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

摘要 该项目的重点是设计和评价具有双重药理选择性的前药， 将分子靶向作用模式与组织特异性主动摄取过程相结合(摄取-1) 加强对侵袭性神经内分泌肿瘤的药物输送，包括高危神经母细胞瘤 (NB)-目前缺乏有效治疗选择的最致命的儿童颅外实体肿瘤。 去甲肾上腺素转运体(NET)驱动去甲肾上腺素及其功能类似物的蓄积 大多数由交感神经肾上腺前体细胞发展而来的实体瘤表达。然而，肿瘤 针对Net的放射治疗显示出有限的疗效，同时由于以下原因造成严重的不良反应 严重偏离目标的分布和对健康组织的广泛损害。以双重选择为中心 将摄取-1过程与复制依赖模式相结合的实验性给药策略 药物作用仅限于表达Net的增殖性肿瘤细胞，这 该项目旨在评估和优化一种旨在有效对抗 顽固性疾病对现有治疗无效，同时将对健康器官的毒性降至最低 纸巾。在我们的概念验证实验中，将净亲和力和 一种有效和选择性的拓扑异构酶I抑制剂的独特分子靶向被证明是 对于实现持续的肿瘤内药物存在和显著延长的生存是必不可少的 侵袭性神经母细胞瘤的临床相关模型。在这些结果的指导下，我们假设 使用网络靶向前体药物的双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 这种方法的选择性将通过将其与临床证明的小分子相结合来增强 调节Net的组织特异性表达的试剂。这些假说将通过追求 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价 前药构造物对原代NB细胞的摄取和生长抑制作用 不同表型的细胞系，作为其分子设计和增强作用的函数 净表达增强剂；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和治疗效果，目的是 识别和优化关键结构变量，建立药物调控的可行性 NET表达改善药物传递和治疗结果，并检查肿瘤的作用 侵袭性神经营养不良临床相关模型的表型和疾病状态。拟议的研究 关注具有双重药理选择性的净靶向前药具有重要意义 为开发治疗侵袭性NB和其他难治性癌症的新策略提供信息。

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.