活体观察贝伐单抗对人骨肉瘤裸鼠移植瘤模型的作用

目的 探讨贝伐单抗（Avastin）对人骨肉瘤143-B裸鼠移植瘤模型生长和血管生成的影响。方法 将成功建立的红色荧光蛋白标记的人骨肉瘤143-B裸鼠原位种植模型随机分为3组：对照组（生理盐水）、低剂量贝伐单抗组（Avastin-L，2.0mg/kg）和高剂量贝伐单抗组（Avastin-H，5.0mg/kg），每组7只。贝伐单抗每次腹腔注射0.2ml，1周2次，持续3周；对照组给予等体积生理盐水。每隔3天记录各组体质量，每隔7天用荧光影像系统测量原位肿瘤大小并计算抑瘤率；采用免疫组化En Vision法检测各组肿瘤组织中的CD34表达并计算微血管密度（MVD）；酶联免疫吸附法检测各组血浆和肿瘤组织的血管内皮生长因子（VEGF）的水平。结果 3组实验裸鼠体质量及肺部转移率的差异无统计学意义（P＞0.05）；与对照组相比，Avastin-L组和Avastin-H组的肿瘤体积减小，MVD、血浆及肿瘤组织的VEGF水平降低，差异均有统计学意义（P＜0.05）；Avastin-H组对上述指标的改善程度优于Avastin-L组（P＜0.05）。结论 Avastin对人骨肉瘤143-B肿瘤生长有抑制作用，同时可降低血管生成及VEGF水平，但对肺部转移无明显抑制作用。

Effect of bevacizumab in the RFP-tagged osteosarcoma nude mice model of human osteosarcoma in vivo

Objective To explore the influence of bevacizumab （ Avastin） on the growth and angiogenesis of RFP-tagged os-teosarcoma orthotopic nude mice model of human osteosarcoma. Methods Twenty-one nude mice inoculated with human osteosarcoma cell line 143-B-RFP were randomly divided into three groups：control group, low dose Avastin group （ Avastin-L） and high dose Avas-tin group （ Avastin-H） . Avastin-L group and Avastin-H group received continuous 0. 2ml injection of 2. 0mg/kg or 5. 0mg/kg Avastin twice a week for 3 weeks, while control group was given an equal volume of saline. The body weight was recorded every 3 days. The in situ tumor size was measured to calculate the volume and the tumor inhibition rate every 7 days by fluorescence imaging system. Immu-nohistochemical En Vision method was used to detect the expression of CD34 in tumor tissue to evaluate the microvessel density （ MVD） . The vascular endothelial growth factor （ VEGF） levels of plasma and tumor tissue were measured by ELISA method. Results No significant difference was observed on body weight and lung metastasis rate among 3 groups （ P〉0. 05） . Compared with control group, there were higher tumor inhibition rate, and lower tumor volume, MVD and VEGF levels of plasma and tumor tissue in both Avastin-L group and Avastin-H group （P〈0. 05）.The improvement effect of the above indexes were stronger in Avastin-H group versus Avastin-L group （ P〈0. 05） . Conclusion Avastin can inhibit the growth and angiogenesis of human osteosarcoma, and reduce the VEGF level without influences on lung metastasis.