血管内皮生长因子受体KDR胞外区基因对裸鼠人膀胱癌生长的影响

目的研究血管内皮生长因子(VEGF)受体KDR胞外区基因对肿瘤新生血管的抑制作用.方法采用脂质体转染技术,将KDR胞外区基因的真核表达质粒pcDNA3.1/KDRn7转入人膀胱癌EJ细胞,用G418筛选得到稳定表达目的蛋白的细胞克隆,经固相结合实验筛选得到表达与VEGF特异结合的目的蛋白的细胞克隆,阳性细胞克隆进行了RT-PCR鉴定.结果鸡胚测活表明,EJ细胞表达rKDRn7的能抑制鸡胚绒毛尿囊膜的血管形成;表达rKDRn7的EJ细胞株对裸鼠人膀胱癌生长及血管生成明显抑制,实验组的微血管密度(MVD)为12±4,阴性对照组62±11.结论阻断VEGF/KDR信号传导途径能够抑制肿瘤新生血管的形成,延缓肿瘤的生长速度.

Impact of extracellular gene of VEGF receptor KDR on growth of human bladder carcinoma in nude rats

OBJECTIVE: To investigate the anti-angiogenesis activity of the extracellular domain of vascular endothelial growth factor (VEGF) receptor KDR. METHODS: The eukaryotic expression plasmid pcDNA3.1/KDR(n7) of the extracellular domain of KDR was transfected into the human bladder carcinoma EJ cells by lipofactamin technology. Cellular clone that stably expressed the target protein was obtained by G418 screening. The cellular clone that expressed the target protein specifically combined with VEGF was obtained by solid-phase binding assay. The positive cellular clone was identified by RT-PCR. RESULTS: The rKDR(n7) expressed by EJ cells can inhibit the angiogenesis in egg CAM. The EJ cell strain significantly inhibits the growth and angiogenesis of human bladder carcinoma in nude rat. The microvascular density in the experimental group was 12 +/- 4, significantly lower than that in hte negative control group (62 +/- 11). CONCLUSION: Inhibition of the VEGF/KDR signal transmission channel can inhibit the angiogenesis in tumor, thus delaying its growth.