[Establishment of a dual-fluorescence-traced lung cancer subcutaneous transplantation model in nude mice].

Objective: To establish a nude mouse model of subcutaneous lung cancer using dual fluorescence reporting genes of luciferase (Luc) and near-infrared fluorescent protein (iRFP). Methods: The Luc and iRFP expressed lentiviral vector was constructed by Gateway method. After verified by sequencing, the lentivirus particle was prepared and infected into lung cancer A549 cells. Successfully infected A549 (mA549) cells were selected by puromycin and amplified. The expression of Luc and iRFP were observed under fluorescence microscope, and the expression of c-Met protein on the cell surface was detected by immunofluorescence. Twelve female nude mice were randomly divided into 2 groups, 6 in each group. A549 and mA549 cells were inoculated subcutaneously into the right forelimb of nude mice. The growth and fluorescence expression of the tumor were observed by in vivo imaging. The tumor formation was evaluated by hematoxylin-eosin (HE) staining and immunohistochemistry. Results: The Luc and iRFP stably expressed mA549 cell line was successfully constructed. The expressions of iRFP and Luc in mA549 cells were observed under fluorescence microscope. The results of immunofluorescence showed that c-Met protein expressed in both A549 cells and mA549 cells. The growth period of mA549 xenograft in nude mice was moderate and the tumorigenesis rate was 100%. The growth trend of mA549 cells in vivo was not significantly different from that of A549 cells ( P >0.05). HE staining and immunohistochemistry results showed that the tumor issues displayed typical histopathological features of tumor. Immunohistochemistry results showed that both A549 and mA549 tumors expressed c-Met protein. Conclusion: A stable, real-time monitoring model of iRFP-Luc-A549 lung cancer cell xenograft in nude mice was successfully constructed.