pcDNA3/AFP/TK/Angio融合基因靶向性治疗人原发性肝癌的实验研究

目的研究pcDNA3/AFP/TK/Angio融合基因对人肝癌细胞系SMMC-7721裸鼠移植瘤模型的靶向性治疗作用。方法建立人原发性肝癌裸鼠皮下移植瘤模型,将荷瘤裸鼠随机分成肿瘤对照组、空质粒组、丙氧鸟苷（GCV）组、pcDNA3/TK/Angio组及pcDNA3/AFP/TK/Angio组5组。于瘤体内分别直接注射不同的质粒,同时于裸鼠腹腔内注射GCV,观察不同时段皮下肿瘤的生长情况并做病理学检查,免疫组化法检测肿瘤微血管密度（MVD）以及血管内皮细胞生长因子（VEGF）的表达量,原位末端标记（TUNEL）法检测细胞原位凋亡。放免法检测裸鼠血清甲胎蛋白（AFP）的变化,透射电镜观察肿瘤细胞超微结构的变化。结果裸鼠皮下成瘤率100%;pcDNA3/TK/Angio组及pcDNA3/AFP/TK/Angio组的肿瘤体积、血清AFP含量、肿瘤MVD和VEGF表达强度均明显低于对照组、空质粒组和GCV组（P〈0.05）,细胞凋亡指数都明显高于后3组（P〈0.05）,可见较多的凋亡细胞。而pcDNA3/AFP/TK/Angio组的肿瘤体积、AFP、MVD及VEGF表达强度又明显低于pcDNA3/TK/An-gio组（P〈0.05）,凋亡指数高于后者（P〈0.05）。结论pcDNA3/AFP/TK/Angio融合基因系统可显著抑制肿瘤的生长,有望成为治疗原发性肝癌的新型生物制剂之一。

Experimental Study of pcDNA3 /AFP /TK /Angio Fusion Gene Targeting Therapy for Human Primary Liver Cancer

Objective To study the effects of pcDNA3/AFP/TK/Angio fusion gene targeting therapy for human primary liver cancer in nude mice implanted with SMMC-7721. Methods Human liver cancer cell line SMMC-7721 was implanted subcutaneously in nude mice to establish experiment model. Animals bearing liver cancer were randomly divided into five groups: control group, vector group, GCV (ganciclovir) group, pcDNA3/TK/Angio group; pcDNA3/AFP/TK/Angio group. Different plasmids were directly injected into tumors and GCV was intraperitoneally administrated simultaneously according to different groups. The growth of tumors was observed and the pathology was examined as well. Serum AFP level was measured by radioimmunology, the ultrastructural change of tumor cells was studied by using electron microscopy, the expressions of MVD and VEGF were respectively detected with immunohistochemistry and the cell apoptosis in situ was detected by TUNEL. Results The success rate to establish subcutaneous implanted liver cancer model in nude mice was 100%. The tumor volume, serum AFP level, VEGF and MVD expressions of pcDNA3/TK/Angio group and pcDNA3/AFP/TK/Angio group were lower than those in control group, vector group and GCV group (P<0.05) and more apoptosis cells could be observed. While the tumor volume, serum AFP level, VEGF and MVD expressions of pcDNA3/AFP/TK/Angio group was lower than those in pcDNA3/TK/Angio group (P<0.05); and apoptosis index was higher than that of the latter (P<0.05). Conclusion pcDNA3/AFP/TK/Angio fusion gene inhibits the growth of tumor remarkably and becomes a promising new biological agent to treat human primary liver cancer.