靶向Skp2基因siRNA对人大肠癌裸鼠移植瘤细胞增殖和凋亡的影响

Influence of Skp2-Targeted siRNA on Proliferation and Apoptosis of Human Colorectal Cancer Xenografts in Nude Mice

目的:应用RNA干扰(RNAi)技术沉默Skp2(Skp2)基因,研究其对人大肠癌裸鼠移植瘤细胞增殖和凋亡的影响。方法:建立裸鼠大肠癌皮下移植瘤模型,随机分为3组:PBS组,阴性对照序列组(Skp2-NC组),RNA干扰组(Skp2-siRNA组)。分别于瘤体内局部注射PBS、腺病毒Ad-Skp2-NC、腺病毒Ad-Skp2-siRNA,每3d注射1次,共3次。4周后分离瘤体,观察肿瘤抑瘤率并绘制生长曲线。采用蛋白印迹技术检测瘤体中Skp2、p27蛋白表达;免疫组化法检测肿瘤内增殖细胞核抗原(PCNA)表达量变化;原位末端标记(TUNEL)法检测肿瘤细胞凋亡。结果:Skp2-siRNA组抑瘤率为32.40%,与PBS组和Skp2-NC组比较差异有统计学意义(P<0.05);Skp2-siRNA组Skp2蛋白表达下调,p27蛋白表达增多;PCNA表达量显著低于PBS组和Skp2-NC组;Skp2-siRNA组凋亡细胞相对光密度值为(255.73±1.77)%,与PBS组(100.00±0.47)%和Skp2-NC组(93.07±1.17)%相比,明显增高。结论:Skp2-siRNA能有效抑制裸鼠体内人大肠癌SW480细胞株增殖并促进其凋亡,具有显著的抑瘤效果。

Objective： To investigate the effect of targeting Skp2-siRNA on the proliferation and apopto- sis of human colorectal cancer SW480 cell xenografts in nude mice. Methods： Human colorectal cancer models were established in nude mice. The nude mice were randomly divided into three groups： PBS group, negative control group （Skp2-NC group）, RNA interference group （Skp2- siRNA group）, which were treated with PBS, Ad-Skp2-NC, and Ad-Skp2-siRNA respectively once per three days for three times. The status of xenografted nude mice was observed for contin- uous four weeks, and then the tumor growth inhibitory rate （IR） was calculated and growth curve was created. The expression of Skp2 and p27 proteins were analyzed by Western blotting, proliferating cell nuclear antigen （PCNA） protein expression in tumors was detected by immuno-histoehemistry （IHC）, and TUNEL staining was used to detect apoptosis. Results： Compared with that in PBS group and Skp2-NC group, tumor growth was significantly inhibited by Skp2- siRNA and IR was 32. 40%. In Skp2-siRNA group, the expression levels of Skp2 and PCNA were lower, and p27 expression was higher than those in the PBS and Skp2-NC groups （all P〈 0.05）. The relative optical density （ROD） of apoptotic cells in the Skp2-siRNA group was （255.73±1.77）%, which was significantly higher than （100. 00±0. 47）% in PBS group and （93.07±1. 17）% in Skp2-NC group （P〈0.05）. Conclusion： Skp2-siRNA can effectively suppress the tumor growth by inhibiting the proliferation and promoting the apoptosis of SW480 cell xenografts in nude mice.