新型C-PC/CMC-CD55sp纳米微球的构建及靶向性抗肿瘤效应研究

Our previous experimental results revealed that a novel natural marine extract C-phycocyain (C-PC) could inhibit CD55 expression on the surface of HeLa cells and then induce the apoptosis of tumor cells,but the detailed mechanism was not clear. The poor targeting of C-PC limits its application in medical field.This study innovatively combines the advantage of the targeting property of CD55-specific ligand peptide (CD55sp), biocompatibility of carboxymethyl chitosan (CMC), nontoxity and high efficiency of C-PC, and penetrability of nanoparitcles, to fulfill the research on a comprehensive cancer-targeting therapy. This project aims to make CD55sp-CMC/C-PC nanoparticles by embedding C-PC in CD55sp-conjugated CMC which acts as a drug target carrier. C-PC will be directionally transferred into tumor cells under the guidance of the cancer-targeting CD55sp that has been conjugated with CMC. The efficient targeted antitumor activities of the composite nanoparticles on three kinds of cancer cells of genital system (cervical cancer HeLa cells, breast cancer MCF-7 cells, and prostatic cancer PC-3 cells) will be evaluated through in vitro and in vivo experiments. The molecular mechanism of the nanoparticles inducing transmembrane apoptotic signal transduction will be discussed. It provides a new idea for the research and development of new comprehensive marine drugs and opens up a new way for tumor-targeting therapy.

本课题组前期研究发现新型海洋提取物-藻蓝蛋白(C-PC)具有抑制HeLa细胞表面CD55分子表达、从而促进肿瘤细胞凋亡的功效，但其详细机制尚待探讨。由于藻蓝蛋白的靶向性差，其应用受到限制。本研究创新性地利用藻蓝蛋白无毒高效性、CD55配体肽（CD55sp）的靶向性、羧甲基壳聚糖（CMC）的生物相容性，构建三位一体的新型载药纳米微球（CD55sp-CMC/C-PC）。本课题是以CD55sp修饰的CMC作为肿瘤靶向药物载体，包埋C-PC合成新型纳米微球，利用CMC上连接的CD55sp的导向作用，将C-PC定向输送到肿瘤细胞内。然后通过体内外实验评价该纳米微球对生殖系统肿瘤的高效靶向抗肿瘤效应（宫颈癌HeLa、乳腺癌MCF-7、前列腺癌PC-3细胞），进一步揭示其促进肿瘤细胞跨膜凋亡信号转导的分子机制，为新型海洋药物的研发提供了新思路、为肿瘤的综合靶向治疗开辟了新途径。

本课题组前期预实验发现新型海洋药物藻蓝蛋白(C-PC)抗肿瘤效果显著且安全无毒，但其靶向性、稳定性较差，限制了它在医药领域的应用。另外在多种实体瘤中发现了CD55和CD59的高表达。本课题通过噬菌体展示技术筛选CD55和CD59特异配体肽（CD55sp，CD59sp），并以CD55和CD59特异配体肽修饰的羟甲基壳聚糖（CMC）作为肿瘤靶向药物载体，包埋藻蓝蛋白合成新型纳米微球（CD55sp-CMC/C-PC和CD59sp-CMC/C-PC），利用羟甲基壳聚糖分子上连接的CD55特异性配体肽的导向作用，将藻蓝蛋白定向输送到肿瘤细胞内。通过体内外实验评价该纳米微球对三种宫颈癌细胞（宫颈癌HeLa细胞、SiHa细胞、Caski细胞）的靶向性及抗肿瘤效应，并对作用机制进行了探讨。本研究创新性地利用CD55配体肽的靶向性、羟甲基壳聚糖的可降解性、藻蓝蛋白低毒高效性、纳米微球的穿透性，构建四为一体的新型靶向药物。本课题不仅为新型综合性海洋药物的研发提供了新思路，并为肿瘤的综合靶向治疗开辟了新途径，具有重要的理论意义和临床应用价值。