VEGF165表达载体的构建及其对人胃癌生长的作用

目的构建血管内皮生长因子(vascular endothelial growth factor, VEGF165）真核表达载体，研究其对胃癌生成的作用. 方法用DNA重组方法，将编码VEGF165的全长cDNA克隆于pcDNA3载体中，构建VEGF165 mRNA真核表达载体；用阳性脂质体介导的基因转染技术，将重组体转入人胃癌细胞（SGC-7901）省系；观察转染细胞的细胞周期、增殖能力及致瘤生长情况等生物学指标. 结果斑点杂交、间接免疫荧光等分析显示，正义VEGF基因转染技术可使VEGF的表达得到明显地加强. 与未转染细胞相比，转染细胞的G2/M期细胞增加(0.44)而S期细胞减少(0.17)，克隆形成率(9.0%)明显高于未转染细胞(4.0%). 瘤细胞接种裸鼠后33 d，过表达VEGF人胃癌细胞所致的移植瘤体积（2351±638) mm3明显大于未转染细胞所致的移植瘤体积（1534±363) mm3. 结论 VEGF可以通过加强肿瘤组织血管生成而促进肿瘤的生长，另外，VEGF的表达可能与细胞增殖能力有关.

Construction of eukaryotic expression vector of VEGF165 gene and its effect on oncogenesis of human gastric carcinoma

AIM　To construct a eukaryotic expression vector of VEGF165 (vascular endothelial growth factor) gene, and to more directly establish the role of VEGF in the oncogenesis of human gastric carcinoma. METHODS　VEGF165 sense RNA expression vector was constructed by inserting the VEGF165 cDNA into SGC-7901 cells by lipofect technique. Then the cell cycle, proliferative ability in vitro and growth in nude mice of transfected cells were examined. RESULTS　Introduction of the VEGF sense construct into SGC-7901 cells resulted in a marked increase in the expression of VEGF-specific mRNA and protein by dot blot and immunofluorescence staining analysis in transfected tumor cells. Cell cycle analysis showed that, compared with the parental cells the number of transfected cells had an increase (0.44) in G2 phase and a decrease (0.17) in S phase, and its colony forming rate (9.0%) was higher than that of the control cells (4.0%); The volume of tumor（2351±638) mm3 in the nude mice inoculated with the cells transfected by VEGF165 expression vector greatly increased in comparison with that （1534±363) mm3 in nude mice inoculated with SGC-7901 cells. CONCLUSION　As starting angiogenesis, VEGF might promote the growth of solid tumor; in addition, it might correlate with the proliferation of tumor cell.