裸鼠原位和异位脑肿瘤生物发光信号成像实验研究

目的应用生物发光成像技术,非侵入性地连续检测活体裸鼠原位和异位脑肿瘤发展演进过程。方法用SMPU-R-MND-luc载体转染人脑肿瘤U87MG细胞系,形成具有高荧光素酶活性的细胞克隆。在裸鼠脑内和胁腰部皮下植入持续表达荧光素酶的肿瘤细胞,建立原位和异位脑肿瘤模型,用影像学资料显示肿瘤部位。用光子发射定量分析动态监测肿瘤生长情况。结果成功地建立了表达荧光素酶活性的原位和异位脑肿瘤动物模型。采集反映肿瘤生长的生物发光信号,肿瘤细胞植入后不同时间点的发光信号值呈显著正相关,而且原位和异位脑肿瘤间存在明显差异。但生物发光脑肿瘤生物发光信号值在第4 d和第14 d时无显著差异。结论体内生物发光成像可以非侵入性地动态检测活体内脑肿瘤演进过程,为研究肿瘤发展机制及最佳治疗策略的选择提供了新的手段和工具。

Experiment study on bioluminescent signal in orthotopic and heterotopic brain tumors in nude mice

Objective To investigate the bioluminescent signal in orthotopic and heterotopic brain tumors in nude mice for noninvasive monitoring on progression of brain tumor in vivo.Methods The human brain tumor cell line U87MG cells were transduced by using the SMPU-R-MND-luc vector then a clone with high luciferase activity was cloned and used for in vivo experiments.Tumor cells were implanted into the brains and flanks of the animals,and whole body images revealing tumor location were obtained.Tumor burden was monitored over time by quantity of photon emission.Results Orthotopic brain tumor and heterotopic flank tumor models were established by implanting constitutively expressing luciferase tumor cells in the brains and flanks of the animals.The magnitude of(bioluminescence) from firefly luciferase measured in vivo correlated with the time after injection of luciferin,indicating that the time of post-injection signal quantification was of special importance.Furthermore,the time courses in the heterotopic and orthotopic tumors were observed significantly different.However,kinetic studies performed on the 4 th and 14 th day post-cell implantation revealed no significant differences in orthotopic tumors.Conclusion This model system with in vivo bioluminescence imaging is an excellent experimental animal model in research for noninvasive monitoring on progression of brain tumor in vivo.