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 silence Skp2 (Skp2) gene by RNA interference (RNAi) technique and study its effect on the proliferation and apoptosis of human colorectal cancer xenografts in nude mice. Methods: The nude mice model of colorectal cancer subcutaneously transplanted tumor was established and randomly divided into three groups: PBS group, Skp2-NC group and Skp2-siRNA group. PBS, adenovirus Ad-Skp2-NC and adenovirus Ad-Skp2-siRNA were injected into the tumor respectively and injected once every three days for 3 times. After 4 weeks, the tumor was separated and the tumor inhibition rate was observed and the growth curve was drawn. Western blotting was used to detect the expression of Skp2 and p27 in tumor tissues. The expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry. The apoptosis of tumor cells was detected by TUNEL. Results: The inhibitory rate of Skp2-siRNA group was 32.40%, which was significantly lower than that of PBS group and Skp2-NC group (P <0.05). Skp2-siRNA group was down-regulated and p27 protein expression was increased. The relative optical density of apoptotic cells in Skp2-siRNA group was (255.73 ± 1.77)%, which was significantly lower than that in PBS group and Skp2-NC group (100.00 ± 0.47)% vs Skp2-NC group (93.07 ± 1.17)% Compared to significantly higher. Conclusion: Skp2-siRNA can effectively inhibit the proliferation and promote the apoptosis of human colorectal cancer SW480 cell line in nude mice, and has significant anti-tumor effect.