Prodrugs targeting norepinephrine transporter for dual-selective therapy of refractory neuroblastoma

摘要 该项目重点关注具有双重药理选择性的前药的设计和评价， 将分子靶向作用模式与组织特异性主动摄取过程相结合 (uptake-1) 增强对侵袭性神经内分泌肿瘤（包括高危神经母细胞瘤）的药物输送 (NB) – 最致命的颅外儿童实体瘤，目前缺乏有效的治疗方案。 去甲肾上腺素转运蛋白 (NET) 驱动去甲肾上腺素及其功能类似物的积累 由交感肾上腺前体细胞发展而来的大多数实体瘤表达。然而，肿瘤 针对 NET 的放射治疗显示出有限的效率，同时由于以下原因造成严重的副作用： 显着的脱靶分布和对健康组织的广泛损害。以双选为中心 将摄取 1 过程与复制依赖模式相结合的实验药物递送策略 药物作用限制药理学作用于表达 NET 的增殖性肿瘤细胞，这 该项目旨在评估和优化旨在有效对抗 对现有治疗没有反应的难治性疾病，同时最大限度地减少对健康器官的毒性和 组织。在我们的概念验证实验中，将 NET 亲和力与 有效且选择性的拓扑异构酶 I 抑制剂的独特分子靶向被证明 对于实现持续的瘤内药物存在和显着延长生存期至关重要 侵袭性神经母细胞瘤的临床相关模型。根据这些结果，我们假设 使用 NET 靶向前药的双重选择性药物治疗可以提供选择性、安全和 治疗不同形式的高危疾病的有效方法。我们还假设效力和 通过与临床证明的小分子相结合，该方法的选择性将得到增强 调节 NET 组织特异性表达的药物。这些假设将通过追求 以下具体目标：目标 1 研究将侧重于聚合物载体连接的比较评估 前药构建体对原代 NB 细胞的细胞摄取和生长抑制作用 具有不同表型的细胞系，作为其分子设计和增强作用的函数 NET表达增强剂；目标 2 和目标 3 研究将比较评估 一系列三方前药的生物分布曲线和治疗效果，目的是 确定并优化关键构建变量，以确定药理调节的可行性 NET 表达以改善药物输送和治疗结果，并检查肿瘤的作用 侵袭性 NB 临床相关模型的表型和疾病状态。拟议的研究 专注于具有双重药理选择性的 NET 靶向前药具有重要意义 为治疗侵袭性 NB 和其他难治性癌症的新策略的开发提供信息。

Abstract This project focuses on the design and evaluation of prodrugs with dual pharmacological selectivity, combining molecularly targeted mode of action with a tissue-specific, active uptake process (uptake-1) to enhance drug delivery to aggressive neuroendrocrine neoplasms, including high-risk neuroblastoma (NB) – the deadliest extracranial pediatric solid tumor currently lacking effective treatment options. Norepinephrine transporter (NET) driving accumulation of norepinephrine and its functional analogs is expressed by most solid tumors developing from sympathoadrenal precursor cells. However, tumor radiotherapy targeted to NET has shown limited efficiency, while causing serious adverse effects due to significant off-target distribution and extensive damage to healthy tissues. Centered on a dual-selective experimental drug delivery strategy integrating the uptake-1 process with a replication-dependent mode of drug action to confine the pharmacological effect to proliferative tumor cells expressing NET, this project aims to evaluate and optimize a pharmacotherapeutic approach designed to effectively combat refractory disease not responding to existing treatments, while minimizing toxicity to healthy organs and tissues. In our proof-of-concept experiments, a tripartite prodrug design integrating NET affinity with unique molecular targeting of a potent and selective topoisomerase I inhibitor was shown to be essential for achieving sustained intratumoral drug presence and markedly extended survival in clinically relevant models of aggressive neuroblastoma. Guided by these results, we hypothesize that dual-selective pharmacotherapy using NET-targeted prodrugs can provide a selective, safe and efficient way of treating different forms of high-risk disease. We also hypothesize that potency and selectivity of this approach will be enhanced by combining it with clinically proven small-molecule agents modulating tissue-specific expression of NET. These hypotheses will be tested by pursuing the following specific aims: Aim 1 studies will focus on comparative evaluation of polymeric carrier-linked prodrug constructs with regard to their cell uptake and growth inhibitory effects on primary NB cells and cell lines with different phenotypes, as a function of their molecular design and the potentiating action of the NET expression enhancing agents; Aim 2 and Aim 3 studies will comparatively evaluate the biodistribution profiles and therapeutic effectiveness of a series of tripartite prodrugs, with the goal to identify and optimize key construction variables, to establish feasibility of pharmacologically modulating NET expression for improving drug delivery and treatment outcomes, and to examine the roles of tumor phenotype and disease status in clinically relevant models of aggressive NB. The proposed research focusing on NET-targeted prodrugs equipped with dual pharmacological selectivity is significant by informing the development of a new strategy for treating aggressive NB and other refractory cancers.