DISSEMINATED GROWTH OF MURINE PLASMACYTOMA - SIMILARITIES TO MULTIPLE-MYELOMA

Murine plasma cell tumors share a number of common features with human multiple myeloma, suggesting their possible use as a model for this d isease. However, one major difference between the two is the peritonea l localization of murine tumors as opposed to bone marrow residence of malignant plasma cells in early stages of multiple myeloma. We have t hus examined the ability of murine plasmacytoma to produce disseminate d growth similar to that seen in myeloma or other lymphoid neoplasias, Of four murine cell lines evaluated, all were demonstrated to effect highly metastatic disease involving multiple organs, although variatio n was observed between lines, A temporal analysis was accordingly perf ormed with the S107 line to assess the pattern of cellular localizatio n, Both light microscopy and PCR analysis revealed that engraftment of plasma cells occurs first in the bone marrow, followed by disseminati on to other sites including the spleen, lung, and liver, Cells passage d in vivo through the bone marrow display an entirely different metast atic pattern with no homing preference to bone marrow or any other org an, suggesting the occurrence of a phenotypic change, Microscopic oste olytic lesions were observed adjacent to plasma cell tumor masses in t he bone marrow, indicating early stages of bone disease, These finding s demonstrate previously unrecognized similarities between the murine and human diseases and suggest the use of this in vivo model for exper imental approaches to the treatment of human disease.