新型靶向纳米药物Angio-Ag-NRPMAb的制备及其抑制胶质瘤的机制研究

Glioma is the most common primary intracranial malignant tumor with high postoperative recurrent rate. It is hardly sensitive to radiotherapy and chemotherapy.So the prognosis of gliomas is very poor. Neuropilin-1 (NRP-1) is highly expressed in glioma cells, which can be used as a new target for glioma-targeted therapy. In our previous study, the human anti-NRP-1 b1/b2 monoclonal antibody (NRP-1 b1/b2 MAb) was developed and the inhibitory effect of the NRP-1 b1/b2 MAb on gliomas was confirmed. However, the NRP-1 b1/b2 MAb could not be easy to cross the blood-brain barrier. In addition, the preliminary study found that silver nanoparticles have good radiosensitizing effect on tumors. Therefore, we intend to use silver nanoparticles as an assistance for radiotherapy of gliomas. Firstly, we will make silver nanoparticles modified with Angiopep-2 peptide, which is capable of penetrating the blood-brain barrier and targeting gliomas. Then the modified silver nanoparticles will be chemically coupled with the NRP-1 b1/b2 MAb, which results in the development of a new nanoprobe named as Angio-Ag-NRPMAb probe. The in vivo biocompatibility and distribution, the ability to penetrate the blood-brain barrier and target gliomas, the in vitro / in vivo inhibitory effects on gliomas and their molecular mechanisms of the Angio-Ag-NRPMAb probe will be investigated. Our study will provide an experimental basis for the development of a new nanoprobe capable of penetrating the blood-brain barrier, radiosensitizing, and attaining the collaborative targeted therapy of gliomas.

脑胶质瘤是最常见的颅内原发恶性肿瘤，由于术后复发率高，对放化疗不敏感，故患者的预后极差。文献报道神经纤毛蛋白-1（Neuropilin-1，NRP-1）高表达于胶质瘤细胞，可作为胶质瘤靶向治疗的新靶标。我们前期研究构建了人源抗NRP-1 b1/b2单克隆抗体，证实对胶质瘤增殖、迁移、粘附有抑制效应，但该抗体不易穿透血脑屏障。因此我们拟采用可穿透血脑屏障且靶向脑胶质瘤的Angiopep-2肽修饰银纳米颗粒与抗NRP-1 b1/b2 单克隆抗体化学偶联，制备成Angio-Ag-NRPMAb探针。评价该探针的生物安全性，研究其体内分布规律、穿透血脑屏障的能力、体外/体内靶向抑制胶质瘤效应及相关分子机制，为探索高效靶向治疗脑胶质瘤的新型合成纳米探针提供实验及理论依据。

随着基因精准医疗的到来，基因靶向治疗的快速发展，为包括脑胶质瘤在内的各种难治性疾病提供了一种新的治疗策略。本项目在前期对NRP-1单克隆抗体的研究基础上，进一步探索了NRP-1基因通路在胶质瘤中的重要作用，摸清了其上下游的关键调控分子机制。研究结果发现NRP-1基因在下游是通过GIPC1-APPL1 / p130Cas-KRAS / ERK信号通路来调控胶质瘤的增殖、侵袭和凋亡表型；在上游主要是被miRNA-124-3p特异性靶向从而参与胶质瘤的发生发展，且是通过PI3K/Akt/NFκB 和 ERK/c-myc信号通路来调节胶质瘤的增殖、侵袭、迁移、凋亡以及肿瘤血管发生。另外纳米银主要通过促进细胞炎症氧化应激和介导细胞线粒体膜电位下降而诱导神经细胞的自噬凋亡。因此，本研究主要证实了miRNA-124-3p / NRP-1 / GIPC1通路轴在胶质瘤中的重要作用，可以被认为是未来胶质瘤基因靶向治疗过程中新的治疗靶点或联合治疗靶点。