Figure 2. Overexpression of homozygous D104N (p.104NN) endostatin does not significantly inhibit osteosarcoma (OS) lung metastasis.

(a) OS pulmonary metastasis was significantly inhibited by wild type endostatin but not by p.104NN endostatin (n = 8 mice). Mice were inoculated subcutaneously with LM8 cells that had been transfected with the indicated plasmid. Two weeks after inoculation, the mice were anesthetized, and the primary tumors were removed surgically. The lungs were removed 2 weeks after surgery, and the macroscopic pulmonary metastasis foci were counted. (b) Mice were inoculated subcutaneously with LM8 cells that had been transfected with the indicated plasmid. After the tumors reached 532 mm³ (±52), the mice were anesthetized, and the primary tumors were removed surgically. The lungs were removed 2 weeks after surgery, and the macroscopic pulmonary metastasis foci were counted. (c) Treatment with endostatin significantly inhibited OS lung metastasis in the p.104NN endostatin expressing LM8 xenograft model. Mice were inoculated subcutaneously with LM8 cells that had been transfected with the p.104NN endostatin plasmid. Two weeks after inoculation, the mice were anesthetized, and the primary tumors were removed surgically. Then, the mice were treated with endostatin (5 mg/kg, every 2 days) or PBS. The lungs were removed 2 weeks after surgery, and the macroscopic pulmonary metastasis foci were counted.