Organ-specific growth of a murine lymphoma of spontaneous origin in nude mice.

The MOC-25 tumour arose spontaneously in a female nude mouse and was established as a continuous line intraperitoneally in nude mice, where it reproduces the topological features of its origin, growing preferentially in the uterus, ovaries and liver. Karyotype analysis showed that MOC-25 cells are hyperdiploid. Tumorigenicity and malignant behaviour were studied by transplanting tumour cells into different sites in nude mice. The comparison of tumour take after i.p. and s.c. injections of scaled concentrations of MOC-25 cell suspension showed preferential growth in the peritoneum. Regardless of the route of implantation (s.c., i.v., i.p.), this tumour rapidly and preferentially disseminated to the liver, uterus, ovaries, spleen and bone marrow. No significant differences in tumour growth and metastatic behaviour were observed when MOC-25 was injected in ovariectomized nude mice or in male nude mice. Morphology studies using light and electron microscopy, immunophenotyping and molecular analysis indicated a B-lymphoid origin of the MOC-25 tumour.