Ki67基因干扰对裸鼠人肾癌细胞移植瘤的抑制作用

The Effects of Replication-deficient Recombinant Adenovirus Expressing siRNA Targeting the Ki67 Gene on Implanted Human Renal Cell Carcinoma in Nude Mice

目的：探讨靶向Ki67基因干扰腺病毒（Ad—Ki67）对裸鼠人肾癌移植瘤Ki-67基因表达和肿瘤生长的影响。方法：建立人肾癌移植瘤模型，瘤体内注射Ad—Ki67，定期测量肿瘤体积，激光共聚焦显微镜观察移植瘤组织Ki-67抗原表达，原位末端标记法（TUNEL）检测肿瘤细胞凋亡。结果：Ad—Ki67能将Ki67基因有效沉默，Ad—Ki67组和Ad—EGFP组Ketr-3细胞Ki-67抗原表达水平分别为对照组的（78．7±6．5）％、（95．4±8．6）％；与对照组细胞凋亡阳性率（10．7±2．4）％比较，Ad—Ki67、Ad—EGFP组分别为（43．7±3．6）％和（21．8＋2．5）％，表明Ad—Ki67能有效诱导肿瘤细胞凋亡；Ad—Ki67能显著抑制肿瘤的生长，接种5周后Ad—Ki67组肿瘤体积为（469．5±41．6）mm2，Ad—EGFP组为（664．3．5±47．8）mm2，PBS组为（884．9±52．5）mm2。结论：靶向Ki67基因的干扰腺病毒Ad—Ki67对裸鼠肾癌移植瘤有显著的治疗效果，为治疗肾癌提供新的平台。

Objective： To study the effects of replication-deficient recombinant adenovirus vector expressing small interfering RNA targeting the Ki67 gene （Ad-Ki67） on Ki67 gene expression and the growth of implanted human renal cell carcinoma in nude mice. Methods： BALB/C nude mice were inoculated subcutaneously with Kerr-3 cells to establish the nude mouse renal cell carcinoma model. After the tumor-bearing nude mice were injected Jntratumorally with Ad-Ki67, the tumor size was measured at different intervals to observe the anti-tumor effect. The protein expression of Ki-67 in the tumor tissue was observed by laser scanning confocal microscopy, the CD34 protein expression in the tumor tissue was evaluated by immunohistochemistry, and the apoptosis of tumor xenografts was measured by in situ end labeling technique （TUNEL）. Results： Ki67 staining positivity was effectively reduced in tumor tissue from nude mice treated with Ad-Ki67 compared with that in tumors treated with Ad-EGFP or PBS. The apoptotic rate in the Ad-Ki67 treatment group was 43.7%±3.6%, significantly higher than that in the other two groups （10.7%±2.4% for PBS and 21.8%±2.5% for Ad-EGFP. The mean tumor size in the Ad-Ki67 treatment group was 469.5±41.6 mm2 after treatment, much smaller than that in the Ad-EGFP group （664.3＋47.8mm3, P〈0.01） and the PBS group （884.9±52.5mm3, P〈0.01）. Conclesion： Recombinant adenovirus vector expressing siRNA targeting the Ki67 gene has significant therapeutic effects on transplanted human renal carcinoma in nude mice, suggesting that it may be a novel tool for gene therapy of human renal cell carcinoma.