OBJECTIVETo construct a mouse model of highly metastatic gastric lymphoma with orthotopic transplantation of human primary gastric lymphoma specimen.

METHODSA fresh surgical specimen of primary gastric lymphoma was obtained intraoperatively and implanted into the submucosa of stomach in nude mice. Tumor formation, invasion, metastasis, morphological characteristics under light microscopy and electron microscopy, immunohistochemistry,and the karyotype of orthotopically transplanted tumor cells were studied.

RESULTSAn orthotopic highly metastatic model of human primary gastric lymphoma in nude mice(HGBL-0305) was successfully established. Histopathology of transplanted tumors showed primary gastric diffuse large B cell lymphoma. CD19, CD20, CD22 and CD79alpha were positive, while CD3 and CD7 were negative. The number of chromosome ranged from 56 to 69. DNA index(DI) was 1.47+/-0.12(i.e. heteroploid). Until now, HGBL-0305 model has been maintained for 45 generations by orthotopic passage for almost 4 years in nude mice. A total of 156 nude mice were used for transplantation. The growth rate and resuscitation rate of liquid nitrogen cryopreservation of transplanted tumor cells were both 100%. The autonomic growth of the transplanted tumor cells invaded and destructed all the layers of the nude mice stomach. The metastasis rates of liver, spleen, lymph node, and peritoneal seeding were 69.5%, 55.6%, 45.7%, and 30.5%, respectively.

CONCLUSIONSAn orthotopic highly metastatic model of human primary gastric lymphoma in nude mice is successfully established. HGBL-0305 model may simulate the natural course of primary gastric lymphoma in human and provides an ideal animal model for studies on pathogenesis, metastasis biology and anti-metastatic therapies of primary gastric lymphoma.