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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cultured human myeloma cells (ARH-77, RPMI-8226 and U-266), like leukaemic B lymphoid cells, consistently exerted a strong stimulating capacity on allogeneic lymphocytes in the 'one-way' mixed lymphocyte reaction. An optimal stimulation was seen when a 1:1 ratio or 1:2 ratio of responding cell:stimulating cells of each cell line was utilized. The stimulating capacity of ARH-77 or RPMI-8226 cells was significantly diminished when a 1:4 ratio of responding cells:stimulating cells was utilized. Fresh bone marrow cells containing more than 80% plasma cells from a patient with multiple myeloma, on the other hand, failed to exert the stimulating capacity on two occasions. The striking difference between cultured myeloma cells and fresh plasma cells is that the Ia-like antigen is present on cultured myeloma cells, and this antigen is absent on fresh plasma cells. The relationship between the Ia-like antigen and the stimulating capacity in 'one-way' mixed lymphocyte reaction is discussed.
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PMID:Human myeloma cells and their strong stimulating capacity in 'one-way' mixed lymphocyte reaction: a comparative study with leukaemic B lymphoid cells. 15 62

A human plasma cell line designated ARH-77 has been established and propagated in culture for the past 2 years. The cells exhibited morphological characteristics of plasma cells under light and electron microscopic examination. An average of 40% cells are positive for immunoglobulin G by direct immunofluorescence, while an immunoglobulin G-specific radioimmunoassay reveals the production of 1.21 X 10(4) ng/10(6) plasma cells. The karyotype is aneuploid with a a modal chromosome number of 45 to 46 and no marker chromosome. Growth kinetics characteristics are: doubling time, 110.4 hr; generation time, 56.4 hr; G1 + G2-phase transit time, 45.5 hr; S-phase transit time, 10.9 hr; growth fraction, 74%; mitotic index, 1.5%; labeling index, 14.3%; and cell loss, 31.0%. Some of the growth kinetics characteristics were markedly similar to the properties displayed in vivo by plasma cells of patients with multiple myeloma and suggest that the cell line might be a useful in vitro model for the study of human myeloma.
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PMID:Establishment of a human plasma cell line in vitro. 56 14

The role of interleukin 6 (IL-6) in the growth of five multiple myeloma-derived cell lines was characterized. The U266 and RPMI 8226 cell lines demonstrated increased DNA synthesis when cultured with exogenous IL-6, expressed IL-6 cell surface receptors (IL-6Rs) and expressed mRNA for IL-6R. However, these cells did not secrete detectable IL-6 protein, and a neutralizing antibody to IL-6 did not inhibit their growth. Three other myeloma-derived cell lines ARH-77, IM-9 and HS-Sultan did not respond to exogenous IL-6, secrete IL-6 or express cell surface IL-6Rs. The IL-6 responsive cell lines bore late B-cell surface antigens (Ags), CD38 and PCA-1, whereas those lines which were non-IL-6 responsive strongly expressed B1 (CD20) and B4 (CD19) Ags, representing earlier stages in B-cell differentiation. Finally, the two IL-6 responsive cell lines did not express Epstein-Barr virus (EBV) proteins; in contrast, EBV encoded proteins typically expressed during latency could be detected in the three non-IL-6 responsive lines, confirming infection with virus. These studies clarify the heterogeneity observed in the myeloma cell line phenotype and biology and suggest that the U266 and RPMI 8226 cell lines, which express IL-6 cell surface receptors and are IL-6 responsive, may be useful for further study of IL-6 signal transduction in and related IL-6 mediated growth of myeloma in vivo. In contrast, those cell lines which are IL-6-independent provide a model for further study of EBV transformation and IL-6-dependent growth mechanisms in malignancy.
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PMID:Role of interleukin 6 in the growth of myeloma-derived cell lines. 140 8

In multiple myeloma, malignant plasma cells are localized in marrow and rarely circulate in peripheral blood. To investigate the role of adhesion proteins in this process, we determined the expression and function of adhesion molecules on cell lines derived from patients with myeloma. The U266, ARH-77, IM-9, and HS-Sultan cell lines strongly expressed beta 1 and alpha 4 integrins (89% to 98% positive), confirming that VLA-4 is the principal integrin on these cell lines. The U266 and IM-9 cell lines also expressed alpha 3 integrin on 15% to 20% cells. In contrast, all lines lacked cell surface alpha 2, alpha 5, and alpha 6 integrin expression (< 5% positive). These cell lines adhered to fibronectin (20% to 40% specific binding), without significant binding to either collagen or laminin. Adhesion of these cell lines to fibronectin was partially blocked with either anti-beta 1 integrin monoclonal antibody (MoAb) (75% inhibition), anti-alpha 4 integrin MoAb (75% inhibition), or RGD peptide (50% inhibition), but was unaffected by anti-alpha v beta 3 or anti-alpha IIb beta 3 MoAbs. Moreover, the combination of anti-beta 1 plus RGD peptide or anti-alpha 4 plus RGD peptide inhibited binding to fibronectin by 80% and 95%, respectively. Finally, pretreatment and coculture of the IM-9 cell line with interleukin-6 (IL-6) resulted in a 52% decrease in specific binding to fibronectin (30% +/- 6% to 15% +/- 6%; P = .001), associated with a decrease in the number of cells expressing VLA-4 and a decrease in intensity of VLA-4 expression. These data suggest that myeloma cells adhere to fibronectin through VLA-4 as well as through RGD-dependent mechanisms, and that this binding can be downregulated by IL-6. Future studies of binding of both myeloma cell lines and freshly isolated tumor cells to extracellular matrix proteins and to marrow stroma may enhance our understanding of localization and trafficking of cells within the bone marrow microenvironment.
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PMID:Characterization of adhesion molecules on human myeloma cell lines. 142 1

We have investigated the ability of an antisense oligonucleotide (ASE-1) to specifically inhibit IgE synthesis by a human myeloma cell line, U266. ASE-1 inhibited IgE production in a concentration-dependent manner, as assessed by isotype-specific ELISA measurement of immunoglobulin in myeloma cell supernatants. Inhibition of IgE production was specific and not due to cytotoxicity since IgG1 and IgM production by human myeloma cell lines ARH-77 and RPMI-1788 respectively, was not significantly affected by up to 20 microM ASE-1 whereas IgE production was inhibited by approximately 70% at this concentration. These results indicate that antisense oligonucleotides represent a potential therapeutic approach to the treatment of IgE-mediated allergic diseases.
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PMID:Specific inhibition of IgE antibody production by an antisense oligodeoxynucleotide oligomer (Oligostick). 147 91

The monoclonal antibody MM4 reacts with human myeloma cells from plasma cell dyscrasia (PCD)-derived cell lines and bone marrow (BM) biopsies from PCD patients, but not with normal BM or peripheral blood mononuclear (PBM) cells. We examined cytotoxicity of MM4 and rabbit complement (MM4:C') on mixtures of normal BM mononuclear cells and myeloma cells from three different PCD-derived cell lines, RPMI 8226, GM 1312, or ARH-77. For cell preparations containing 10% myeloma cells, treatment with MM4 (500 micrograms per 10(5) cells, 4 degrees C, 60 min) and two cycles of complement (1:8, 23 degrees C, 2 x 30 min) consistently eliminated 2 logs or more of clonogenic myeloma stem cells, as determined by colony growth assays and limiting dilution analysis (99.4%, 98.9%, and 99.96% reduction of RPMI 8226, GM 1312, and ARH-77 cells, respectively). The majority of normal marrow progenitors were spared (inhibition of CFU-C: 10-13%; BFU-E: 0%). These observations suggest that MM4 may be useful for selective depletion of human myeloma clonogenic stem cells from bone marrow ex vivo.
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PMID:Selective depletion of human myeloma clonogenic stem cells from bone marrow cell preparations by a plasma-cell reactive antibody and complement. 318 Jan 47

Ricin A chain-containing immunotoxins (IT-As) specific for the human B-cell antigen, CD22, were prepared from 4 monoclonal antibodies (MAbs) or their Fab' fragments: RFB4, HD6, UV22-I and UV22-2. The ITs were tested for their ability to kill cells from the Burkitt lymphoma line, Daudi, the pre-B-cell leukemia line, NALM-6, and the myeloma cell line, ARH-77. Daudi expresses high levels of CD22, whereas NALM-6 and ARH-77 express low levels of CD22. The IgG-RFB4-A was highly toxic to all 3 cell lines; it killed 50% of the Daudi cells at a concentration of 1.2 x 10(-12) M and 50% of NALM-6 and ARH-77 cells at concentrations of 1.5 to 2.1 x 10(-11) M. IgG-RFB4-A was 10-30 times more toxic to Daudi cells than were the IgG-As constructed from the other 3 CD22 MAbs and 10 times more toxic than ricin itself. IT-As constructed from the Fab' fragments of the 4 CD22 antibodies were 2 to 5 times less toxic to Daudi cells than their IgG-A counterparts. Fab'-RFB4-A was twice as toxic to Daudi cells as ricin, whereas the other Fab'-As were about 7 times less toxic than ricin. Scatchard analyses of the binding of the radio-iodinated antibodies to Daudi cells showed that the intact RFB4 antibody bound 3-10 times more strongly than the other antibodies, whereas the Fab'-RFB4 bound 1.2 to 3.5 times more strongly than the Fab' fragments prepared from the other antibodies. Thus, the potent cytotoxic activity of the RFB4-As appears to derive, in part, from their superior binding affinity. Prior studies have shown that UV22-I and HD6 cross-react with certain normal human tissues lacking cells of B-cell lineage, whereas UV22-2 and RFB4 are B-cell-specific. This fact, together with its superior potency as an IT-A, suggests that RFB4 is the antibody of choice for preparing Fab'-As or IgG-As for in vivo therapy of human B-cell leukemias and lymphomas.
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PMID:Evaluation of four CD22 antibodies as ricin A chain-containing immunotoxins for the in vivo therapy of human B-cell leukemias and lymphomas. 326 28

The rate of nucleoside transport decreased profoundly in human promyelocytic leukemia HL-60 cells after myeloid differentiation was induced by 5-6 days of exposure to 0.8% N,N-dimethylformamide (DMF). The facilitated diffusion of 100 microM radiolabeled adenosine and 2'-deoxyadenosine, measured by rapid transport assays, decreased 10- to 20-fold. The transport of 2 microM coformycin or 2'-deoxycoformycin, which is mediated by the same mechanism and was monitored by the adenosine deaminase titration assay, decreased 29-fold. The reduction in nucleoside transport capacity after DMF treatment was confirmed by a 19-fold decrease in the number of specific binding sites per cell (from 24-30 X 10(4) to 1.2-1.7 X 10(4)) for [3H]-6-p-nitrobenzylthioinosine, a nucleoside transport inhibitor. The binding affinity of 6-p-nitrobenzylthioinosine was not altered significantly and nucleoside transport remained sensitive to the transport inhibitors, 6-p-nitrobenzylthioinosine, dipyridamole, and dilazep after DMF-induced maturation. Time-dependence studies showed that the rate of 100 microM deoxyadenosine transport was unchanged for the first 24 h of exposure to DMF but fell to about 36% of control rates at 24-26 h and then gradually decreased further to about 4-5% of control rates after 5-6 days. In contrast, transport rates of the purine bases were reduced only 2- to 3-fold in HL-60 cells after 5 days of DMF treatment. The rates of adenosine and deoxyadenosine transport were unchanged or reduced by no more than 2-fold after 5-6 days of exposure to 0.8% DMF in the following human tumor cell lines that are not inducible with DMF: ARH-77 (multiple myeloma), KG-1 (acute myelogenous), and K-562 (chronic myelogenous). Thus, changes in nucleoside transport may serve as an early, membrane-associated marker of differentiation of the HL-60 cell line.
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PMID:Changes in nucleoside transport of HL-60 human promyelocytic cells during N,N-dimethylformamide induced differentiation. 348 11

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 blue exclusion assays. The same treatment eliminated greater than 99% of clonogenic myeloma stem cell colony formation of these cell lines, with less than 20% inhibition of normal human bone marrow pleuripotent progenitor colony formation in vitro. As an experimental model to explore the efficacy of MM4 + C' in purging MM-involved bone marrow, normal marrow cells were mixed with RPMI 8226 or GM 1312 cells in the ratio of 90:10 or 50:50 (marrow:myeloma cells). Colony growth assays indicated that MM4 + C' eliminated at least 2 logs of clonogenic myeloma stem cells in both 90:10 and 50:50 preparations, while sparing the majority of normal marrow progenitors (inhibition of CFU-C:10% to 13%; BFU-E:0%). The selectivity of MM4-mediated cytotoxicity may be useful for eliminating myeloma clonogenic stem cells from bone marrow of patients with multiple myeloma.
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PMID:Elimination of clonogenic stem cells from human multiple myeloma cell lines by a plasma cell-reactive monoclonal antibody and complement. 366 43

Effects of a 7-day treatment with the maturational agents DMF and sodium butyrate on enzymes of pyrimidine metabolism, growth rate and cell maturation were assessed in 5 human tumor cell lines, ARH-77 (myeloma), K-562 (chronic myeloid leukemia), KG-1 (myeloid leukemia), HL-60 (promyelocytic leukemia) and RWLy-1 (non-Hodgkin's lymphoma). DMF lengthened the doubling times of all five cell lines while sodium butyrate lengthened only those of K-562, HL-60 and RWLy-1. Full maturation was induced only in HL-60 by either agent and in K-562 by butyrate. Exposure resulted in a decreased activity of the anabolic enzyme orotate phosphoribosyltransferase (EC 2.4.2.10) and increased activities of the catabolic enzymes thymidine phosphorylase (EC 2.4.2.4) and dihydrouracil dehydrogenase (EC 1.3.1.2). Changes in the amphibolic enzyme, uridine phosphorylase (EC 2.4.2.3) did not follow any apparent pattern. This study indicates that the pattern of pyrimidine metabolism differs between the differentiated and slowly growing, and undifferentiated rapidly growing counterpart of several human tumors, suggesting that enzymes of pyrimidine metabolism can be used as markers for cellular growth and/or maturity.
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PMID:Effects of N,N-dimethylformamide and sodium butyrate on enzymes of pyrimidine metabolism in cultured human tumor cells. 368 65


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