反义血管内皮细胞生长因子基因转染在调节人肺巨细胞癌血管生成及肿瘤生长和转移中的作用

目的　探讨反义血管内皮细胞生长因子 (VEGF)基因转染在减少肿瘤细胞内源性血管内皮细胞生长因子分泌 ,调节肿瘤血管生成和肿瘤生长转移中的作用。方法　利用脂质体法将反义基因转染到高转移性人肺癌细胞 (PG) ,以转基因肿瘤细胞培养上清刺激人脐静脉内皮细胞 ,进行噻唑蓝 (MTT)和3H胸腺嘧啶 (3HTdR)掺入实验 ;并将转基因肿瘤细胞接种于裸鼠体内 ,应用免疫组织化学法检测肿瘤内微血管密度 (MVD) ,探讨MVD与肿瘤生长转移的关系。结果　反义VEGF基因的转染 ,使肿瘤细胞VEGF分泌减少 ,其培养上清刺激人脐静脉内皮细胞 (HUVEC)生长活性较空载体组减弱 ,HUVEC之DNA合成减少 ,裸鼠移植瘤内MVD为 41个± 9个 ,空载体组为 5 8个± 10个 ,两组比较t=2 715 ,P <0 .0 5。结论　反义VEGF基因的转染使肿瘤细胞分泌VEGF能力下降 ,肿瘤血管生成能力降低 ,这在肿瘤的生长和转移调节中有重要意义。

Regulatory effect of antisense VEGF_(121) cDNA transfection on angiogenesis and metastasis of human lung giant cell carcinoma

Objective To study the regulatory effect of antisense VEGF 121 cDNA transfection on endogenous VEGF secretion and angiogenesis of human metastatic lung carcinoma cell line PG and explore the significance of microvessel density (MVD) in tumor growth and metastasis. Methods The eukaryotic expression vectors bearing antisense VEGF 121 cDNA was transfected into PG cells. Human umbilical vein endothelial cells (HUVEC) were cultured in conditioned mediums from transfected cells, and proliferation was determined by methyl thiazolyl tetrazolium (MTT) and 3H thymidine incorporation ( 3H TdR) assays in vitro. Microvessel density (MVD) in xenografted tumors in nude mice was analyzed by immunohistochemistry. Results The transfectant of antisense VEGF 121 cDNA exhibited a reduction in VEGF secretion. HUVEC grown in conditioned medium from the antisense VEGF transfected cells exhibited a decrease in capacities of DNA syntheses and cell proliferation. MVD of tumor with transfected antisense VEGF gene was significantly lower than that in control vector. Conclusion Antisense VEGF gene transfection can inhibit vascular endothelial cell proliferation in vitro and tumor angiogenesis in vivo, which may explain its inhibitory effects on tumor growth and metastasis.