Establishment of double fluorescent animal models by orthotopic transplantation of human glioma cells into nude mice

Objective To establish the double fluorescent animal models of orthotopic transplantation of human glioma cells into nude mice and provide dynamic observation of occurrence and development of gliomas. Methods Human U87 cells were transfected with enhanced red fluorescent protein(ERFP)and then inoculated into the right caudate nucleus of nude mice with enhanced green fluorescent protein(EGFP). Dynamic observation of tumor growth was carried out by in vivo imaging. HE staining was performed on the transplanted tumor tissues 4 weeks after inoculation; the relation of tumor cells and host matrix cells was observed under fluorescence microscope. Results Green fluorescence could be seen in the whole body tissues and organs of nude mice expressed EGFP by in vivo imaging. Red fluorescence could be noted at the graft sites at one week after ERFP-U87 inoculation, and the red fluorescence enhanced as time prolonged. HE staining indicated that the tumor cells in the transplanted tumor tissues were deep dyed with big nucleus; these cells with multinuclear were at division phase. Fluorescence microscope showed that tumor cells and host matrix cells enjoyed red fluorescence and green fluorescence, respectively. Boundary between tumor tissues and mice brain tissues was not clear, tumorigenesis vessels could be seen; normal endothelial cells formed the vessels and some tube walls had tumor cells. Conclusion In these animal models, tumor growth can be dynamically observed, thus, they may serve as ideal models in basic research on gliomas. Key words: Glioma; Orthotopic transplantation; In vivo imaging; Green fluorescent protein; Red fluorescent protein