Background The primary reasons for local recurrence and therapeutic failure in the treatment of malignant gliomas are the invasion and interactions of tumor cells with surrounding normal brain cells. However, these tu...Background The primary reasons for local recurrence and therapeutic failure in the treatment of malignant gliomas are the invasion and interactions of tumor cells with surrounding normal brain cells. However, these tumor cells are hard to be visualized directly in histopathological preparations, or in experimental glioma models. Therefore, we developed an experimental human dual-color in vivo glioma model, which made tracking solitary invasive glioma cells possible, for the purpose of visualizing the interactions between red fluorescence labeled human glioma cells and host brain cells. This may offer references for further studying the roles of tumor microenvironment during glioma tissue remodeling. Methods Transgenic female C57BL/6 mice expressing enhanced green fluorescent protein （EGFP） were crossed with male Balb/c nude mice. Then sib mating was allowed to occur continuously in order to establish an inbred nude mice strain with 50% of their offspring that are EGFP positive. Human glioma cell lines U87-MG and SU3 were transfected with red fluorescent protein （RFP） gene, and a rat C6 glioma cell line was stained directly with CM-Dil, to establish three glioma cell lines emitting red fluorescence （SU3-RFP, U87-RFP, and C6-CM-Dil）. Red fluorescence tumor cells were inoculated via intra-cerebral injection into caudate nucleus of the EGFP nude mice. Tumor-bearing mice were sacrificed when their clinical symptoms appeared, and the whole brain was harvested and snap frozen for further analysis. Confocal laser scanning microscopy was performed to monitor the mutual interactions between tumor cells and host brain cells. Results Almost all the essential tissues of the established EGFP athymic Balb/c nude mice, except hair and erythrocytes, fluoresced green under excitation using a blue light-emitting flashlight with a central peak of 470 nm, approximately 50% of the offsprings were nu/nu EGFP＋. SU3-RFP, U87-RFP, and C6-CM-Dil almost 100% expressed red fluorescence under the fluorescence microscope. Under fluorescence microscopic view, RFP＋ cells were observed growing wherever they arrived at, locating in the brain parenchyma, ventricles, and para-vascular region. The interactions between the transplanted tumor cells and host adjacent cells could be classified into three types： （1） interweaving; （2） mergence; and （3） fusion. Interweaving was observed in the early stage of tumor remodeling, in which both transplantable tumor cells and host cells were observed scattered in the tumor invading and spreading area without organic connections. Mergence was defined as mutual interactions between tumor cells and host stroma during tumorigenesis. Direct cell fusion between transplantable tumor cells and host cells could be observed occasionally. Conclusions This study showed that self-established EGFP athymic nude mice offered the possibility of visualizing tumorigenesis of human xenograft tumor, and the dual-color xenograft glioma model was of considerable utility in studying the process of tumor remodeling. Based on this platform, mutual interactions between glioma cells and host tissues could be observed directly to further elucidate the development of tumor microenvironment.展开更多
目的建立一个能稳定表达增强型绿色荧光蛋白(enhanced green fluorecence protein,EGFP)的裸小鼠近交新品系,供包括人脑胶质瘤在内的所有人类肿瘤移植实验用。方法将雌性C57BL/6-Tg(CAG-EGFP)转基因小鼠和雄性Foxn1nu裸小鼠,按同源导入...目的建立一个能稳定表达增强型绿色荧光蛋白(enhanced green fluorecence protein,EGFP)的裸小鼠近交新品系,供包括人脑胶质瘤在内的所有人类肿瘤移植实验用。方法将雌性C57BL/6-Tg(CAG-EGFP)转基因小鼠和雄性Foxn1nu裸小鼠,按同源导入方法进行杂交和回交,用荧光手电筒和匹配的眼镜、多功能活体成像仪、荧光显微镜对是否表达EGFP进行鉴别,传至F10后进行遗传学检测。结果所建品系命名为Foxn1nu.B6-CAGEGFP/SU(Soochow University),14个遗传生化位点中13个表型与BALB/c(Foxn1nu)吻合,唯Pep3(肽酶-3)的电泳为b型,而标准的BALB/c近交系为a型;外周血淋巴细胞占全部有核细胞15%,T淋巴细胞仅占0.3%,与亲本的Foxn1nu一致。结论成功地建立了一个既与亲本C57BL/6-Tg N(CAG-EGFP)-样稳定表达EGFP,又与Foxn1nu裸小鼠(BALB/c背景)一样具有T细胞缺乏的荧光裸小鼠新品系-Foxn1nu.B6-CAG-EGFP|SU,Pep3为b型是有别于Foxn1nu裸小鼠的生化遗传标记位点。展开更多
基金This study was supported by grants from the National Natural Science Foundation of China （No. 81071766, No. 81101909, and No. 81172400）, the National Basic Research Program of China （＂973＂ Program, No. 2010CB529403）, and the Natural Science Foundation of Jiangsu, China （No. BK2010227）.
文摘Background The primary reasons for local recurrence and therapeutic failure in the treatment of malignant gliomas are the invasion and interactions of tumor cells with surrounding normal brain cells. However, these tumor cells are hard to be visualized directly in histopathological preparations, or in experimental glioma models. Therefore, we developed an experimental human dual-color in vivo glioma model, which made tracking solitary invasive glioma cells possible, for the purpose of visualizing the interactions between red fluorescence labeled human glioma cells and host brain cells. This may offer references for further studying the roles of tumor microenvironment during glioma tissue remodeling. Methods Transgenic female C57BL/6 mice expressing enhanced green fluorescent protein （EGFP） were crossed with male Balb/c nude mice. Then sib mating was allowed to occur continuously in order to establish an inbred nude mice strain with 50% of their offspring that are EGFP positive. Human glioma cell lines U87-MG and SU3 were transfected with red fluorescent protein （RFP） gene, and a rat C6 glioma cell line was stained directly with CM-Dil, to establish three glioma cell lines emitting red fluorescence （SU3-RFP, U87-RFP, and C6-CM-Dil）. Red fluorescence tumor cells were inoculated via intra-cerebral injection into caudate nucleus of the EGFP nude mice. Tumor-bearing mice were sacrificed when their clinical symptoms appeared, and the whole brain was harvested and snap frozen for further analysis. Confocal laser scanning microscopy was performed to monitor the mutual interactions between tumor cells and host brain cells. Results Almost all the essential tissues of the established EGFP athymic Balb/c nude mice, except hair and erythrocytes, fluoresced green under excitation using a blue light-emitting flashlight with a central peak of 470 nm, approximately 50% of the offsprings were nu/nu EGFP＋. SU3-RFP, U87-RFP, and C6-CM-Dil almost 100% expressed red fluorescence under the fluorescence microscope. Under fluorescence microscopic view, RFP＋ cells were observed growing wherever they arrived at, locating in the brain parenchyma, ventricles, and para-vascular region. The interactions between the transplanted tumor cells and host adjacent cells could be classified into three types： （1） interweaving; （2） mergence; and （3） fusion. Interweaving was observed in the early stage of tumor remodeling, in which both transplantable tumor cells and host cells were observed scattered in the tumor invading and spreading area without organic connections. Mergence was defined as mutual interactions between tumor cells and host stroma during tumorigenesis. Direct cell fusion between transplantable tumor cells and host cells could be observed occasionally. Conclusions This study showed that self-established EGFP athymic nude mice offered the possibility of visualizing tumorigenesis of human xenograft tumor, and the dual-color xenograft glioma model was of considerable utility in studying the process of tumor remodeling. Based on this platform, mutual interactions between glioma cells and host tissues could be observed directly to further elucidate the development of tumor microenvironment.
