Irreversible Inhibtion of Cerebellar Gli Transcription Factors by Cobalt (III) Complexes

钴 (III) 复合物对小脑 Gli 转录因子的不可逆抑制

基本信息

批准号：
10338124
负责人：
Meghan Ward
金额：
$ 2.4万
依托单位：
NORTHWESTERN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-03-01 至 2022-07-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10338124
关键词：
Active Sites Adverse effects Age Alkynes Azides Binding Cancer Etiology Cell Membrane Permeability Cells Child Childhood Malignant Brain Tumor Clinical Trials Cobalt Complex Consensus Sequence Contrast Media Coupled Coupling DNA DNA Binding Domain DNA Structure Developmental Delay Disorders Disease Dose Drosophila genus Drug resistance Effectiveness Embryo Ensure Erinaceidae Excision Family GLI Family Protein Genes Genetic Genetic Transcription Goals Growth Heterogeneity Histology Homologous Gene Human Hybrids Image Impairment In Vitro Individual Injections Investigation Knowledge Label Laboratories Lead Ligand Binding Ligands Magnetic Resonance Imaging Malignant - descriptor Membrane Proteins Methods Mission Modeling Mutation Nanoconjugate Outcome Pathway interactions Patients Physiological Property Proteins Quality of life Research Route SHH gene Scheme Schiff Bases Series Site Specificity Subgroup Survival Rate System Temperature United States National Institutes of Health Zinc Fingers cancer imaging cancer recurrence chemotherapy effective therapy experience improved in vivo individualized medicine inhibitor interest irradiation kidney cell medulloblastoma medulloblastoma cell line mortality mouse model nanoGold nanoparticle delivery preservation resistance mutation scaffold smoothened signaling pathway stem success transcription factor treatment strategy tumor tumor growth uptake

项目摘要

Aberrant expression of the Hedgehog (Hh) signaling pathway is heavily implicated in the formation and proliferation of a subgroup of medulloblastoma (MB) tumors. MB is predominantly a pediatric brain cancer, with 70% of occurrences appearing in children under the age of 10. The SHH subgroup, driven by Hh signaling, is widely heterogeneous in genetic cause and histology, making effective treatment challenging and resulting in dismal outcomes. Current treatment strategies involve tumor resection, craniospinal irradiation, and chemotherapy, but suffer from short-term and long-term adverse effects. In efforts to inhibit the Hh pathway, research has targeted the protein Smoothened (Smo), but has been stunted by downstream mutations that lead to cancer recurrence with a much higher lethality. Thus, this project seeks to target Gli proteins, which belong to a family of zinc finger transcription factors (TFs) and are the final effectors of the Hh pathway. The Meade lab has developed a series of Cobalt (III)-Schiff base complexes (Co(III)-sb) coupled to TF consensus sequences that specifically and irreversibly inhibit zinc finger TFs of interest. This proposal seeks to reinvent the method for conjugating Co(III)-sb to the Gli consensus sequence to generate Co(III)-Gli, a highly specific and irreversible inhibitor of Gli proteins. This inhibitor will be conjugated to a Gd(III)-labeled gold nanoparticle (AuNP) delivery platform to evaluate and image the effectiveness of Gli inhibition both in vitro and in vivo. The first objective of this proposal is to redesign the synthetic route for coupling DNA to Co(III)-sb. The equatorial ligand scaffold of Co(III)-sb will be functionalized with an alkyne moiety to allow for clickable conjugation to an azide functionalized Gli consensus sequence, generating Co(III)-Gli. This is anticipated to significantly improve yields and scalability from the current conjugation method. The second and third objectives focus on evaluating the potency of Co(III)-Gli against Gli for the inhibition of tumor growth. Co(III)-Gli will be hybridized to a DNA capped AuNP to generate an optimized dehybridization sequence to release the agent at physiological temperature. Co(III)-Gli AuNPs will be labeled with Gd(III) magnetic resonance imaging (MRI) contrast agents to provide a platform for fate mapping the conjugates both in vitro and in vivo. The ability of Co(III)-Gli to inhibit exogenous Gli will be evaluated in vitro using human embryonic kidney cells and in vivo using a murine model that natively develops SHH subtype MB tumors. Co(III)-Gli is anticipated to inhibit Gli with high specificity, resulting in suppressed tumor growth. This project fully aligns with the mission of the NIH both in its short-term and long-term implications. It will further develop knowledge about inhibition of cerebellar Gli transcription factors in the short-term, and generate a platform for enhancing current treatment options for SHH subtype medulloblastoma long-term. The success of this project would present a unique opportunity for improving the survival rate and resulting quality of life for the most malignant childhood brain cancer.

Hedgehog (Hh) 信号通路的异常表达与形成和髓母细胞瘤 (MB) 肿瘤亚组的增殖。 MB 主要是一种儿童脑癌， 70% 的事件出现在 10 岁以下的儿童中。SHH 亚组由 Hh 信号驱动，是遗传原因和组织学存在广泛的异质性，使得有效的治疗具有挑战性并导致惨淡的结果。目前的治疗策略包括肿瘤切除、颅脊髓照射和化疗，但会遭受短期和长期的不良反应。为了抑制 Hh 通路，研究以蛋白质 Smoothened (Smo) 为目标，但因下游突变而受阻导致癌症复发，致死率更高。因此，该项目旨在针对 Gli 蛋白，属于锌指转录因子 (TF) 家族，是 Hh 通路的最终效应子。这 Meade 实验室开发了一系列与 TF 共识偶联的钴 (III)-席夫碱配合物 (Co(III)-sb) 特异性且不可逆地抑制感兴趣的锌指转录因子的序列。该提案旨在重塑将 Co(III)-sb 与 Gli 共有序列缀合生成 Co(III)-Gli 的方法，Co(III)-Gli 是一种高度特异性的和 Gli 蛋白的不可逆抑制剂。该抑制剂将与 Gd(III) 标记的金纳米颗粒结合 (AuNP) 递送平台，用于评估和成像体外和体内 Gli 抑制的有效性。该提案的第一个目标是重新设计 DNA 与 Co(III)-sb 偶联的合成路线。这 Co(III)-sb 的赤道配体支架将用炔部分功能化，以允许可点击与叠氮化物功能化的 Gli 共有序列缀合，生成 Co(III)-Gli。预计这将显着提高当前缀合方法的产量和可扩展性。第二个和第三个目标侧重于评估 Co(III)-Gli 对抗 Gli 抑制肿瘤生长的效力。 Co(III)-Gli 将与 DNA 封端的 AuNP 杂交，生成优化的去杂交序列，以释放剂在生理温度下。 Co(III)-Gli AuNP 将用 Gd(III) 磁共振成像进行标记 (MRI) 造影剂为体外和体内缀合物的命运图谱提供平台。能力 Co(III)-Gli 抑制外源 Gli 的作用将使用人胚胎肾细胞在体外进行评估，并在体内进行评估使用天然产生 SHH 亚型 MB 肿瘤的小鼠模型。 Co(III)-Gli 预计可抑制 Gli 具有高特异性，从而抑制肿瘤生长。该项目的短期和长期影响完全符合 NIH 的使命。它将在短期内进一步发展有关小脑 Gli 转录因子抑制的知识，并且建立一个平台，以增强当前 SHH 亚型髓母细胞瘤长期治疗方案。这该项目的成功将为提高成活率和最终质量提供独特的机会最恶性的儿童脑癌的生命周期。