内皮抑素基因转移对乳腺癌细胞生长影响的体内和离体研究

目的：探讨内皮抑素(ES)基因转移在乳腺癌抗血管新生中的作用。 方法: 通过建立逆转录病毒介导的ES基因转移系统，用ES病毒转染人乳腺癌细胞系MDA-MB-231。以聚合酶链反应（PCR）、MTT法和裸鼠成瘤实验分析ES的生物学特性及其功能。 结果： 脂质体转染与交互感染策略获得ES病毒生产细胞；以ES病毒转染MDA-MB-231细胞后，经PCR分析显示其内有ES基因整合并持续表达，其分泌的ES能明显抑制内皮细胞EA.hy926的增殖(P<0.05)，但对肿瘤细胞的离体生长无明显影响（P>0.05）；裸鼠皮下移植瘤模型表明，ES基因表达可明显抑制MDA-MB-231细胞的生长(P<0.01)；实验组的肿瘤微血管密度（MVD）和血管内皮生长因子(VEGF)表达低于对照组(P<0.05)。 结论: 逆转录病毒载体介导的ES基因在乳腺癌细胞中可有效表达，能明显抑制血管内皮细胞生长，并通过旁分泌方式抑制血管新生，具有显著的抗肿瘤生长的作用。

The inhibitory effects of endostatin gene transfer on the growth of breast cancer cells in vivo and in vitro

AIM: To investigate the therapeutic action of secreted endostatin (ES) on breast cancer cells. METHODS: Retroviral-mediated endostatin gene was transferred to breast cancer cell line MDA-MB-231. The ES biological properties and function were evaluated by polymerase chain reaction (PCR), MTT and a murine xenograft model. RESULTS: After retroviral transduction, endostatin genetically modified breast tumor cells were confirmed by PCR, and the integration and durative expression of endostatin gene was successfully committed. Compared with controls, endostatin secreted by genetically modified cells markedly inhibited endothelial cell proliferation (P<0.05) while the influences on the growth of MDA-MB-231 cell line in vitro were not found (P>0.05). The results of the transplanted subcutaneous tumor model in nude mice suggested that the subcutaneous growth of MDA-MB-231 was significantly inhibited by the expression of endostatin gene (P<0.05). In experimental groups, the tumor microvascular density (MVD) and VEGF expression were decreased. CONCLUSION: Retroviral-mediated overexpression of endostatin inhibits the proliferation of vascular endothelial cells and angiogenesis that associated with tumor growth in vivo via the paracrine pathway, which has a potential effect in the angiostatic gene therapy for breast cancer.