血管内皮抑素基因制剂对肝癌的实验研究

Effects of endostatin transfected bifidobacterium on experimental liver cancer.

目的 研究血管内皮抑素转基因双歧杆菌口服冻干粉剂 (endostatintransfectedbifido bacteriumoralpowderpreparation ,ETB 2 )对小鼠HAC肝癌细胞皮下移植模型的抑瘤作用 ,探讨其抑瘤机制。方法 小鼠HAC肝癌细胞株皮下接种模型 ,实验组分接种细胞后 2 4h(ETB 2A)和 1周 (ETB 2B)两个时段给药。动物处死后剥离肿瘤 ,称重并计算抑瘤率。苏木精 伊红和EnvisionSystem免疫组化方法 ,分别计数微血管密度 (MVD)、增殖细胞核抗原 (PCNA)指数和血管内皮生长因子 (VEGF)阳性率 ,分析它们同ETB 2抑瘤效应之间的关系。结果 实验组抑瘤率ETB 2A为 5 1.0 6 % ,ETB 2B为39 .10 %。实验组MVD ,ETB 2A为 8.10± 2 .0 3 ,ETB 2B为 12 .0 2± 1.5 4,显著低于对照组 (P <0 .0 5 )。VEGF阳性率ETB 2A为 4.2 0± 1.5 1,ETB 2B为 4.5 0± 2 .82 ,同对照组相比差异有显著性 (P <0 .0 5 )。PCNA指数实验组有降低趋势 ,但差异无显著性。结论 ETB 2可显著抑制小鼠肝癌的生长和发展 ,并有一定的时效关系 ,其可能的抑瘤机制为抑制肿瘤血管增殖 ,使肿瘤坏死增加 。

Objective To investigate the effects of endostatin transfected bifidobacterium oral preparation (ETB 2) on mice liver cancer and its' mechanism. Methods The mice liver carcinoma cell line HAC was implanted subcutaneously in Kunming mice. Mice were randomly divided into five groups including negative control group (infused with distrolled water), positive control group (CTX infused intra peritoneally), bifidobacterium group, ETB 2A group (ETB 2A was given 24 h after cells implantation) and ETB 2B group (ETB 2 was given 1 week after cells implantation). Each group had 10 mice, and all drugs were given by gavage. Seventeen days later mice were killed and tumors were weighted and calculated the restrained percen tage of tumor. In addition, using HE and immunohistochemical methods, the microvessel density (MVD)、 the positive rate of vascular endothelial growth factor (VEGF) and the proliferating cell nuclear antigen (PCNA) index were studied. Results Compared with negative control group with the MVD of 16.80±5.22, the PCNA index of 77.10±6.31, and the VEGF positive rate (%) of 11.53 ±4.25, in ETB 2A group the restrained percentage of tumor was 51.06%, the MVD was 8.10± 2.03 ( P <0.05), the PCNA index was 50.56±8.37 ( P >0.05), the positive rate of VEGF (%) was 4.20±1.51 ( P <0.05); in ETB 2B group the results were 39.10%, 12.02±1.54( P <0.05), 58.86±2.59( P >0.05), 4.50±2.82( P <0.05), respectively. In positive control (CTX) group those were 83.79%, 11.49 ±2.82( P <0.05), 58.19±4.12( P >0.05), 5.40±3.88( P <0.05); in bifidobacterium group those were 14.90%, 13.75±3.36( P > 0.05), 65.61±13.00( P >0.05), 10.88±6.24( P >0.05), respectively. Conclusions Above data indicated that the ETB 2 could significantly restrain the development of mice liver cancer, and the effects depended on the time of administration. The mechanism may be due to its' effects of antiangiogensis, increasing necrosis and decreasing proliferation. Bifidobacterium has no significant antitumor function but could improve the immune function. Bifidobacterium may cooperate with endostatin in antitumor process.