Niu Jian, Qian Hai-Xin, Li Xiang-Nong, Han Ze-Guang
Department of General Surgery, The First Affiliated Hospital,Xuzhou Medical College, Xuzhou, Jiangsu, 221004, P. R. China.
Ai Zheng. 2007 Jul;26(7):703-8.
BACKGROUND & OBJECTIVE: Using small interfering RNA (siRNA) to inhibit mammal gene expression becomes an effective technique in studying gene function. This study was to investigate the effect of insulin-like growth factor 1 receptor (IGF1R) siRNA on the growth of human liver cancer SMMC7721 cell xenograft in nude mice.
siRNA targeting IGF1R was designed, and plasmid SMMC7721-IGF1R-siRNA was constructed and transfected into SMMC7721 cells (SMMC7721-IGF1R-siRNA cells); the cells transfected with SMMC7721-IGF1R-mutation (SMMC7721-IGF1R-mutation cells) were used as negative control, and untransfected cells as empty control. Stable cell clones were screened by G418, and transplanted into nude mice to establish cancer xenograft. Tumor growth was monitored. Tumor morphology was observed with HE staining. The expression of IGF1R protein in tumor tissues was detected by Western blot. Microvessel density (MVD) in tumor tissues was detected by SP immunohistochemistry. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay.
The tumor volume was significantly smaller in SMMC7721-IGF1R-siRNA group than in SMMC7721-IGF1R-mutation group and SMMC7721 group (P < 0.05). Necrosis and cell apoptosis were found in SMMC7721-IGF1R-siRNA group. The expression of IGF1R protein was significantly lower in SMMC7721-IGF1R-siRNA group than in SMMC7721-IGF1R-mutation group and SMMC7721 group (P < 0.05). MVD was significantly lower in SMMC7721-IGF1R-siRNA group than in SMMC7721-IGF1R-mutation group and SMMC7721 group (11.3+/-4.4 vs. 36.7+/-7.6 and 28.4+/-6.5, P < 0.05). The apoptosis rate of tumor cells was significantly higher in SMMC7721-IGF1R-siRNA group than in SMMC7721-IGF1R-mutation group and SMMC7721 group [(50.2+/-6.4)% vs. (5.4+/-1.0)% or (6.0+/-2.1)%, P < 0.05].
IGF1R siRNA can inhibit the growth of SMMC7721 cell xenograft in nude mice.
利用小干扰RNA（siRNA）抑制哺乳动物基因表达已成为研究基因功能的有效技术。本研究旨在探讨胰岛素样生长因子1受体（IGF1R）siRNA对人肝癌SMMC7721细胞裸鼠异种移植瘤生长的影响。
设计靶向IGF1R的siRNA，构建质粒SMMC7721-IGF1R-siRNA并转染至SMMC7721细胞（SMMC7721-IGF1R-siRNA细胞）；将转染SMMC7721-IGF1R突变体的细胞（SMMC7721-IGF1R-突变体细胞）作为阴性对照，未转染的细胞作为空白对照。通过G418筛选稳定细胞克隆，并移植到裸鼠体内建立癌异种移植瘤。监测肿瘤生长情况。用苏木精-伊红（HE）染色观察肿瘤形态。采用蛋白质免疫印迹法检测肿瘤组织中IGF1R蛋白的表达。用免疫组织化学链霉菌抗生物素蛋白-过氧化物酶（SP）法检测肿瘤组织中的微血管密度（MVD）。采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法（TUNEL）检测细胞凋亡。
SMMC7721-IGF1R-siRNA组肿瘤体积明显小于SMMC7721-IGF1R-突变体组和SMMC7721组（P<0.05）。SMMC7721-IGF1R-siRNA组出现坏死和细胞凋亡。SMMC7721-IGF1R-siRNA组IGF1R蛋白表达明显低于SMMC7721-IGF1R-突变体组和SMMC7721组（P<0.05）。SMMC7721-IGF1R-siRNA组MVD明显低于SMMC7721-IGF1R-突变体组和SMMC
