靶向IGF-1基因的siRNA抑制胶质瘤生长的体内外实验研究

Experimental Study of Suppressing Effect of siRNA Targeting IGF-1 on Growth of Glioma in Vitro and in Vivo

目的观察靶向IGF-1基因的小干扰RNA（siRNA）在体内和体外对胶质瘤生长的抑制作用。方法采用逆转录．聚合酶链反应（RT-PCR）和Western印迹测定干扰后IGF-1的表达水平；采用Transwell体外侵袭试验进行细胞体外的侵袭力分析；用流式细胞仪检测细胞凋亡率；应用裸鼠成瘤实验测定IGF-1基因表达下调后胶质瘤C6细胞在体内致瘤能力的改变。结果靶向IGF-1基因的siRNA可以有效抑制IGF-1基因的表达，使IGF—1 mRNA表达减少50％～80％，蛋白表达减少60％，流式细胞术检测细胞凋亡率明显提高（P〈0．01），降低了在裸鼠体内成瘤的能力。结论siRNA介导的IGF-1基因下调可明显抑制胶质瘤细胞的生长。IGF-1可以作为胶质瘤基因治疗的一个新的靶点。

Objective To investigate the inhibitory effect of small interference RNAs （siRNAs） targeting IGF-1 on growth of glioma in vitro and in vivo. Methods RT-PCR and Western blotting were used to analyze the IGF-1 expression. The invasiveness of C6 cell in vitro was measured quantitatively by the matrigel invasion assays; flow cytometry was performed to analyze cell apoptosis. The ability of the tumorigenicity in nude mice was measured. Results The expression of IGF-1 could be suppressed effectively by siRNA targeting IGF-1. The expression of IGF-1 mRNA decreased from 50% to 80 %. The expression of IGF-1 protein decreased by 60%. Cell apoptosis could be induced from 1.98 % in the control group to 15.07 % in the siRNA group. The ability of the tumorigenicity in nude mice was reduced. Conclusions Down-regulation of IGF-1 by sIRNA suppresses glioma cell growth markedly. The successful knockdown of IGF-1 expression by siRNA implicates that IGF-1 may be a new target for gene therapy of glioma.