Malignant hematopoietic cell lines: in vitro models for the study of multiple myeloma and plasma cell leukemia.

Multiple myeloma (MM) is a neoplasm of a terminally differentiated B-cell. The disease is progressive and always lethal characterized by the slow proliferation of malignant plasma cells in the bone marrow. Much of our current understanding of the biology of MM has been obtained by studying MM-derived cell lines. Human myeloma cell lines were shown to be suitable model systems for use in various fields of the biological sciences. However, it has proved very difficult to establish cell lines from plasma cell dyscrasias. Most reported MM cell lines have been derived from patients with advanced disease and from extramedullary sites. Nevertheless, within the last 20 years more than 100 cell lines have been established. A significant portion of this panel is partially or well characterized with regard to their cell culture, clinical, immunophenotypic, cytogenetic and functional features. Distinct immunoprofiles could be assigned to MM cell lines. All MM cell lines display chromosomal aberrations; in more than 80% of the cell lines analyzed, chromosome 14 band q32 (immunoglobulin heavy chain locus) is affected; the various types of 14q+ chromosomes showed different distributions among the MM cell lines. A large percentage of MM cell lines is constitutively interleukin-6-dependent or responsive to various cytokines. It is important to realize that not every cell line established from a patient with myeloma is a neoplastic cell line. So-called 'myeloma cell lines' have been previously reported and are still widely used which are in reality Epstein-Barr virus (EBV)-positive B-lymphoblastoid cell lines. The presence of the EBV-genome in residual normal B-cells provides them with a selective growth advantage after explantation. In summary, a significant number of authentic and well-characterized MM cell lines has been established and described. The availability of these bona fide MM cell lines is of great importance for the study of the biology, etiology and treatment of the disease.