EGFP标记的人肺癌裸鼠原位移植模型的建立

Establishment of Orthotopic Lung Cancer Model Expressing Enhanced Green Fluorescent Protein

背景与目的小鼠活体分子成像模型可以连续实时监测活体肿瘤的变化。本研究拟通过外科原位移植法建立表达绿色荧光蛋白的肺癌裸鼠原位移植模型并探讨其肿瘤生物学特性,从而建立一个良好的肺癌动物实验研究平台。方法利用逆转录病毒转染法将增强型绿色荧光蛋白基因导入人肺癌大细胞系NCI-H460,采用外科原位移植法建立肺癌原位移植模型。定期通过小动物活体荧光成像系统观察肿瘤生长,利用相关性检验分析荧光面积和肿瘤体积之间的相关关系,并观察原位移植术后裸鼠的生存期和肿瘤转移情况。结果模型建立后1周通过皮瓣在荧光体视镜下可观察到肺部肿瘤的绿色荧光,成瘤率为100%。荷瘤裸小鼠平均生存期为34.2天。解剖裸鼠观察到肿瘤侵及对侧肺、纵隔及肺门淋巴结、胸膜和膈肌,转移率分别为87.5%、75%、25%和12.5%。肿瘤体积和荧光面积具有相关性(r=0.873,P=0.001)。结论外科原位移植法建立的表达EGFP的裸鼠肺癌原位模型是肺癌临床前研究的理想的实验工具。应用小动物活体荧光成像系统能够定量客观评价肿瘤在动物体内的生长、侵袭和转移,该模型可应用于肺癌的基础研究和新药开发。

Background and objective In vivo molecular imaging with mouse model could continuously and in real-time monitor the changes of the tumor. The aim of this study is to establish stable enhanced green fluorescent protein （EGFP） expressing NCI-H460 cell lines and relevant mouse model via orthotopic transplantation, and to study the characteristic of this model and the quantitative detection method of the primary tumor and metastatic lesions. Methods Human lung cancer NCI-H460 cells were transfected with retroviral vector containing the EGFP. Stable high-level expression of EGFP was maintained in the subcutaneously-growing tumors. Fragments of the subcutaneously growing tumor, which were comprised of EGFP-expressing cells, were implanted by surgical orthotopic implantation （SOI） in the lung of nude mice. The dynamic growth of orthotopic tumor was observed using in vivo fluorescence imaging. The correlation of fluorescence area and tumor volume was tested. Results After the model established, green fluorescent can be observed through the flap in day 7. Tumor formation rate was 100%. Mean survival time of tumor-bearing nude mice was 34.2 days. The metastasis sites were the contralateral lung, mediastinal and hilar lymph nodes, pleura and diaphragm; metastasis rates were 87.5%, 75%, 25% and 12.5%, respectively. Tumor volume and fluorescence area was correlated （r=0.873, P=0.001）. Conclusion The nude mouse model bearing orthotopic human lung cancer expressing EGFP has been successfully established. The model might be used for further molecular studies on tumor metastasis, angiogenesis and also be applied to anti-tumor drug screening in preclinical stage.