探讨以Tie2为靶点的基因治疗对结肠癌生长及肝转移的抑制作用。

构建表达Tie2胞外可溶性片段(sTie2)的慢病毒载体pLenti-sTie2，建立BALB/C小鼠结肠癌皮下成瘤模型及肝转移模型。经尾静脉注射重组病毒载体，在不同时间点分别测量皮下移植瘤体积、经ELISA法检测小鼠血中sTie2的表达水平。2周后处死小鼠，观察肝转移的情况，并取瘤组织检测血管形成和细胞凋亡指标。采用SPSS 16.0统计学软件进行数据分析。组间的比较采用单因素方差分析。以P<0.05为差异有统计学意义。

经pLenti-sTie2重组慢病毒治疗3 d后，小鼠体内可较高表达sTie2[(1.38±0.19)～(1.52±0.12)g/L]，与空病毒组相比，pLenti-sTie2重组慢病毒能显著抑制移植瘤的生长及结肠癌肝转移灶的形成(P<0.05)。组织病理检测和DNA ladder法检测发现，肿瘤血管生成同样得到有效抑制，促进肿瘤细胞凋亡。

为基于Tie2为靶点的抗血管形成治疗结肠癌及结肠癌肝转移患者提供了实验依据。

To investigate the effect of targeting Tie2 by gene therapy on colonic cancer growth and liver metastases.

pLenti-sTie2 was reconstituted to express extracellular soluble fragment of Tie2 in vivo.Ectopic transplant BALB/C mice model with colonic cancer and colonic cancer liver metastases were established using CT26 cell line.The recombinant vectors were injected through the tail vein.Then, tumor volume was measured and serum sTie2 of mice were detected at different time points, respectively.Two weeks later, mice were sacrificed to detect liver metastases and tumor tissues were collected to detect density of blood vessel and apoptosis of tumor cells.

The sTie2 was stably expressed in serum of mice after injection of pLenti-sTie2 and maintained at high level for above 3 weeks [from(1.38±0.19)to(1.52±0.12)g/L]. Compared with Lentivirus, ectopic tumor growth and the metastases formation in the group treated with pLenti-sTie2, was obviously decreased(P<0.05). Pathology detection and DNA ladder detection found that pLenti-sTie2 therapy could obviously inhibit tumor angiogenesis and promote tumor cell apoptosis.

The present study would provide experimental data for targeting Tie2 gene therapy of colonic cancer and liver metastases.