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)

The expression of HLA class II molecules is mainly regulated transcriptionally and this regulation is thought to play an important role to the control of immune response. In this report, we have studied the effect of adenylate cyclase activator, forskolin, to the expression of HLA class II molecules on the cell surface of an human multiple myeloma cell line, RPMI8226. On the northern blot analysis and FACS analysis, we have revealed that forskolin upregulated the expression of mRNAs of DQB and DRB gene and their products on its surface. On the sequence analysis of upstream of HLA-DQB gene, we have identified not only Y-,X-, W-box, which were thought to regulatory region of truncated gene, but also cAMP responsible element (CRE) like regulatory region, which located upstream of W-box. On the gel retardation assay, when we used DNA probes that were specific for CRE like region and Y-box, we have found newly detectable bands, which appeared by forskolin treatment. These data suggest that forskolin upregulates HLA class II molecules by means of the interaction between CRE and cAMP responsible element binding protein (CREB).
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PMID:[Analysis of the regulation of HLA class II genes by forskolin]. 132 79

Four monoclonal antibodies to the thyrotropin (TSH) receptor were established by fusing human peripheral lymphocytes of patients from Graves' disease with a human myeloma cell line. Of two antibodies with TSH-binding inhibitory immunoglobulin activity (TBII), one inhibited TSH stimulation of adenylate cyclase and another stimulated adenylate cyclase. These antibodies showed competitive and noncompetitive modes of binding inhibition, respectively. Of the other two antibodies without TBII activity, one stimulated adenylate cyclase and the other inhibited TSH stimulation of adenylate cyclase. Of the two antibodies, which inhibited TSH stimulation of adenylate cyclase, one with TBII activity inhibited stimulation of adenylate cyclase by stimulating antibody with TBII activity, but another without TBII activity inhibited stimulation by both stimulating antibodies with or without TBII activity. These inhibitory antibodies did not influence the stimulation of adenylate cyclase by Forskolin and guanosine 5'-(beta,gamma-imido)triphosphate compounds which are known to affect other parts of the receptor-adenylate cyclase system than the receptor unit. Four antibodies with heterogeneous potencies to the TSH receptor reacted with glycoproteins extracted from thyroid membranes. One stimulating antibody without TBII activity also interacted with the glycolipid fraction of the membrane preparation, and the binding decreased after desialylation or deglycosylation of the membrane components. In order to identify the binding sites of these monoclonal antibodies, receptor proteins interacting with antibodies were visualized by Western blot analysis and by the label transfer cross-linking method. All of these antibodies with different characteristics reacted with a 56-kDa molecule.
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PMID:Monoclonal antibodies to the thyrotropin receptor bind to a 56-kDa subunit of the thyrotropin receptor and show heterogeneous bioactivities. 246 Apr 48

Using a recently described cell line derived from the fusion of human thyroid and human myeloma cells, we studied the effects of TSH on cell growth, iodide organification, and cAMP production. Although these cells grow in the absence of TSH, when incubated for 2 days in serum-free medium containing purified human or bovine TSH, there was a significant increase in cellular DNA content. The stimulatory effect was observed at concentrations as low as 0.5 microU/ml, which produced a significant increase in DNA content, and was maximal with 5 microU/ml. This effect was still present after 6 days of incubation. Electron microscopy performed by an unbiased observer on cells incubated in the presence of TSH showed an increase in the calculated size of the cells and the nucleus which was significant at 0.1 microU/ml and maximal at 1 microU/ml. Stimulation of 125I organification and hormone production was observed at TSH concentrations as low as 1 microU/ml and was maximal at 10 microU/ml. However, neither TSH (1-50 microU/ml) nor forskolin (10(-6) M) stimulated cAMP production. These data suggest that these cells lack a functional adenylate cyclase pathway and that growth and iodide organification are mediated by other second messenger systems. Such a cell line could yield new insights into the mechanisms of TSH action and may provide a sensitive bioassay for TSH and other thyrotropic factors.
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PMID:Thyrotropin induces growth and iodothyronine production in a human thyroid cell line without affecting adenosine 3',5'-monophosphate production. 284 54

We have developed two types of hybridomas producing monoclonal antibodies to the turkey erythrocyte beta 1-adrenergic receptor in order to study the beta-adrenergic-cAMP system of epidermis. Splenic cells from BALB/c mice immunized with partially purified turkey erythrocyte beta 1-receptors were fused with mouse myeloma cell line SP2/0-Ag14. Five hybridomas of 17 positive cells producing antibodies which could precipitate soluble turkey erythrocyte beta 1-receptors were cloned by the limiting dilution method. The antibodies cross-reacted with beta 1- and beta 2-adrenergic receptors and stained epidermal basal cells with immunocytochemical techniques. Neither type of antibody interfered with the antagonist binding, i.e., all antibodies bound to sites other than the ligand binding site on the surface. One type of antibody inhibited epinephrine-stimulated adenylate cyclase activity in our "leaky" epidermal cell system. The data suggest that the antibody interferes with the coupling of the receptor to the regulatory protein.
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PMID:Monoclonal antibodies to the beta-adrenergic receptor: modulation of catecholamine-sensitive adenylate cyclase by the antibody. 301 55

Recent studies revealed that anti-TSH receptor autoantibodies are involved in the pathogenesis of both Graves' disease and a part of hypothyroidism, but precise mechanism of action of these antibodies remained to be studied. In order to delineate the heterogeneity of these antibodies and their pathophysiological significance, we produced monoclonal antibodies to TSH receptor and studied their characteristics. Mouse monoclonal antibodies to TSH receptor were derived from spleen cells of mice immunized with partially purified human TSH receptor, which was prepared by TSH-coupled affinity chromatography of thyroid membrane solubilized with Triton X-100. By fusing spleen cells and mouse myeloma cells in the presence of polyethylene glycol and selecting with limiting dilution method, 5 hybridomas were obtained. Among 3 antibodies, which inhibited TSH binding to thyroid membrane (TSH displacing activity, TDA), 2 inhibited TSH stimulation of thyroid adenylate cyclase (AC) (human thyroid adenylate cyclase inhibitor activity, HTACI), and one showed no bioactivity. Among other 2 antibodies without TDA, 1 stimulated AC (human thyroid adenylate cyclase stimulator activity, HTACS) and the other inhibited TSH stimulation (HTACI). All activities of these antibodies were dependent on IgG concentration and disappeared by treatment of anti-mouse IgG antibodies. In addition, 4 human-human hybridomas were established by fusing human peripheral lymphocytes of patients with Graves' disease and nongoitrous hypothyroidism with human lymphoblastoid cell line. Among 2 antibodies with TDA, one antibody inhibited TSH stimulation of AC, inhibiting TSH binding competitively and another antibody stimulated AC, inhibiting TSH binding noncompetitively. Among the other 2 antibodies, which did not inhibit TSH binding but were shown to bind to TSH receptor by immunoprecipitation, one stimulated AC and the other inhibited TSH stimulation of AC. Among 2 antibodies with HTACI, one antibody with positive TDA inhibited stimulation of AC by stimulative antibodies with positive TDA, but the other without TDA inhibited stimulation of AC by both antibodies with or without positive TDA. These inhibitory antibodies did not inhibit stimulation of AC by Forskolin and Gpp(NH)p, which are known to affect other parts of receptor-AC system than receptor unit. These data suggest that anti-TSH receptor antibodies are heterogenous in the mode of binding to the receptor and in their bioactivities, and may be involved in the pathogenesis of both Graves' disease and a part of idiopathic hypothyroidism.
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PMID:[Studies on monoclonal antibodies to TSH receptors--heterogeneity and pathophysiological significance of antibodies to TSH receptor]. 381 31

Supernatant fluids from the cultures of bone marrow cells from 10 of 12 patients with multiple myeloma (MM) caused bone resorption in organ cultures of fetal rat calvaria. In four patients, the marrow cells were cultured with and without indomethacin (1 muM). The supernatant fluids from indomethacintreated marrow cultures caused significantly less bone resorption than supernatant fluids of cell cultures without indomethacin. This inhibition of release of bone resorbing factor(s) by myeloma cultures is similar to the previously observed indomethacin-induced inhibition of osteoclast-activating factor (OAF) production by activated human leukocytes. None of the MM supernatants had any effect on cyclic (c)AMP accumulation in resorbing bone in vitro. Four separate preparations of partially purified OAF obtained from phytohemagglutinin-stimulated peripheral human leukocytes were tested for their ability (a) to cause bone resorption in organ cultures of fetal rat and neonatal mouse calvaria and (b) to cause accumulation of cAMP in rat and mouse skeletal tissue in vitro. Those dilutions of OAF that caused bone resorption had no effect on accumulation of cAMP in rat or mouse calvaria incubated in vitro. In addition, no stimulation of adenylate cyclase activity in membranes prepared from fetal rat calvaria could be found. Bone cell populations isolated by sequential collagenase digestion of fetal rat calvaria also showed no cAMP response to these dilutions of OAF. Parathyroid hormone caused a clear response in all three systems. Furthermore, no cAMP response to OAF was observed in calvaria in the presence of cholera toxin (1 mug/ml) and isobutyl-methylxanthine (0.3 mM). These observations demonstrate that (a) supernatant fluids from MM marrow cultures stimulate bone resorption but do not increase cAMP accumulation in vitro; (b) indomethacin interferes with the release of bone resorbing factors by MM bone marrow cultures suggesting that this process requires prostaglandins; and (c) Sephadex G100 or G75 purified OAF does not stimulate adenylate cyclase or increase cAMP accumulation at equivalent bone resorbing concentrations in rat and mouse skeletal tissue. The resorptive action of MM culture fluids is similar to that of partially purified OAF from activated cultured leukocytes, but different from those of other bone resorbing factors, parathyroid hormone and prostaglandin E(2), which stimulate cAMP production in skeletal tissue.
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PMID:Observations on the mechanism of bone resorption induced by multiple myeloma marrow culture fluids and partially purified osteoclast-activating factor. 626 78

Hybridoma cells have been obtained by fusing P3-NS1/1-Ag4-1 mouse myeloma cells with spleen cells from mice immunized with solubilized preparations of the thyrotropin receptor. Five clones were produced that secrete a monoclonal antibody whose binding to thyroid membranes is specifically inhibited by unlabeled thyrotropin. The antibody interacts with functioning thyroid cells in culture but not with nonfunctioning cells; this interaction is prevented by thyrotropin. The antibodies are capable of competitively blocking thyrotropin binding to bovine thyroid membrane preparations; they prevent 125I-labeled thyrotropin binding to a solubilized preparation of the glycoprotein component of the bovine thyrotropin receptor but are unable to inhibit 125I-labeled thyrotropin binding to liposomes containing gangliosides at comparable concentrations. They prevent 125I-labeled thyrotropin binding to rat, bovine, or human (Graves disease) thyroid membrane preparations. They do not stimulate adenylate cyclase activity in thyroid membrane preparations but can inhibit thyrotropin-stimulated iodide uptake by functioning thyroid cells in culture.
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PMID:Monoclonal antibodies to the thyrotropin receptor: implications for receptor structure and the action of autoantibodies in Graves disease. 626 39

Monoclonal antibodies to the thyrotropin (TSH) receptor have been obtained from fusions of mouse myeloma cells with spleen cells immunized with solubilized thyroid membrane preparations. Two monoclonal antibodies which inhibit 125I-TSH binding and are reactive with the glycoprotein component of the bovine TSH receptor (11E8 and 13D11), are shown to inhibit basal and TSH stimulated adenylate cyclase activity in bovine thyroid membranes and human thyroid cells. Both antibodies also inhibit 125I-TSH binding in vitro, whether binding is measured at pH 6.0 in low salts and at 0-4 C or at pH 7.4 in 50 mM NaCl and at 37 C. The glycoprotein component is thus a portion of the physiologic TSH receptor in vivo and 125I-TSH binding studies apparently measure the high affinity glycoprotein component under nonphysiologic conditions and conditions more representative of the physiologic milieu. A third monoclonal antibody whose interaction with thyroid membranes is prevented by TSH is shown to stimulate adenylate cyclase activity in bovine thyroid membranes and human thyroid cells. This stimulating antibody only weakly inhibits 125I-TSH binding to thyroid membranes or to the glycoprotein component of the TSH receptor. The 22A6 antibody does, however, immunoprecipitate mixed brain gangliosides, in distinct contrast to the monoclonal antibodies to the glycoprotein receptor component, i.e., 11E8 and 13D11. The results support the speculation that autoimmune antibodies which inhibit TSH binding to thyroid membranes are not necessarily identical to antibodies which stimulate function; that antibodies directed at the high affinity initial site of TSH interaction with a cell can behave as blocking rather than stimulating antibodies and that a possible relationship exists between stimulating antibodies and the low affinity TSH binding sites (gangliosides) on thyroid membranes.
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PMID:Monoclonal antibodies to the thyrotropin receptor: the identification of blocking and stimulating antibodies. 629 19

Activation of early response genes by interferons (IFNs) requires tyrosine phosphorylation of the Stat transcription factors and is mediated by the Jak family of tyrosine kinases. Recent evidence suggests that ERK2 serine/threonine kinase modulates the IFN-stimulated Jak/Stat pathway. In this report we show that in the myeloma cell line U266 protein kinase A specifically interacts with the cytoplasmic domain of the IFNalpha/beta receptor. Treatment of cells with the adenylate cyclase activator forskolin inhibits IFNbeta-, IFNgamma-, and hydrogen peroxide/vanadate-induced formation of complexes that bind to enhancers known to stimulate the expression of IFN-regulated genes. Immunoprecipitations followed by anti-phosphotyrosine immunoblots indicate that tyrosine phosphorylation of the alpha chain of the IFNalpha/beta receptor, Jak1, Tyk2, as well as Stat1 and Stat2 is reduced as a consequence of incubation of cells with forskolin. In contrast, dideoxyforskolin, which fails to activate adenylate cyclase, has no effect on IFN induction of the Jak/Stat pathway. These results indicate a novel regulatory mechanism by which protein kinase A can modulate the Jak/Stat signaling cascade.
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PMID:Activation of protein kinase A inhibits interferon induction of the Jak/Stat pathway in U266 cells. 861 15

Despite the introduction of new therapies for multiple myeloma (MM), many patients are still dying from this disease and novel treatments are urgently needed. We have designed a novel hybrid molecule, called NEO214, that was generated by covalent conjugation of the natural monoterpene perillyl alcohol (POH), an inducer of endoplasmic reticulum (ER) stress, to rolipram (Rp), an inhibitor of phosphodiesterase-4 (PDE4). Its potential anticancer effects were investigated in a panel of MM cell lines. We found that NEO214 effectively killed MM cells in vitro with a potency that was over an order of magnitude stronger than that of its individual components, either alone or in combination. The cytotoxic mechanism of NEO214 involved severe ER stress and prolonged induction of CCAAT/enhancer-binding protein homologous protein (CHOP), a key pro-apoptotic component of the ER stress response. These effects were prevented by salubrinal, a pharmacologic inhibitor of ER stress, and by CHOP gene knockout. Conversely, combination of NEO214 with bortezomib, a drug in clinical use for patients with MM, resulted in synergistic enhancement of MM cell death. Combination with the adenylate cyclase stimulant forskolin did not enhance NEO214 impact, indicating that cyclic adenosine 3',5'-monophosphate (AMP) pathways might play a lesser role. Our study introduces the novel agent NEO214 as a potent inducer of ER stress with significant anti-MM activity in vitro. It should be further investigated as a potential MM therapy aimed at exploiting this tumor's distinct sensitivity to ER stress.
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PMID:Induction of Pro-Apoptotic Endoplasmic Reticulum Stress in Multiple Myeloma Cells by NEO214, Perillyl Alcohol Conjugated to Rolipram. 2934 25


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