Requirement of soluble factors produced by bone marrow stromal cells on the growth of novel established human myeloma cell line.

The growth of myeloma cells is believed to be mediated by functional interactions between tumor cells and the marrow environment involving the action of several cytokines. We report on the establishment and characterization of a new human myeloma cell line (TAB1) that can be long-term maintained in the presence of conditioned medium of bone marrow stromal cells (BMCM) and a BMCM independent variant, C2-2. Both cell lines have plasma cell morphology and express plasma cell antigens (CD38, PCA-1 and immunoglobulin kappa light chain). In the absence of BMCM, TAB1 cells undergoing apoptosis were observed. Among the adherent molecules tested, these cells expressed VLA-4, ICAM-1 and H-CAM, but not VLA-5, suggesting that these were mostly immature plasmacytes. Introduction with exogenous IL-6 and/or GM-CSF, which were detected in BMCM, partially supported the proliferation of TAB1 cells. Treatment with anti-IL-6 antibody partially inhibited the proliferation of TAB1 cells cultured with BMCM. These findings strongly suggest that TAB1 required at least two or more factors on their growth in vitro; IL-6 was one of the factors necessary for cell growth. Further studies are required to clarify the precise molecules which support TAB1 cell growth in combination with IL-6, however, TAB1 and its variant C2-2 cells may offer an attractive model to unravel novel molecular mechanisms involved in bone marrow stroma-dependent growth of myeloma cells.

[Multiple myeloma of the IgD-lambda type invading CNS].

A 52-year-old woman was admitted to the gynecological department of our hospital on July 29, 2002 because of a right lower abdominal mass. She has been suffering from pain in the right leg and inguinal area for a month before coming to the hospital. She was found to have pancytopenia and high serum levels of LDH and IgD. A bone marrow examination showed 63.8% of plasma cells and serum immunoelectrophoresis showed M-protein of the IgD-lambda type. She was diagnosed as having multiple myeloma and transferred to our department. VAD therapy was started from August 22. Although the plasma cells in the bone marrow almost disappeared, the right lower abdominal mass remained and a new mass appeared on the right frontal chest wall after two courses of the treatment. Combination chemotherapy with vincristine, ranimustine, melphalan, and dexamethasone (ROAD) was started on November 1. This was followed with thalidomide and radiation therapy of the right inguinal region was added. On December 16th, she suddenly experienced speech disturbance, nausea and the disturbance of consciousness. Examination of her cerebrospinal fluid showed 368/microl mononuclear cells with 93% plasma cells. The plasma cells disappeared after the 6th intrathecal injection with MTX and prednisolone and the chemotherapy was resumed. One month later, CNS relapse was apparent followed by generalized spread of the tumor mass, and she died on March 17, 2003.

Treatment of high-risk peripheral T-cell lymphomas other than anaplastic large-cell lymphoma with a dose-intensified CHOP regimen followed by high-dose chemotherapy. A single institution study.

We investigated the efficacy of a dose-intensified double-CHOP regimen followed by high-dose chemotherapy with or without peripheral blood stem cell transplantation (PBSCT) in 11 patients with four types of peripheral T-cell lymphoma (PTCL). Three of the 4 patients with unspecified PTCL (PTCLu) achieved complete response (CR); 1 patient relapsed and 1 died of secondary leukemia after consolidation therapy. All angioimmunoblastic T-cell lymphoma (AILT) and subcutaneous panniculitis-like T-cell lymphoma (SPTCL) patients achieved CR; 5 of 6 have remained disease free for more than 3 years. The patient with hepatosplenic lymphoma did not achieve CR even after PBSCT and underwent allogenic bone marrow transplantation (allo-BMT). Thus, our regimen appears to be effective for high-risk AILT and SPTCL. However, allo-BMT should be considered for high-risk of PTCLu and hepatosplenic T-cell lymphoma.