血管抑素下调人舌鳞癌细胞血管内皮生长因子的表达

Angiostatin down-regulates vascular endothelial growth factor expression in human tongue squamous cell carcinoma cells

目的探讨血管抑素(angiostatin,AS)对人舌鳞癌细胞血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的影响。方法将Tca8113人舌鳞癌细胞移植到18只裸鼠皮下,用随机数字表法将裸鼠分成3组(每组6只)。PBS组:注射PBS;AS(250ng)组:注射250ng纯化AS;AS(30μg)组:注射30μg纯化AS,腹腔注射,2次/d,同时测量肿瘤的大小,2次/周。21d后处死小鼠,将取出的每个肿瘤2等分,一半用免疫组织化学检测VEGF及其两个受体(VEGFR1、VEGFR2)和CD34,用TUNEL法检测肿瘤细胞的凋亡;另一半用半定量RT-PCR检测VEGF、VEGFR1和VEG-FR2的mRNA表达。结果AS(250ng)组和AS(30μg)组中,细胞凋亡指数(AI)明显增加(P<0.05);而肿瘤体积、微血管密度(MVD,用CD34抗体标记并用来评价肿瘤血管生成)及VEGF、VEGFR1和VEGFR2在蛋白质和mRNA的水平表达,都有明显降低(P<0.05),且AS(30μg)组更为显著。结论AS下调人舌鳞癌细胞VEGF的表达且呈剂量依赖性。

Objective To evaluate the effects of angiostatin on vascular endothelial growth factor expression in human tongue squamous cell carcinoma cells. Methods Subcutaneous xenografls of human tongue squamous cell carcinoma （TeaS113） cell line in BALB/e nude mice were employed and eighteen mice were randomly divided into three groups （6 mice each） ： the PBS group injected with PBS, the AS group injected with 250 ng purified angiostatin, and the AS group injected with 30 μg purified angiostatin. Reagents were injected intraperitoneally twice daily and tumor volume was calculated twice weekly for 21 d, then animals were sacrificed and each tumor specimen was divided into two parts after surgical resection. The first part was submitted to both immunocytochemistry for VEGF, VEGFR1, VEGFR2 and CD34, and TUNEL apoptosis assay. The second part was prepared for semi-quantitative RT-PCR analysis of VEGF, VEGFR1 and VEGFR2 mRNA abundance. Results There was an increase of apoptotic index （AI） （P 〈 0.05） in the AS （250 ng） group and in the AS （30 μg） group and there was a decrease of protein and mRNA expression levels of VEGF, VEGFR1 and VEGFR2, tumor volume and MVD （tumor angiogenesis was estimated by using CD34 antibody to determine mierovessel density） （P 〈0. 05）. These changes were more obvious in the the AS （30 μg） group than in the AS （250 ng） group（P 〈 0.05）. Conclusion Angiostatin down-regulates vascular endothelial growth factor expression in human tongue squamous cell carcinoma cells in a dose-dependent manner.