利用嵌合蛋白RBDV-IgG1 Fc來運送微脂體/DNA複合體至專一性部位

Abstract

血管新生成對腫瘤生長和轉移扮演了非常重要的角色，因此抑制血管新生成已成為一個治療癌症的方式。在先前實驗中，本實驗室建構一嵌合蛋白RBDV-IgG1 Fc (Receptor binding domain of human VEGF-Immunoglobulin): 是以人類血管內皮生長因子A(VEGF-A)中第8至109胺基酸和人類免疫球蛋白G1之Fc片段建構而成。 RBDV-IgG1 Fc嵌合蛋白已被證實在C57/BL6小鼠中能抑制腫瘤生長，因此本研究則是以RBDV-IgG1 Fc嵌合蛋白當作標靶分子來使用，利用新型帶正電微脂體(Lipo-PEI-PEG-complex, LPPC)來同時吸附RBDV-IgG1 Fc嵌合蛋白以及會表現RBDV-IgG1 Fc嵌合蛋白的RBDV-IgG1 Fc質體進行癌症之基因治療。於細胞實驗當中，此質體表現的RBDV-IgG1 Fc嵌合蛋白可藉由誘發抗體依賴型毒殺反應以及補體調控毒殺機制來毒殺細胞，並於活體實驗中證實RBDV-IgG1 Fc/LPPC複合體可專一性標靶至B16/F10腫瘤，並且吸附的RBDV-IgG1 Fc質體可被穩定表現RBDV-IgG1 Fc嵌合蛋白來抑制腫瘤生長。以上結果顯示，LPPC結合RBDV-IgG1 Fc質體以及RBDV-IgG1 Fc嵌合蛋白可能是一個有潛力的工具來進行基因治療。

Angiogenesis is critical for tumor growth and metastasis, and several angiogenesis inhibitors have been developed for the treatment of cancer. Previously, a recombinant fusion protein (RBDV-IgG1 Fc) was constructed which was composed of a receptor binding domain of human VEGF-A (residues 8–109) and a Fc region of human IgG1 immunoglobulin. It has been shown to prevent tumor growth in C57/BL6 mouse model. In this study, we have used a gene transfer method based on a novel cationic liposome (Lipo-PEI-PEG-complex, LPPC) to adsorb RBDV-IgG1 Fc targeting protein molecular, and plasmid DNA containing transgene to express RBDV-IgG1 Fc, simultaneously. This expressing RBDV-IgG1 Fc protein could induce antibody dependent cellular cytotoxicity (ADCC) and complement-mediatted cytotoxicity (CDC) in vitro. In vivo the RBDV IgG1 Fc /LPPC complexes could specifically target to B16/F10 tumors, and RBDV IgG1 Fc plasmid could significantly express to inhibition tumor growth. Therefore, LPPC complex combined with RBDV-IgG1 Fc plasmid and RBDV-IgG1 Fc protein was a potential tool for gene delivery.