Abstract: 【Abstract】 Objective To establish SKH-1 mouse models of subcutaneously transplanted B16F10 melanoma and of lung-metastasized B16F10 melanoma. Methods Seven SKH-1 mice and seven C57BL/6 mice were subcutaneously inoculated with 5 × 106 B16F10 cells on the back, and the survival duration of mice was observed and recorded. The tumor volume was measured by using a precision vernier caliper every 3 days. Mice were considered as ethically dead when the tumor length was more than 15 mm, or when cachexia or ulceration occurred. In addition, 5 SKH-1 mice were injected with 5 × 106 B16F10 cells via the tail vein, and the activity, nutritional status and survival duration were observed. The mice were sacrificed after the observation, and the lungs were weighed after dissection. Histopathological examination was performed on the lungs of all mice. All the experiments were repeated 3 times. Results On day 6 after the subcutaneous inoculation, black spots appeared at the skin inoculation site in the SKH-1 mice, and gradually developed into round black nodules, then progressed into ulcerative and hemorrhagic tumors until the death of mice, and the time to ethical death ranged from 20 to 33 days. In the C57BL/6 mice, small black nodules measuring 2 - 3 mm in length appeared at the skin inoculation site on day 4 after the subcutaneous inoculation, and the time to ethical death ranged from 12 to 18 days. The survival duration of SKH-1 mice was 26.57 ± 4.03, 27.86 ± 4.53, and 27.43 ± 5.32 days in the 3 times of experiments respectively, and there was no significant difference （F = 0.14, P = 0.87）; on day 27 after the subcutaneous inoculation, the tumor volume was 1 367.9 ± 150.2, 1 452.0 ± 50.1, and 1 490.3 ± 69.0 mm3 in the 3 times of experiments respectively, and there was also no significant difference （F = 0.92, P = 0.46）. SKH-1 mice had shown decreased activity and anorexia since day 25 after tail vein injections of B16F10 cells, and dullness, emaciation, ascites and death had been observed since day 31, and the time to ethical death ranged from 31 to 40 days; multiple black nodules were observed in the lung after dissection, and the survival duration was 34.2 ± 2.58, 36.4 ± 2.60, and 34.8 ± 2.38 days in the 3 times of experiments respectively, which did not differ among the 3 times of experiments （F = 1.01, P = 0.39）; there was also no significant difference in the lung weight among the 3 times of experiments （156.1 ± 18.5, 164.0 ± 19.6, and 172.0 ± 17.2 mg, respectively, F = 3.18, P = 0.72）. All the mice developed tumors, and histopathological examinations of subcutaneous tumor masses and lung tissues confirmed the diagnosis of melanoma. Conclusion In this experiment, the SKH-1 mouse models of subcutaneously transplanted B16F10 melanoma and of lung-metastasized B16F10 melanoma were successfully established, which showed high tumor formation rates and favorable stability in tumor formation.

Key words: Melanoma, Models, animal, Mice, hairless, Mice, inbred C57BL, SKH-1 mice, Tumor model