Angiostatin and endostatin gene therapy on murine lung metastases model utilizing cationic vector-mediated intravenous gene delivery

通过产生抗血管生成因子来抑制血管生成应该是癌症基因治疗的一个可行的方法。最近，非病毒载体被认为是病毒的替代品。在本研究中，我们观察了静脉注射内皮抑素基因联合GL67/DOPE或PEI22K是否能抑制小鼠肺转移瘤的发展。利用表达内皮抑素的小鼠NFSA Y83纤维肉瘤细胞稳定的转染体，检测表达的内皮抑素对肺转移瘤生长的抑制作用。静脉注射内皮抑素基因与GL67/DOPE或PEI22K复合后，小鼠各脏器的RT-PCR分析表明，肺的mRNA表达水平最高，其次是心、脾、肾和肝脏。此外，静脉注射复合物后的全肺免疫组织化学显示，转基因细胞定位于包括呼吸细胞在内的多种细胞类型。在纤维肉瘤细胞接种后3天或7天静脉注射内皮抑素基因复合GL67/DOPE或PEI22K，2周后可显著抑制肺转移的形成(与空质粒复合各载体相比，肺转移数目减少87~98%，肺重量减少53~59%)。这些结果表明，使用阳离子载体介导的基因转移，静脉注射抗血管生成基因，在治疗播散性肺癌方面具有潜在的用途。

Inhibition of angiogenesis by production of antiangiogenic factors should be a viable approach for cancer gene therapy. Recently, nonviral vectors have been suggested as an alternative to viruses. In this study, we investigated whether intravenous administration of endostatin gene complexed with GL67/DOPE or PEI22K could inhibit the development of lung metastatic lesions in murine models. The biological activity of the expressed endostatin was also determined by its ability to prevent the growth of lung metastases using stable transfectants from murine NFSa Y83 fibrosarcoma cells expressing endostatin. RT-PCR analysis in various organs of mice after intravenous injection of endostatin gene complexed with GL67/DOPE or PEI22K showed that the highest levels of mRNA expression were found in the lung, followed by heart, spleen, kidney and liver. In addition, immunohistochemistry of whole lungs after intravenous injection of the complexes showed that transfected cells were localized in a variety of cell types, including respiratory cells. Single intravenous injection of endostatin gene complexed either GL67/DOPE or PEI22K at the time of 3 days or 7 days from fibrosarcoma cells implantation resulted in striking inhibition of formation of lung metastases after 2 weeks (compared to empty plasmid complexed each vector, 87-98% reduction in the number of lung metastases and 53-59% reduction in lung weight). These results demonstrated the potential usefulness of intravenous delivery of an antiangiogenic gene, using cationic vector-mediated gene transfer, for treatment of disseminated cancers in lung.