血管内皮生长因子D促进胃癌淋巴管生长

目的研究血管内皮生长因子D（VEGF-D）与胃癌淋巴管转移之间的关系。方法采用反转录-聚合酶链反应（RT-PCR）从人胃癌旁正常组织中扩增人VEGF-D全长cDNA，经T-A克隆酶切鉴定及测序得到完整的序列后，亚克隆并构建pEGFP／VEGF-D真核表达载体，转染低表达VEGF-D的胃癌细胞株SGC7901，通过体外G418抗生素筛选得到高表达VEGF-D的肿瘤细胞克隆，用这种高表达VEGF-D的胃癌细胞接种于裸鼠皮下，用淋巴管内皮细胞透明质酸盐受体（LYVE-1）行免疫组织化学染色观察肿瘤淋巴管密度和形态。结果对照组和转染pEGFP／VEGF-D组肿瘤的重量分别为（1．13±0．40）g和（2．24±0．82）g，两组差异有统计学意义（P〈0．05）。肿瘤组织内的淋巴管密度分别为2．89±1．32和5．74±1．30，两组差异有统计学意义（P〈0．01）。周边肿瘤组织存在扩张的功能性淋巴管。结论VEGF-D在胃癌中可能通过主动促进淋巴管生长来促进肿瘤生长和远处转移。

Vascular endothelial growth factor D promoting the growth of lymphatic vessel in gastric carcinoma

OBJECTIVE: To investigate the relationship between vascular endothelial growth factor D (VEGF-D) and metastasis of lymphatic vessel in gastric carcinoma. METHODS: The human VEGF-D cDNA was amplified from total RNA isolated from human normal gastric tissue, then it was inserted into T-A clone plasmid and subcloned into pEGFP eukaryotic expression vector. After the full-length sequence expected was confirmed by enzymatic digestion and sequencing,the human gastric carcinoma cell line SGC7901, which expressed a low level of VEGF-D, was transfected with the pEGFP/VEGF-D expression vector. Stable SGC7901 clones with high expression of VEGF-D were selected in vitro with G418, which were then combined and subcutaneously injected into nude mice to observe the density and morphology of lymphatic vessel. The outcomes were later compared with those of SGC7901 cells transfected with null vector(pEGFP) by immunostaining with a specific antibody LYVE-1. RESULTS: The average weight of tumors in the pEGFP group (1.13+/-0.40) g at day 35, was significantly lower than that in the pEGFP/VEGF-D group (2.24+/-0.82)g (P<0.05). The lymphatic vessel density (LVD) in the pEGFP group (2.89+/-1.32) was significantly lower than that in the pEGFP/VEGF-D group (5.74+/-1.30)(P<0.01). There were dilated functional lymphatic vessels around the tumor margin. CONCLUSION: VEGF-D may promote the growth and metastasis of tumor in gastric carcinoma by increasing the growth of lymphatic vessels.