肿瘤靶向性载体介导的IL-12 基因增强裸鼠抗骨肉瘤免疫

 目的 观察以转铁蛋白-多聚乙烯亚胺(Transferrin-polyethylenimine，Tf-PEI)为靶向性载体，体内转染小鼠白细胞介素12(murine interleukin-12，mIL-12)基因，治疗裸鼠骨肉瘤模型的疗效。方法 以Tf-PEI为载体，体外转染mIL-12基因入人骨肉瘤细胞，并以游离转铁蛋白竞争性拮抗Tf-PEI，观察基因表达情况。将Tf-PEI包裹mIL-12基因直接注入荷瘤裸鼠的肿瘤局部，检测此基因在肿瘤细胞中的表达情况和小鼠脾脏自然杀伤细胞(NK)活性。结果 Tf-PEI可以靶向性的将mIL-12基因导入人骨肉瘤细胞。在Tf-PEI／DNA治疗组小鼠的肿瘤局部，mIL-12蛋白水平明显升高，小鼠脾细胞NK活性增强。结论 Tf-PEI是一种高效率的肿瘤靶向性基因转染载体，它可以成功的将mIL-12基因导入裸鼠骨肉瘤模型，mIL-12基因治疗可提高机体的抗肿瘤免疫应答。

A Tumor-targeted Vector for Interleukin-12 Gene Therapy to Enhance the Anti-osteosarcoma Immunity in Nude Mouse

Objective To determine whether transferrin- polyethylenimine (Tf-PEI), a tumor-targeted DNA carrier, can be used to deliver the IL-12 gene into the nude mouse model of human osteosarcoma, and to observe the effect of gene therapy. Methods Using Tf-PEI as the vector, deliver murine interleukin-12 (mIL-12) gene into human osteosarcoma cells. Free transferrin was used to inhibit Tf-PEI, and the influence was observed. Tf-PEI-IL12 plasmid complexes were introduced into the nude mouse model of human osteosarcoma by direct intratumor gene injection. Lactic dehydrogenase (LDH) assay was used to evaluate the activity of natural killer (NK) cells. Results Tf-PEI can effectively and specifically deliver murine interleukin-12 gene into human osteosarcoma. We also demonstrated that treatment using Tf-PEI-IL-12 plasmid complexes resulted in significant IL-12 expression in the tumor. Greater activity of NK was also observed in the therapy group as compared with the controls. Conclusion Tf-PEI is a high efficiency and low cytotoxicity tumor-targeted vector. It can successfully introduce mIL-12 gene into nude mouse model of human osteosarcoma, and IL-12 gene therapy is able to induce the host antitumor immune response efficiently.