Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this report we demonstrate that retinoic acid (RA) down-regulated the number of IL-6R on human leukocyte cell lines, including the myeloma cell line AF10, and two B cell hybridomas that correspond to cells at earlier stages of B cell development. Using AF10 cells, whose growth was determined to be mediated by the autocrine action of IL-6, we found that RA reduction of IL-6R was concentration-dependent over a range of 10(-11) to 10(-5) M and corresponded to the ability of the retinoid to inhibit cell proliferation. The down-regulation of IL-6R number by RA was accompanied by reduced IL-6R mRNA expression. RA did not affect endogeneous IL-6 synthesis or secretion from AF10 cells. However, addition of exogenous rIL-6 could overcome RA-induced growth inhibition. Menthol, a structurally unrelated compound to RA, also suppressed IL-6R expression and, correspondingly, inhibited cell growth. Taken together, our results suggest that the antiproliferative action of RA on AF10 cells is caused by reduction of IL-6R expression and subsequent inhibition of IL-6-mediated autocrine growth. These findings suggest the possibility that down-regulation of IL-6R is a means by which RA can modulate immune function.
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PMID:Retinoic acid-induced growth inhibition of a human myeloma cell line via down-regulation of IL-6 receptors. 203 52

A STA was observed in a human-derived myeloma cell line, AF10, that produces IgE paraprotein. The STA in the culture medium of the AF10 myeloma cell line was associated in the 24 to 48 hr period of incubation with IgE biosynthesis, and increased thereafter up to 72 hr, while IgE remained stable. These data support our previous observations that human myeloma cells are associated with a relatively high production of sialyltransferase, which is released to the medium, presumably by a mechanism of shedding.
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PMID:Sialyltransferase activity in AF10 myeloma cell line. 225 11

Macrophage CSF (M-CSF) induces proliferation of monocyte/macrophage progenitor cells and can also activate some functions of mature cells. Three different human M-CSF cDNA (4.0, 3 to 3.5, and 1.5 kb) which are the result of alternative splicing of the single M-CSF gene have been cloned. Each of these cDNA encode a biologically active M-CSF. M-CSF transcripts are expressed in normal fibroblasts and other mesenchymal cells, and also in some hematopoietic cells such as monocytes. Normal human cells examined to date express only the 4.0-kb transcript. In contrast, a 3.5-kb M-CSF transcript was continuously expressed in two multiple myeloma cell lines (RPMI 8226 and U266/AF10) and in a bone marrow specimen of a patient with multiple myeloma. The myeloma cell lines secreted biologically active M-CSF. Resting and activated normal B lymphocytes and other B cell neoplasms examined did not express the 3.5-kb transcript, but could be induced to express the 4.0-kb transcript and to secrete M-CSF. Myeloma cells appear to be unique among hematopoietic cells in their expression of the 3.5-kb M-CSF transcript.
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PMID:Expression of a novel 3.5-kb macrophage colony-stimulating factor transcript in human myeloma cells. 268 19

Interferon-alpha and the synthetic glucocorticoid dexamethasone are used in the treatment of multiple myeloma. The effect of 48 h exposure to recombinant interferon-alpha 2b (100 to 10,000 U/ml) and dexamethasone (1 microM to 1 mM) was studied in AF10, and IgE-secreting myeloma cell line. Interferon-alpha and dexamethasone at 10,000 U/ml and 1 mM respectively had a synergistic inhibitory effect on IgE concentration. Interferon-alpha and dexamethasone had an additive inhibitory effect on myeloma cell concentration. Interferon-alpha at 10,000 U/ml caused a twofold increase in sialyltransferase activity. Dexamethasone decreased sialytransferase activity and attenuated the stimulatory effect of interferon-alpha. These data suggest that combined interferon-alpha and dexamethasone therapy might have a synergistic effect on monoclonal protein production and a diverse effect on sialytransferase activity.
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PMID:Interferon-alpha and dexamethasone effect on AF10 myeloma cell line sialytransferase activity. 837 39

AF10, a human B cell line, is a mycoplasma-free variant cloned from the human IgE myeloma cell line U266. Total RNA isolated from the AF10 cells was used as template for RT-PCR, and a specific product of about 411bp corresponding to the coding region of hIL-17 lack of a leading sequence obtained. The sequence of the RT-PCR product is the same to that reported in the literature. The expressed rhIL-17 in E. coli can induce 10- to 15-fold increase of IL-6 secretion by mouse fibroblast 3T3 cells. It is for the first time until now that hIL-17 messager has been detected in B cell. There may exist some potential relationship between hIL-17 and myeloma cells.
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PMID:A human B cell line AF10 expressing HIL-17. 976 9

Most current methods for identifying peptides that are bound to a distinct MHC-I product in a given cell sample utilize detergent solubilization of membrane proteins followed by immunoaffinity purification. Since detergent traces and cell debris hamper subsequent peptide analysis, exceedingly large cell samples are often required. To avoid the use of detergents, truncated MHC-I heavy chains have recently been expressed by stable DNA transfection or retroviral transduction, resulting in the secretion of soluble MHC-I complexes to the growth medium. The electroporation of in vitro-transcribed mRNA achieves remarkable efficacy and uniformity of gene expression in numerous cell types, exhibiting exceedingly fast kinetics. We reasoned that mRNA transfection offers a simple, fast and widely applicable alternative to current gene delivery protocols for expressing secreted MHC-I products in cells of interest. To test this assumption we used mRNA to express soluble derivatives of HLA-A2 in the human AF10 B cell myeloma and 624mel melanoma and H-2K(d) in the mouse SP2/0 B cell myeloma. The level of MHC-I complexes secreted by these cells peaked within less than 24h post-transfection and they could be affinity-purified directly from the culture medium in considerably greater yields when compared to nonionic detergent lysates on a cell-to-cell basis. Mass-spectrometry analysis of eluted peptides revealed larger pools in the secreted material than in lysates with substantial overlap in composition. Our results introduce mRNA transfection as a powerful tool for determining the cell's MHC-I peptidome, which can be potentially applied to a broad range of cell types.
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PMID:Efficient peptide recovery from secreted recombinant MHC-I molecules expressed via mRNA transfection. 2583 26