Abstract: Objective To establish a human osteosarcoma cell line with high lung metastasis ability and provide a research model for explore the mechanism of lung metastasis of osteosarcoma. Methods The human osteosarcoma 143B cells labeled with GFP and luciferase were resuspended into a MEM medium and mixed with Matrigel gel (1∶1) to make a cell suspension (1×10⁷/mL) , and 10 μL of the suspension was injected into the left tibia of 4-week-old BALB/c nude mice to establish a model of lung metastasis by in situ injection into the tibia (n=6) . The lung metastasis nodules were collected to make a single-cell suspension, cultured adherently in a complete medium, and amplified with neomycin (G418) resistance screening, then inoculated into the tibia of nude mice again. The cells obtained after circulating twice in vivo by the same method were named 143B-HLM. The cell migration was detected by the vitro real-time cell migration assay, the expression of key molecular markers of cell migration and infiltration was detected by RT-qPCR and Western blot, and lung tumor nodule formation in lung metastatic tumor model was observed. Results Compared with parental human osteosarcoma 143B cells, 143B-HLM cells had higher migratory capacity in vitro; the protein expression of Vimentin and Slug, and the mRNA expression levels of Vimentin, Slug, Snail, and Survivin were increased (all P<0.05) . Compared with nude mice injected with 143B cells, the tumor-bearing model in which 143B-HLM cells were injected in situ into the tibia of nude mice, the tumor volume in situ was decreased (P<0.05), the fluorescence intensity of lung tumor metastasis was significantly increased, and the number of lung metastasis was also increased (P<0.01). Conclusions A stable osteosarcoma cell line 143B-HLM with high lung metastatic capacity was successfully established through in vivo circulation screening and isolation of osteosarcoma metastatic cells.

Key words: Osteosarcoma cell line, 143B-HLM, High lung metastasis cell line