Cancer Center, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China.
Hum Gene Ther. 2009 Feb;20(2):103-11. doi: 10.1089/hum.2008.098.
Angiogenesis plays an important role in the growth of solid tumors. To date, no information has been acquired on the effectiveness of gene therapy in the orthotopic lung cancer model of syngeneic immunocompetent mice treated with an angiogenesis inhibitor. Here, we report the establishment of such a model in which Lewis lung carcinoma (LL/2) cell suspensions were orthotopically inoculated into the lung parenchyma of C57BL/6 mice, which were also injected with a recombinant adenoviral vector delivering the human endostatin gene (Ad-hE). We found that orthotopic implantation of LL/2 cells into the lung parenchyma produced a solitary tumor nodule in the lung followed by remote mediastinal lymph node metastasis. Conditioned medium from Ad-hE-transfected LL/2 cells apparently inhibited proliferation of human umbilical vein endothelial cells (HUVECs). The level of endostatin protein in serum could be identified by enzyme-linked immunosorbent assay. Treatment with Ad-hE resulted in inhibition of tumor growth and prolongation of survival time of tumor-bearing mice. Immunohistochemical analysis revealed that intratumoral angiogenesis was significantly suppressed. Furthermore, the finding of angiogenesis inhibition was also supported by measuring the number of circulating endothelial cells (CECs). Apoptotic cells were found to be increased within tumor tissues from mice treated with Ad-hE. In addition, treatment with Ad-hE combined with cis-diamminedichloroplatinum(II) (cisplatin) enhanced antitumor activity. These observations provide further evidence of the antitumor effect of endostatin gene therapy, and may be of importance for further exploration of potential application of this combined approach in the treatment of human lung cancer as well as other solid tumors.
血管生成在实体瘤的生长中起着重要作用。迄今为止，尚无关于在接受血管生成抑制剂治疗的同源免疫功能正常的小鼠原位肺癌模型中基因治疗效果的信息。在这里，我们报告了这样一种模型的建立，其中将 Lewis 肺癌（LL/2）细胞悬浮液原位接种到 C57BL/6 小鼠的肺实质中，同时还注射了携带人内皮抑素基因（Ad-hE）的重组腺病毒载体。我们发现，将 LL/2 细胞原位植入肺实质中会在肺部产生单个肿瘤结节，随后会发生远处纵隔淋巴结转移。来自 Ad-hE 转染的 LL/2 细胞的条件培养基明显抑制了人脐静脉内皮细胞（HUVEC）的增殖。通过酶联免疫吸附试验可以鉴定血清中内皮抑素蛋白的水平。用 Ad-hE 治疗可抑制肿瘤生长并延长荷瘤小鼠的生存时间。免疫组织化学分析显示肿瘤内血管生成明显受到抑制。此外，通过测量循环内皮细胞（CECs）的数量也支持了血管生成抑制的发现。在用 Ad-hE 治疗的小鼠的肿瘤组织中发现凋亡细胞增加。此外，用 Ad-hE 联合顺二氨二氯铂(II)（顺铂）治疗可增强抗肿瘤活性。这些观察结果进一步证明了内皮抑素基因治疗的抗肿瘤作用，并且对于进一步探索这种联合方法在治疗人类肺癌以及其他实体瘤中的潜在应用可能具有重要意义。
