Establishment and biological characteristics of human multiple myeloma cell line CZ-1.

BACKGROUND: There were only 3 multiple myeloma (MM) cell lines established in China. In this study, we succeeded in establishing a novel MM cell line and analyzed its biological characteristics. METHODS: Mononuclear cells isolated from the peripheral blood (PB) and bone marrow (BM) of a patient with advanced MM (lambda light chain type) were cultured in medium. Cell morphology was analyzed by Wright-Giemsa-staining and cytochemical staining, immunophenotyping by flow cytometry and cytogenetic analysis by chromosome RHG-banding technique. Quantitative fluorescent polymerase chain reaction (PCR) was used to detect Epstein - Barr virus (EBV) DNA. RESULTS: The established cell line could survive and proliferate in the presence of feeder cells or conditioned medium. The cells secreted lambda light chain and were negative for EBV. The Wright-Giemsa-staining showed typical plasmablast or plasma cell morphology. The cytochemical staining of the cells showed the following reactivity patterns: positive for acid phosphatase, negative for myeloperoxidase. The immunoprofile of the cells was concordant with that of MM cells: positive for CD10, CD28, CD38, CD138, CD56, CD49d, CD44, CD54 and CD58, negative for CD19, CD40, CD95, CD95L, CD34, CD2 and CD5. The cytogenetic analysis showed complex chromosome abnormality of i (1q+), 8q+, 13q+, i (17q), i (18q) and +M. There was no difference in morphology, immunophenotype and cytogenetics between cells from PB and BM. CONCLUSIONS: An MM cell line secreting lambda light chain named CZ-1 was established. The cells from both PB and BM have the same biological characteristics.

[Real-time quantitative PCR detecting minimal residual disease in multiple myeloma patients after autologous peripheral blood stem cell transplantation].

In order to explore the role of real-time PCR in detecting minimal residual disease in multiple myeloma and Waldenstrom's macroglobulinemia after autologous peripheral blood stem cell transplantation (APBSCT), real-time PCR was used to quantitate the IgH rearrangement in 8 patients with multiple myeloma (MM) and 1 case of Waldenstrom's macroglobulinemia before and after APBSCT. The results showed that the copies of IgH rearrangement pre- or post-APBSCT were 3108 +/- 1043 and 549 +/- 660 (P < 0.05) respectively. The number of IgH copies was positively correlated with the amount of plasmocytes in patient 's bone marrow and the M-protein in peripheral blood (r = 0.86, P < 0.05). Similar result was obtained in a case of relapsed Waldenstrom's macroglobulinemia. In conclusion, the quantitative analysis of IgH rearrangement by real-time PCR is a novel way to evaluate the therapeutic efficaciousness and predict the prognoses in MM patients.