【摘要】 目的:研究慢病毒介导的KDR启动子驱动的胞嘧啶脱氨酶（CD）/胸苷激酶（TK）融合基因系统（FGW-KDRP-CD/TK）对乳腺癌细胞的体内杀伤作用。方法:培养乳腺癌MCF-7细胞,建立裸鼠荷瘤模型。荷瘤后将裸鼠随机分为4组。Ⅰ组:空白对照,荷瘤但不施加任何处理;Ⅱ组:注射慢病毒与前药（5-FC+GCV）;Ⅲ组:仅注射慢病毒;Ⅳ组:仅注射前药。观察肿瘤生长速度,测量瘤体大小及重量;用RT-PCR法鉴定双自杀基因在转基因瘤组织中的表达;取肿瘤组织进行HE及PCNA免疫组化染色;流式细胞技术进行细胞周期检测。结果:第Ⅱ组裸鼠移植瘤的生长显著受到抑制,第Ⅰ、Ⅲ、Ⅳ组肿瘤生长情况无明显差异。经RT-PCR检测发现转基因瘤组织有目的基因的表达。与第Ⅰ组（空白对照组）相比,第Ⅱ组瘤组织的PCNA表达明显下调。流式细胞仪检测细胞周期分析显示治疗后G₁期细胞比率增多,G₂/M期细胞减少。结论:FGW-KDRP-CD/TK联合前药5-FC及GCV在体内可明显抑制移植瘤的生长,细胞周期阻滞,该作用可能与抑制PCNA表达有关。更多还原

【Abstract】 Objective:To evaluate the killing effect of lentivirus mediated CD/TK fusion gene controlled by kinase insert domain-containing receptor （KDR） promoter on human breast cancer cells in vivo.Methods:Nude mice were used as hosts for cell line MCF-7 xenografts to establish the animal model of breast cancer.The tumor-bearing mice were randomly divided into 4 groups. Group Ⅰ were blank controls with tumor-bearing mice with no treatment.Group Ⅱ was injected with lentivirus and prodrug （5-FC+ GCV）.Group Ⅲ was injected with lentivirus.Group Ⅳ was injected with prodrug.Tumor growth rate,tumor size and weight were observed.The expression of double suicide genes in xenograft tumors was examined by RT-PCR.The tumor tissue was analyzed by hematoxylin-eosin staining and PCNA immunohistochemistry.Flow cytometry （FCM） was used for cell cycle analysis.Results:Tumor growth was obviously inhibited in group Ⅱ.But there was no significant difference in tumor growth among group Ⅰ,group Ⅲ,and group Ⅳ.RT-PCR demonstrated the existence of CD/TK gene in genetically modified xenograft tumor cells.The expression of PCNA was lower in tumor tissue of group Ⅱ than in group Ⅰ.Flow cytometry analysis showed that the proportion of G₁ phase cells was increased and the proportion of G₂-M phase cells was decreased.Conclusion:Combined with the prodrug,FGW-KDRP-CD/TK can significantly inhibit the growth of implanted breast cancer cells in nude mice and cell cycle arrest,which may be related to its inhibitory effect on PCNA expression.更多还原