重组人内皮抑素腺病毒抗肿瘤实验研究

Inhibition of tumor growth and metastasis via local administration of recombinant human endostatin adenovirus

目的肿瘤生长具有血管依赖性。内皮抑素为胶原X羧基末端裂解片段,是重要的内源性血管抑制因子。实验中利用重组人内皮抑素腺病毒(recombinanthumanendostatinadenorirus,Ad-hEndo)在肿瘤局部给药以探索其抗血管基因治疗的可行性。方法以Ad-hEndo感染体外培养肿瘤细胞,观察重组蛋白表达及其对培养的血管内皮细胞的抑制效应;在裸鼠A549肺癌模型中瘤内注射重组病毒,观察肿瘤抑制效应、剂量依从效应和毒副反应。结果不同感染复数的Ad-hEndo感染肿瘤细胞均表达重组内皮抑素蛋白,并能抑制血管内皮细胞的生长。动物实验中Ad-hEndo治疗组肿瘤体积及肺转移结节数明显低于对照组,且转移数与治疗剂量负相关。结论以腺病毒为载体的肿瘤局部血管基因治疗能抑制肿瘤新生血管形成进而有效抑制肿瘤生长和转移,其效应具有剂量依从性。

Objective The growth and metastasis of solid tumors are dependent on angiogenesis. Endostatin, the C terminal proteolytic fragment of collagen XⅧ, is a potent endogenous angiogenesis inhibitor. The authors designed a topical antiangiogenic gene therapy with recombinant human endostatin adenovirus (Ad hEndo) and assessed its effects on the inhibition of angiogenesis in vitro, and tumor growth and metastasis in vivo. Methods Malignant cells (A549) were infected with Ad hEndo. The expression of recombinant protein and the inhibition of cultured human umbilical vein edothelial were investigated. Immunodeficient A549 nude mice were treated with intratumoral injection of Ad hEndo, the empty vector Ad control or saline (NS). The dose response, side effects, and serum concentration of endostatin were observed. Results Recombinant endostatin protein was detected in the infected tumor cells with different MOI Ad hEndo and its inhibitory effect on endothelial cells growth was shown. In animal study, the volume of tumor and the number of pulmonary metastatic lesions in the Ad hEndo treatment group were significantly smaller than those in the control groups ( P <0.05).Conclusion The present findings provide evidence of the anti tumor effects of the endostatin and may be important for the further use of it in topical antiangiogenic gene therapy of cancer.