重组人血管内皮抑素腺病毒对人癌裸小鼠移植瘤的抑制作用

Inhibition of tumor growth in xenograft nude mice model by recombinant adenovirus-mediated human endostatin gene therapy

目的 观察重组人血管内皮抑素腺病毒 (Ad/hEndo)在体内、体外的表达效率 ,以及对裸鼠移植瘤肿瘤血管生成的影响。方法 携带人血管内皮抑素基因的新型重组腺病毒 (Ad/hEndo)及携带β 半乳糖苷酶基因 (LacZ基因 )的重组腺病毒 (Ad/LacZ)为自行构建。Ad/hEndo组 (7只 )瘤内注射 1× 10 9空斑形成单位 (pfu)的Ad/hEndo 10 0 μl,Ad/LacZ注射组 (6只 )瘤内注射 1× 10 9pfu的Ad/LacZ注射 10 0 μl,DMEM液注射组 (5只 )瘤内注射DMEM液 10 0 μl,共注射 5次。人鼻咽癌 (CNE 2 )和人脐静脉内皮细胞 (ECV30 4细胞 )被Ad/hEndo感染后 ,Western印迹和免疫酶联吸附法 (ELISA)检测人血管内皮抑素蛋白的表达。CNE 2细胞株移植到裸鼠背脊部后 ,检测Ad/hEndo对鼻咽癌裸鼠移植瘤生长的抑制作用 ,微血管密度计数 (microvesseldensity ,MVD)分析Ad/hEndo对肿瘤血管生成的影响。结果 Western印迹和ELISA法检测到人血管内皮抑素基因在CNE 2和ECV30 4细胞高效表达。当感染复数 (MOI)为 2 0pfu/细胞时 ,感染 72h后细胞培养上清中人血管内皮抑素蛋白浓度达 5 88 34ng/ml。Ad/hEndo可明显抑制鼻咽癌CNE 2裸鼠移植瘤生长 ,抑瘤率为 4 6 4 3% (Ad/hEndo治疗组对腺病毒携带基因LacZ注射组 ,t=2 2 2 6 ,P <0 0 5 )和 4 9 70 % (

Objective To investigate the expression efficiency of adenovirus-mediated human endostatin gene (Ad/hEndo) in vitro and in vivo, and to observe its inhibition of tumor growth in xenografted nude mice model. Methods The expression efficiency of endostatin gene was examined during the infection of Ad/hEndo in nasopharyngeal carcinoma (NPC) CNE-2 cell and human umbilical vein endothelial cells (ECV304) by Western blot and ELISA. The effect on inhibition of growth of NPC CNE-2 xenografted tumors in Balb/c nude mice was observed after administration with Ad/hEndo. The serum endostatin levels were measured by ELISA,and intratumoral microvessel density (MVD) was analyzed. Results Western blot and ELISA analysis demonstrated high level of endostatin expression in CNE2 and ECV304 cells infected with Ad/hEndo. The highest concentration of endostatin in supernatant reached 588.34 ng/ml after 72 h of Ad/hEndo infection at a MOI of 20. Ad/hEndo significantly inhibited growth of xenografted CNE-2 (nasopharyngeal carcinoma) tumors with inhibition rate of 46.43% (Ad/hEndo group versus Ad/LacZ group, t=2.226, P<0.05) and 49.70% (Ad/hEndo group versus DMEM group, t=2.254,P<0.05), respectively. In the study group, serum levels of endostatin in treated group were much higher than that of control groups for 3- and 7- day term. The intratumoral MVD also decreased significantly in the treated tumors (9.95 ± 2.20 versus 18.54±1.80, t=7.158, P<00.5). Conclusion Adenovirus-mediated human endostatin gene had obtained high level of expression in vitro and in vivo, and significantly inhibited the angiogenesis and growth of CNE-2 xenografted tumors in nude mice.