中文摘要：

研究裸质粒能否转染肺癌相关细胞，且有效表达具有血管形成抑制活性的组织激肽释放酶结合蛋白（Ka1），以及Ka1的表达对体内外肺癌及相关细胞的生物学影响。采用Lipofectamine2000介导质粒对肺癌相关细胞的转染，ELISA法检测Ka1浓度，并考察Ka1对细胞增殖、凋亡和迁移的影响。瘤内直接注射质粒后，观察NCI—H446皮下移植瘤内CD34、Ki-67和E-钙黏蛋白水平变化，以及肿瘤细胞凋亡的情况。转染质粒后。所有受试细胞均可表达Ka1，其中HUVEC的增殖和迁移受到抑制；3种肺癌细胞NCI—H446、NCI．H460和A549的增殖被不同程度地抑制，并出现凋亡现象。体内研究显示，Ka1可以抑制新疗曲；球薪生血管生成及肿瘤细胞增殖，肿瘤生长速度显著降低。因此，可介导Ka1表达的裸质粒可以作为肺癌治疗的候选药物。

英文摘要：

This study is to investigate whether naked plasmid DNA can effectively transfect lung cancer related cells and express human kallistatin, an endogenous protein that inhibits angiogenesis and tumor growth, and to explore the biological activity of the low-level expressed kallistatin to lung cancer in vitro and in vivo. The plasmids were delivered with Lipofectamine 2000 to transfect various lung cancer related cells. Kal expression was determined by ELISA. The biological effects of Kal expression on proliferation, migration and apoptosis rate of the cells were examined. In subcutaneous NCI-H446 xenograft model, pKal was injected directly into tumors, the changes of CD34, Ki-67 and E-cadherin expression were detected with immunohistochemical assay, the tumor apoptosis was analyzed with TUNEL assay. Both the endothelial cell and lung cancer cells could express kallistatin after plasmid transfection. The proliferation and migration of human umbilical vein endothelial cells were inhibited, but the apoptosis rate was not affected. The proliferation rates of all the three tested lung cancer cells, such as NCI-H446, NCI-H460 and A549, were inhibited, and their apoptosis rates were enhanced, but different cells behaved differently. In subcutaneous NCI-H446 xenograft model, intratumor injection of pKal inhibited the growth of lung cancer by reducing angiogenesis and proliferation of tumor cells. In conclusion, this study demonstrated the efficacy of plasmid-mediated expression of kallistatin to lung cancer related cells, thus providing a basis for their clinical application in the treatment of lung cancer.