OBJECTIVETo establish a nude mouse model of orthotopically transplanted human primary malignant lymphoma of the liver, and to serve researches on pathogenesis and experimental treatment of this disease.

METHODSSmall pieces of lymphoma tissues freshly taken from patients with primary lymphoma of the liver were orthotopically transplanted into the liver parenchyma in nude mice. Tumorgenicity, invasion, metastasis, and morphological characteristics were examined by light and electron microscopy and immunohistochemistry. AFP, HBsAg and LDH were assayed by serological test. Karyotype analysis and DNA content of orthotopically transplanted tumors were also performed.

RESULTSA nude mouse model of orthotopically transplanted human primary malignant lymphoma of the liver was successfully established and named HLBL-0102. The tumor was confirmed as primary lymphoma of the liver (non-Hodgkin's lymphoma, B cell) by histopathology. Immunohistochemistry showed positive expression of CD19, CD20, CD45 and CD79a, but negative of CD3 and CD7. Serological test indicated that AFP was negative, HBsAg positive and the concentration of LDH was 1267.5 U/L. The number of chromosomes was between 55 and 59. DNA index (DI) was 1.57 approximately 1.61 (i.e. heteroploid). So far, the strain HLBL-0102 has grown for 3 years and been passaged for 37 generations in nude mice. Totally 283 nude mice were used for transplantation and the successful rate was 100%. Both the growth rate and resuscitation rate of liquid nitrogen cryo-preserved transplanted tumors were 100%. The transplanted tumors grew intensely and invasively in the liver of nude mice and damaged adjacent liver tissues, bile ducts and portal vein areas. No involvement of other tissues and organs and distal lymph nodes was observed.

CONCLUSIONTo our knowledge it is the first report of successfully established nude mouse model of orthotopically transplanted human primary malignant lymphoma of the liver. The HLBL-0102 model simulate very well the natural process of human primary lymphoma of the liver and provides an ideal animal model for researches on the biology and therapies of this malignancy.