The monoclonal antibody (MoAb) MM4 reacts with human multiple myeloma (MM) cell lines and bone marrow from patients with plasma cell dyscrasias but not with normal peripheral blood or bone marrow cells. Treatment with MM4 and rabbit complement (C’) was cytotoxic to the plasma cell-derived cell lines GM 1312. RPMI 8226, and ARH-77. as demonstrated by chromium release microcytotoxicity and trypan...

Recently, there has been an increasing interest in the expression pattern and biological significance of the CD45 molecule in myeloma cells. In this study, we have further defined the phenotypic pattern of CD45 expression on myeloma cells. Using a panel of myeloma cell lines, we showed that CD45 showed a remarkably heterogeneous pattern of expression. Whereas some cell lines were CD45(+) and ot...

Sphingolipid metabolism is being increasingly recognized as a key pathway in regulating cancer cell survival and proliferation. However, very little is known about its role in multiple myeloma (MM). We investigated the potential of targeting sphingosine kinase 2 (SK2) for the treatment of MM. We found that SK2 was overexpressed in MM cell lines and in primary human bone marrow (BM) CD1381 myelo...

PURPOSE Despite significant therapeutic progress in multiple myeloma, drug resistance is uniformly inevitable and new treatments are needed. Our aim was to identify novel, efficacious small-molecule combinations for use in drug resistant multiple myeloma. EXPERIMENTAL DESIGN A panel of 116 small molecule inhibitors was used to screen resistant myeloma cell lines for potential therapeutic targ...

Because interleukin-10 (IL-10) is a potent differentiation factor of human B cells into mature plasma cells, we investigated its effect on human malignant plasma cells. IL-10 did not induce any differentiation and increase in Ig synthesis in four human IL-6-dependent malignant plasma cell lines. However, it stimulated the proliferation of two of four cytokine-dependent cell lines in the absence...

Chromosome 8q24 rearrangements are occasionally found in multiple myeloma and are associated with tumor progression. The 8q24 rearrangements were detected by FISH in 12 of 54 patients with multiple myeloma (22.2%) and in 8 of 11 multiple myeloma cell lines (72.7%). The breakpoints of 8q24 in 10 patients with multiple myeloma and in all multiple myeloma cell lines were assigned to a 360 kb segme...

In the search for a more effective adjuvant therapy to treat multiple myeloma (MM), we investigated the effects of the traditional Chinese herbal medicines Huang-Lian-Jie-Du-Tang (HLJDT), Gui-Zhi-Fu-Ling-Wan (GZFLW), and Huang-Lian-Tang (HLT) on the proliferation and apoptosis of myeloma cells. HLJDT inhibited the proliferation of myeloma cell lines and the survival of primary myeloma cells, es...

DEPTOR is a 48 kDa protein that binds to mTOR and inhibits this kinase in TORC1 and TORC2 complexes. Overexpression of DEPTOR specifically occurs in a model of multiple myeloma. Its silencing in multiple myeloma cells is sufficient to induce cytotoxicity, suggesting that DEPTOR is a potential therapeutic target. mTORC1 paralysis protects multiple myeloma cells against DEPTOR silencing, implicat...

CD28 expression was thoroughly investigated on plasma cells of monoclonal gammopathy of undetermined significance, multiple myeloma (MM), and human myeloma cell lines. CD28+ plasma cells were detected in 19% of 31 monoclonal gammopathy of undetermined significance, 41% of 116 MM, and 100% of 13 human myeloma cell lines. CD28+ myeloma cells were detected in 21 of 79 (26%) MM cases at diagnosis, ...

Recent phenotypic analysis of plasma cells showed that normal plasma cells do express the B-cell lineage-specific molecule CD19, but their malignant counterpart (myeloma cells) are CD19-. To clarify the meaning of loss of CD19 antigen on myeloma cells, we first compared the expression of CD19 and Pax-5 genes among B cells, normal plasma cells, myeloma cell lines, and primary myeloma cells, beca...