Establishment of lung metastasis model of human primary malignant melanoma in the small intestine in nude mice.

Objective To provide an ideal animal model for exploring the pathogenesis and experimental treatment of malignant melanoma in the small intestine.Methods Fresh tissue of lung metastatic lesions from patients with malignant melanoma of the smallintestine were transplanted into mucosa of the small intestine in nude mice.After 4 times of screening.the tissue of the lung metastatic lesions from the nude mice were transplanted into the small intestine of additionat nude mice.Tumorgenecity and metastasis of transplanted tumors were observed,and were analyzed by morphology,karyotype and flow cytometry.Results A lung metastatic model of human primary malignant melanoma of the small intestine in nude mice was successfully constructed and named HSIM-0601.Massive melanin granules and melanin complex were seen in cytoplasm of tumor cells.Immunohistochemical straining of S-100 and HMB-45 were positive.The number of chromosome was between 57 and 59.DNA index was 1.49.HSIM-0601 was passed for 26 generations.A total of 173 nude mice were used for tumor transplantation.The growth rate of the transplanted tumors and resuscitation rate of liquid nitrogen cryopreservation were both 100%.In HSIM-0601.lung metastasis rate was 100%(173/173)and lymph node metastasis rate was 61.3%(106/173).Conclusions The HSIM-0601 successfully mimics the natural clinicopathologic course of patients with primary small intestinal melanoma,and provides an ideal animal model for research on pathogenesis,metastasis and experimentM therapy of malignant lymphoma in the small intestine. Key words: Small intestinal neoplasmas;  Malignant melanoma; Lung metastasis;  Nude mice