VEGF基因沉默抑制HCT116裸鼠移植瘤生长及血管生成的实验研究  

Gene silencing of VEGF inhibits growth and angiogenesis of human colon cancer HCT116 implanted in nude mice

作　　者：吕伟[1] 牛婧[1] 张超[1] 刘涛[1] 郝迎学[1] 刘伟[1] 余佩武[1] 

机构地区：[1]第三军医大学西南医院普通外科,重庆400038

出　　处：《第三军医大学学报》2007年第6期522-525,共4页Journal of Third Military Medical University

摘　　要：目的应用RNAi技术沉默血管内皮生长因子(vascular endothelial growthfactor,VEGF)基因,探讨其对人结肠癌细胞系HCT116裸鼠移植瘤生长及其血管生成的影响。方法将自行构建的以VEGF基因为靶向表达短发夹状RNA的重组质粒(pAVU6+27-VEGF-siRNA)转染到结肠癌HCT116细胞株中(C组),以空质粒(pAVU6+27)转染为阴性对照(B组),经G418筛选出阳性克隆细胞,未转染质粒的HCT116细胞株为空白对照(A组),建立裸小鼠皮下移植瘤模型。通过测量移植瘤的质量、体积观察移植瘤生长;免疫组化检测瘤组织中VEGF蛋白表达及组织内的微血管密度(mi-crovessel density,MVD)改变。结果C组肿瘤瘤块的体积(0.169±0.009)cm3和质量(0.192±0.022)g明显小于A、B组(P<0·05)。A、B组荷瘤组织中VEGF均表达强阳性,表达位于肿瘤细胞的细胞质及细胞膜上,呈棕黄色。C组荷瘤组织中VEGF呈弱阳性表达,组间差异显著(P<0·05)。C组荷瘤组织中MVD明显小于两对照组,组间差异显著(P<0·05)。VEGF表达与MVD呈显著正相关(r=0·810,P<0·01)。结论应用RNAi技术沉默VEGF基因能明显抑制人结肠癌细胞系HCT116裸小鼠移植瘤的生长,其机制与其抑制移植瘤中VEGF的表达和瘤组织内血管生成有关。Objective To observe the growth and angiogenesis of human colon cancer HCT116 implanted in nude mice after silencing VEGF gene expression with RNAi technique. Methods The sub-cloned recombi- nant plasmid shRNA （pAVU6 ＋ 27-VEGF-siRNA） and empty plasmid （pAVU6 ＋ 27 ） were transfected into human colon carcinoma cell line HCT116 with DOTAP method, respectively named as group C and group B. The positive transfected cell clones were screened with G418. The ceils receiving no plasmid transfection served as control （ group A）. Tumorigenicity and tumor growth of transfected cells were studied in a mouse model. VEGF expression and microvessel density （MVD） in tumor tissue were measured by immunohistochemistry. Results The mean volume and weight of the implanted tumor in group C [ （0. 169±0.009） cm^3, （0. 192 ±0. 022） g ] were significantly lower than group A [ （0.256 ±0. 016 ） cm3, （0.324 ± 0.026 ） g ] and group B [ （0.248 ± 0.014） cm^3, （0. 316 ± 0.015 ） g ] （P 〈 0. 05 ）. The protein expressions of VEGF in group C were significantly decreased as compared with those in group A and group B （P 〈 0. 05 ）, but no significant difference between group A and group B （P 〉 0.05）. Moreover, MVD in group C was also decreased as compared with that in group A and group B （P 〈 0. 05 ）, but no significant difference between group A and group B （P 〉 0.05）. There was a positive correlation between VEGF and MVD （r = 0.810, P 〈 0. 01 ）. Gonelusion Silencing VEGF gene can decrease VEGF gene expressions, suppress tumor angiogenesis and inhibit tumor growth in nude mice beating human colon cancer cell line HCT116.

关 键 词：基因沉默 血管内皮生长因子 移植瘤 血管生成 

分 类 号：R394-33[医药卫生—医学遗传学] R73-362[医药卫生—基础医学]