GD2靶向温敏胶束联合治疗神经母细胞瘤及抑制耐药的机制研究

Neuroblastoma is a common extracranial primary malignant tumor among pedia. As the primary treatment, chemotherapy is poor specificity and easy to trigger neuroblastoma multidrug resistance. Therefore, how to find a method to enhance chemotherapy specificity and suppress multidrug resistance of tumor cells becomes an urgent problem in clinic. The researches indicated that the high expression of GD2 was a specific marker in neuroblastoma cells, as well as the overexpression of P-gp would lead to tumor multidrug resistance. Previous research showed that thermosensitive polymeric micelle could significantly promote intracellular uptake and enhance antitumor effect. Therefore, the project constructed GD2-targeted thermosensitive micelle (GDIM) by using anti-GD2 antibody, P-gp inhibitor TPGS, and thermosensitive polymer PID117-b-PLA71. Previous study found that GDIM had proper size and excellent thermosensitive property. With the chemotherapy drug and photothermal therapy drug, GDIM preliminary showed significant antitumor effect by the chemo- and photothermal combined therapy. On this basis, this project optimizes the composition and physicochemical characteristics of GDIM, and studies synergistic effect between the passive target and active target in the neuroblastoma treatment. Besides, the antitumor mechanism of GDIM in vitro and in vivo will be investigaed, elucidating the mechanism of GDIM suppressing tumor multidrug resistance. It is expected that this project could provide new treatment theoretical basis and therapeutic strategies in targeted neuroblastoma treatment.

神经母细胞瘤是儿童常见的颅外原发性恶性肿瘤。化疗作为主要治疗手段，特异性差且易产生耐药。因此，寻找增强化疗特异性并抑制耐药的方法是临床上亟待解决的问题。研究表明，神经母细胞瘤特异性高表达GD2，且耐药的发生与P-gp的高表达密切相关。前期研究发现，温敏高分子胶束能显著促进细胞内吞、增强抗肿瘤作用。为此，本项目结合抗GD2抗体、P-gp抑制剂TPGS，温敏高分子PID117-b-PLA71，构建出GD2靶向温敏胶束(GDIM)。前期研究发现：GDIM具有合适的粒径、良好的温敏性能，负载化疗药物和光热剂后，初步显示出较强的联合(化疗和光热治疗)抗肿瘤作用。在此基础上，本项目拟进一步优化GDIM的组成和理化特性，探讨GDIM协同靶向(抗体主动靶向和温敏被动靶向)的作用特点，研究GDIM体内外抗肿瘤的作用机制，阐明GDIM抑制耐药的作用机制。为神经母细胞瘤的靶向治疗提供新的理论基础和治疗策略。

神经母细胞瘤是儿童常见的颅外原发性恶性肿瘤。化疗作为主要治疗手段，特异性差且毒副作用大。因此，本项目从靶向治疗，显像治疗一体化和免疫治疗三个方面尝试为神经母细胞瘤的治疗提供新的策略。本项目研究表明：1、结合抗GD2抗体、P-gp抑制剂TPGS，温敏高分子PID117-b-PLA71，构建出GD2靶向温敏胶束。结果表明：通过调控合成方法，制备得到的靶向温敏胶束能显著促进肿瘤细胞内吞化疗药物、增强化疗药物的抗肿瘤效果。2、将单壁碳纳米管进行聚多巴胺修饰后，并结合锰离子和放射性碘，制备出多功能纳米载体材料，并在多模态成像基础上，实现光热治疗和放疗联合治疗肿瘤。结果表明：制备出的多功能纳米载体材料，具有磁共振、核素和热成像三模态成像功能，在体内外联合光热治疗和放疗有效杀伤肿瘤。3、以模式抗原OVA，锰离子和NOD1激动剂分子成功制备出纳米疫苗，并在此纳米疫苗的基础上，联合免疫检查点抑制剂anti-PD-1抗体实现联合免疫治疗肿瘤。结果表明：制备的纳米疫苗可以有效促进抗原进入细胞，促进树突状细胞成熟和交叉呈递，并有效促进多种细胞因子分泌。体内结果进一步证明，该纳米疫苗可以有效触发体内免疫反应，增强体内抗肿瘤效应。联合anti-PD-1抗体后，可以进一步放大免疫治疗的抗肿瘤效果。至此本项目从多个方面为神经母细胞瘤的治疗提供新的理论基础和治疗策略。