绿色荧光蛋白与荧光素酶双标记肝癌细胞的构建及其在小鼠模型中的应用

Establishment of double-labeled human liver cancer cells of green fluorescent protein and luciferase for application in mouse models

目的构建绿色荧光蛋白(GFP)与萤火虫荧光素酶(FLuc)双标记的人肝癌HepG2细胞株(HepG2-GL),并应用于小鼠模型与活体生物发光成像。方法通过慢病毒感染、嘌呤霉素筛选、流式细胞分选和单克隆扩增构建HepG2-GL细胞株,并将其接种至BALB/c裸鼠皮下或静脉内,建立皮下移植瘤模型与血行性转移瘤模型,应用小动物活体成像系统示踪肿瘤。结果荧光显微镜下可观察到80%以上的HepG2-GL细胞发出绿色荧光;荧光素酶检测实验中HepG2-GL组的平均发光强度为3.2×10^(4)counts/s,远高于HepG2组,差异有统计学意义(t=65.99,P<0.05);HepG2-GL细胞接种至小鼠皮下28 d后增殖形成体积达274或690 mm^(3)的肿瘤块,接种至小鼠静脉内16 d后转移定植于小鼠肺、骨和头颈部;两类肿瘤模型小鼠在观察终点的活体生物发光信号均较接种肿瘤后当天明显增强,且信号强弱分布情况与HepG2-GL细胞在小鼠体内的空间分布密切相关。结论成功构建HepG2-GL细胞株并应用于小鼠模型,活体生物发光成像可实现对肿瘤生长与转移的良好监测。

Objective To establish a green fluorescent protein(GFP)and firefly luciferase(FLuc)double-labeled human liver cancer cell line HepG2(HepG2-GL)and apply them to mouse models for in vivo bioluminescence imaging.Methods HepG2-GL cells were constructed by lentivirus transduction,puromycin intervention,flow cytometry and monoclonal culture.Subcutaneous xenograft and hematogenous metastasis models were respectively established by subcutaneous or intravenous injection of HepG2-GL cells in BALB/c nude mice.Tumor development was monitored by IVIS spectrum in vivo imaging system.Results Green fluorescence was observed in more than 80%HepG2-GL cells under a fluorescence microscope.The average luminescence intensity in the HepG2-GL group was 3.2×10^(4)counts/s,which was much higher than that in the HepG2 group(t=65.99,P<0.05).HepG2-GL cells inoculated subcutaneously to mice proliferated to form tumor masses with a volume of 274 or 690 mm^(3)for 28 days,while HepG2-GL cells injected intravenously to mice metastasized and colonized into the lung,bone,head and neck for 16 days.At the end of the experiment,the in vivo bioluminescence signals of both tumor models were significantly enhanced compared with the day after tumor inoculation,and the distribution of signal intensity was closely related to the spatial distribution of HepG2-GL cells in mice.Conclusion The HepG2-GL cells were successfully established and applied to mouse models and in vivo bioluminescence imaging achieved good monitoring of tumor growth and metastasis.