多效生长因子基因沉默抑制PTEN基因敲除细胞的增殖

Inhibition of proliferation of Pten^(-/-) cell by pleiotrophin gene silence

目的:在肿瘤抑制基因PTEN缺失的小鼠胚胎成纤维细胞Pten-/-MEF241细胞中,研究多效生长因子(p le iotroph in,Ptn)对细胞增殖的影响。方法:设计并合成可编码针对小鼠Ptn基因的小干扰RNA(siRNA)寡核苷酸,构建至pS ilencerTM3.1-H1载体,将载体转染进Pten-/-MEF241细胞中,获得稳定表达细胞克隆株,通过Northern印迹检测Ptn基因表达被抑制的情况,根据细胞生长曲线检测沉默Ptn基因对Pten-/-MEF241细胞生长的影响。结果:获得的稳定克隆株中,与对照细胞相比,Ptn基因的表达在转染Ptn siRNA-B的3株细胞中均得到了有效的抑制,而在转染Ptn siRNA-C的2株细胞中抑制效果较差。生长曲线结果显示,在Pten-/-MEF241细胞中,沉默Ptn基因能够减缓Pten-/-MEF241细胞的生长速度。结论:本研究获得了可有效抑制Ptn基因的小干扰RNA,证明沉默Ptn基因可抑制PTEN基因缺失细胞的增殖,提示Ptn可作为治疗具有PTEN基因突变的肿瘤的药物靶标。

Objective： To analyze the effect of pleiotrophin （Ptn） gene silencing on the proliferation of Pten null mouse embryo fibroblast cells. Methods：pSilencer^TM3. 1-H1 vectors encoding siRNAs against Ptn were stably transfected into a Pten null cell line Pten^-/- MEF241. Cells were then subjected to Northern blots to examine the knocking-down abilities of the Ptn siRNAs, and effects of Ptn gene silencing on the proliferation of Pten^-/- cell were quantified by measuring cell growth curves. Results： The expression of Ptn in clones stably transfected with Ptn siRNA-B was significantly inhibited, whereas the clones stably transfected with Ptn siRNA-C were less inhibited. The growth rates of clones stably transfected with Ptn siRNAs were significantly decreased,indicating that reduction of Ptn expression by siRNA could inhibit the growth of Pten^-/- cells. Condusion： siRNAs against Ptn were designed and tested, and a siRNA which specific targeted Ptn was obtained. Silence Ptn gene significantly inhibits the growth of Pten null cells, suggesting that Ptn can be a drug target for treating tumors with Pten mutation.