基于线粒体Kv1.3通道的抗肿瘤多肽药物传递系统研究

Pro-apoptotic protein Bax induces apoptosis by directly binding to and inhibiting mitochondrial Kv1.3 channels (mtKv1.3). Thus, the mtKv1.3 channels have been considered as a promising therapeutic target to overcome drug resistance and tumor recurrence. However, it remains challenging to develop safe and efficient mtKv1.3 channel-targeted drugs. Based on the potent and highly-selective Kv1.3 channel-inhibiting scorpion toxin peptides explored in our preliminary work, we propose to develop a novel PEG-modified long circulating liposomal drug delivery system by developing the optimal liposome formation to encapsulate the bioactive peptide. Furthermore, the liposomal system is modified by sgc8, the specific-targeting aptamer of the T-cell acute lymphoblastic leukemia, which can specifically deliver the Kv1.3 channel-inhibiting peptides with sustained released effects in the targeted-tumor cells，and induce considerable antitumor effects. The research of its antitumor effect and mechanism in BALB/c nude mouse leukemia xenograft model, together with the exploration of pharmacokinetic characteristics, distribution profiling, and safety evaluation in vivo will provide new insights to develop the potential clinical applications of mtKv1.3 channel-targeted drugs, and also provide effective theoretical guidance and practical basis for developing novel cancer therapy.

促凋亡蛋白Bax阻断线粒体Kv1.3通道（mitochondrial Kv1.3 channels, mtKv1.3）诱导肿瘤细胞凋亡，mtKv1.3成为极有希望克服临床肿瘤耐药复发的新治疗靶点。但目前尚无安全高效的mtKv1.3靶向药物研制成功。基于前期自主研制的高效、专一阻断Kv1.3的蝎毒多肽，拟设计PEG修饰的长循环脂质体最优处方包裹该活性多肽，并以特异性靶向急性T淋巴细胞白血病肿瘤细胞适配体sgc8修饰该载药系统，通过缓释作用将多肽靶向性地稳定投递到肿瘤细胞内，实现可观的抗肿瘤效应；建立BALB/c裸鼠白血病移植瘤模型研究其体内靶向性、抗肿瘤效应及作用机制；并研究其在BALB/c裸鼠体内的药代动力学参数、阐明其代谢及分布特点，并评价其体内安全性。本课题从崭新角度探索靶向mtKv1.3通道多肽药物传递系统的潜在临床应用价值，为发展抗肿瘤的新型治疗方法提供有效的理论基础和实践依据。

促凋亡蛋白Bax 被发现通过阻断线粒体 Kv1.3 离子通道（mitochondrial Kv1.3 .channels, mtKv1.3）启动线粒体途径细胞凋亡，mtKv1.3 由此成为极有希望克服临床肿瘤耐药复发的新治疗靶点之一。本课题使用适配体sgc8修饰的PEG长循环脂质体包载靶向Kv1.3多肽DD3233s,成功构建了靶向mtKv1.3的药物传递系统，并对该载药系统进行了各项表征检测。结果证实该系统体系稳定，粒径为156.067 ± 0.896 nm、PDI为0.045 ± 0.016，Zeta电位为-19.333± 0.351 mV、载药浓度94.5 μg/mL，电镜检测等表征检测结果均符合肿瘤治疗用纳米材料要求。该体系在体外能有效抑制急性T淋巴细胞白血病细胞并显著性诱导靶细胞凋亡，但对慢性淋巴细胞白血病细胞无显著性抑制作用。并且在体内能有效抑制荷瘤小鼠的肿瘤生长，抑制效率为32.680%（p-value < 0.05）。本项目对该药物系统在小鼠体内的分布、代谢特点及安全性进行了评价，载荧光药物脂质体处理的荷瘤鼠在肿瘤部位显示较强荧光，提示该脂质体载药系统在肿瘤处蓄积，但主要在荷瘤鼠肝脏和脾脏内蓄积。安全性实验证实该系统未引起动物明显异常反应，解剖后实验动物主要脏器无肉眼可见的病变，H&E染色结果证实各脏器未发现病变，未发现免疫浸润现象，提示该药物传递系统具有一定安全性。该系统可未将来临床应用提供可靠的理论基础和实践依据。本课题首次建立以线粒体Kv1.3 离子通道为肿瘤治疗靶点的靶向性多肽药物传递系并探索其作用机制、体内和体外抗肿瘤效应，为发展不依赖于Bax 表达的新型肿瘤治疗手段提供准确有效的理论指导和临床实践依据。