediating; Melanoma Cell; Methods; Molecular Target; Monomeric GTP-Binding Proteins; Mutation; Neoplasm Metastasis; Nodal; Nuclear Translocation; Oncogenic; Organ; Pathway interactions; Patients; Pharmacotherapy; Phospholipase C; Play; Protein Kinase C; Proteins; RNA Interference; Research Personnel; Retina; Role; Running; Signal Pathway; Signal Transduction; Signaling Protein; Structure of lamina episcleralis; Sturge-Weber Syndrome; Testing; Therapeutic; Transcription Factor AP-1; Uveal Melanoma; WNT Signaling Pathway; WNT5A gene; Xenograft Model; Xenograft procedure; base; conjunctiva; drug development; effective therapy; in vivo; in vivo Model; knock-down; malformation; mouse model; small hairpin RNA; small molecule; small molecule inhibitor; therapeutic target; trafficking; tumor; tumorigenesis

DESCRIPTION (provided by applicant): Activating mutations in two Gα proteins of the q class (Gαq), GNAQ and GNA11, are the drivers of oncogenesis in approximately 80% of uveal melanomas. Similar activating mutations of GNAQ are also found in patients with Sturge-Weber syndrome, which can manifest itself as glaucoma and vascular malformations of the conjunctiva, choroid, retina, and episclera. Uveal melanoma is the most common primary ocular tumor, and in approximately 50% of the cases, the tumor will metastasize to other organs, primarily the liver. Once metastasized, the disease is invariably fatal. Activating GNAQ and GNA11 mutations drive uveal melanoma oncogenesis via the control of several recently identified signaling pathways, including phospholipase C-ß/protein kinase C (PLC-ß/PKC) and TRIO-RhoA/Rac1 pathways, which activate MAPK/ERK and YAP to induce AP1- and YAP-TEAD-mediated transcription. However, the mechanism(s) by which Gαq proteins activate multiple downstream pathways has not been completely elucidated. Preliminary data suggest that the small GTPase ARF6 may act as an immediate downstream effector of activated GNAQ/GNA11 to control all of the currently known oncogenic Gαq signaling pathways. Other preliminary data also suggest that Gαq may signal through ARF6 to activate ß-catenin signaling by promoting the relocalization of ß-catenin from the cell membrane to the nucleus where it can mediate gene transcription. Preliminary data also support the in vivo role of ARF6 in uveal melanoma. When ARF6 is silenced in uveal melanoma by shRNA or is inhibited with a small molecule inhibitor, tumor establishment and growth is significantly inhibited in an orthotopic xenograft mouse model. Based on these preliminary data, the following aims will be pursued. In Aim 1, we will investigate whether activated Gαq proteins induce ß-catenin signaling via activation of ARF6 in uveal melanoma. We will employ gene silencing via RNA interference and small molecule inhibition of selected targets to assess intracellular localization, transcriptional activity, and function of ß-catenin in uveal melanoma. In Aim 2, we will elucidate the role of ARF6 in orchestrating known downstream signaling pathways of oncogenic Gαq. The same strategies used in Aim 1 will be employed to determine whether ARF6 acts as an immediate downstream effector of activating GNAQ/GNA11 mutations to control (PLC-ß/PKC) and TRIORhoA/ Rac1 pathways and AP-1 and YAP-TEAD-mediated transcription. In Aim 3, we will assess the in vivo function of ARF6 in tumor establishment and growth by using orthotopic xenograft models of human uveal melanoma. The successful completion of these aims will allow us to determine whether ARF6 plays a critical role in Gq signaling, thus providing a promising therapeutic target for the development of drugs that could be used to treat uveal melanoma and possibly other Gαq-related disorders such as Sturge-Weber syndrome.

描述（由适用提供）：在Q类的两个Gα蛋白（GαQ），GNAQ和GNA11中激活突变是大约80％的紫veal黑色素瘤中肿瘤发生的驱动因素。在Sturge-Weber综合征患者中也发现了类似的GNAQ激活突变，它们可以表现为结膜，脉络膜，视网膜和埃氏菌的青光眼和血管畸形。卵巢黑色素瘤是最常见的原发性眼肿瘤，在大约50％的病例中，肿瘤将转移到其他器官，主要肝脏。一旦转移，这种疾病总是致命的。激活GNAQ和GNA11突变通过控制最近鉴定的信号通路，包括磷脂酶C-β/蛋白激酶C（PLC-β/PKC）和Trio-RhoA/Rac1途径，驱动紫veal黑色素瘤的过度发生，从而激活MAPK/ERK，并诱导AP1-和YAP诱导AP1-和yap-yap-tead-Tead-pead-Tead-Mifiend-siedied-miedied-siedied-miedied-siedied-miedied-siedied-miedied sifdient。但是，机制由 哪种GαQ蛋白激活多个下游途径尚未完全阐明。初步数据表明，小的GTPase ARF6可以充当激活的GNAQ/GNA11的直接下游效应子，以控制所有当前已知的致癌GαQ信号通路。其他初步数据还表明，GαQ可能通过ARF6发出信号，通过促进从细胞膜到核us的重新定位来介导基因转录，从而激活ß-catenin信号传导。初步数据还支持ARF6在卵巢黑色素瘤中的体内作用。当ARF6通过shRNA沉默或用小分子抑制剂抑制ARF6时，在原位异种移植小鼠模型中，肿瘤的建立和生长显着抑制。基于这些初步数据，将追求以下目标。在AIM 1中，我们将研究激活的GαQ蛋白是否通过在卵巢黑色素瘤中激活ARF6诱导β-catenin信号传导。我们将通过RNA干扰和对所选靶标的小分子抑制进行基因沉默，以评估细胞内定位，转录活性和β-catenin在卵巢黑色素瘤中的功能。在AIM 2中，我们将阐明ARF6在策划致癌GαQ的已知下游信号传导途径中的作用。 AIM 1中使用的AIM 1中使用的相同策略将通过使用人肠内肠内黑色素瘤的原位异种移植模型来评估ARF6在肿瘤建立和生长中的体内功能。这些目标的成功完成将使我们能够确定ARF6在GQ信号传导中是否起着关键作用，从而为开发药物提供了有希望的治疗靶标，这些靶标可用于治疗紫veal黑色素瘤以及可能其他与GαQ相关的疾病，以及诸如Sturge-Weber-Weber综合征。