[Establishment and characteristics of orthotopically transplanted model of human primary malignant small intestinal lymphoma in nude mice].

OBJECTIVE:To establish orthotopically transplanted model of human malignant small intestinal lymphoma in nude mice and analyze their biologic characteristics. METHODS:Small intestinal lymphoma tissues from 5 patients were transplanted into intestinal mucosa of nude mice. Tumorgenecity, invasion and metastasis of the transplanted tumors were observed by morphological analyses (light microscopy, electron microscopy and immunohistochemistry), karyotyping and DNA quantitative assay. RESULTS:Tumor tissues from 3 lymphoma patients were successfully transplanted. According to the World Health Organization classification, the three models were classified into non-Hodgkin's lymphoma (B cell) of human small intestine (HSIL-1), high metastasis of non-Hodgkin's lymphoma (B cell) of human small intestine (HSIL-2) and non-Hodgkin's lymphoma (T cell) of human small intestine (HSIL-3), respectively. Immunohistochemistry showed that CD19, CD20, CD22, CD40, CD45 and CD72 were positive in HSIL-1 and HSIL-2, whereas CD3, CD7 and CD45RO were positive in HSIL-3. The karyotypes of the transplanted tumors were all hypotriploid with modal numbers from 55 to 69 and the DNA index (DI) was 1.46 approximately 1.71. The three models had been passaged for 32, 27 and 21 generations respectively in 433 nude mice. The growth rate, resuscitation rate of the liquid nitrogen preserved tumor cells and spontaneous metastasis rate upon transplantation were all 100%. We observed an invasive growth of the transplanted tumors in small intestine, which resulted in disrupting of the intestinal wall, hematogenous metastasis, lymph node metastasis and seeding metastasis. The features of the transplanted tumors were similar to the original tumors in histopathology, ultrastructure, DNA content and karyotype. CONCLUSION:Three strains of orthotopically transplanted model of human primary malignant small intestinal lymphoma in nude mice were successfully developed. The result of research will provide ideal animal models for further studies on mechanism of tumorigenesis, invasion and metastasis of malignant small intestinal lymphoma and experimental therapy.