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)

Modulation of the expression of P-glycoprotein, a plasma membrane protein associated with multidrug resistance, was examined in drug-sensitive and drug-resistant tumor cells treated with leukoregulin, a M(r) 50,000 cytokine from human lymphocytes that rapidly permeabilizes the plasma membrane of many tumor cells facilitating the uptake of doxorubicin and other tumor-inhibitory antibiotics. P-glycoprotein expression was measured flow cytometrically by the binding of C219 or MRK16 monoclonal antibody to multidrug-sensitive human K562 erythroleukemia and 8226/S myeloma cells, compared to multidrug-resistant 8226/DOX40 myeloma cells. Cells were treated for up to 2 h with up to 80 units of leukoregulin/ml or one of a variety of unrelated cytokines including interleukin 1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, colony-stimulating factor, macrophage colony-stimulating factor, granulocyte macrophage colony-stimulating factor, tumor necrosis factor alpha, gamma-interferon, alpha-interferon, epidermal growth factor, platelet-derived growth factor AA, platelet-derived growth factor BB, insulin-like growth factor I, insulin-like growth factor II, fibroblast growth factor, or transforming growth factor beta. Leukoregulin caused a concentration-dependent decrease in P-glycoprotein expression; however, P-glycoprotein expression was unaffected by the other cytokines (< 12% decrease in expression). Leukoregulin-induced membrane permeabilization, determined flow cytometrically by intracellular fluorescein efflux, and decreased P-glycoprotein expression occurred simultaneously within 15 min in drug-sensitive and -resistant cells. Enhanced doxorubicin uptake, measured flow cytometrically by doxorubicin influx, was also present within 15 min. Leukoregulin enhancement of doxorubicin uptake and increased membrane permeability varied directly with the decrease in P-glycoprotein expression. Leukoregulin in combination with doxorubicin enhanced the inhibition of cell proliferation in 8226/DOX40 multidrug-resistant cells over expressing P-glycoprotein. In contrast, combined treatment of HL-60/MX2 multidrug-resistant human promyelocytic leukemia cells that do not overexpress P-glycoprotein in association with their multidrug resistance resulted in no greater growth inhibition than observed with HL-60/MX2 cells treated with doxorubicin alone. This is the first demonstration that a naturally occurring macromolecule with anticancer activities can modulate the expression of P-glycoprotein concomitant with enhanced drug uptake and inhibition of cell proliferation.
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PMID:Decreased P-glycoprotein expression in multidrug-sensitive and -resistant human myeloma cells induced by the cytokine leukoregulin. 135 22

Actinobacillus actinomycetemcomitans produces a cytolytic peptide leukotoxin which kills susceptible target cells, including human neutrophils, monocytes, lymphocytes, and HL-60 promyelocytic leukemia cells. Cell death occurs as a consequence of colloid osmotic lysis. In the present investigation early leukotoxin-induced changes in membrane permeability were studied by flow cytometry and quantitative spectrofluorimetry in leukotoxin-susceptible and resistant targets. Within 5 s toxin-susceptible cells exhibited concentration-dependent, sustained increases in systolic free Ca2+, and this was rapidly followed by a progressive fall in membrane potential. These early manifestations of membrane injury occurred approximately 10-15 min before cell death, as reflected by flow cytometric analysis of propidium iodide stained cells. The rise in cytosolic Ca2+ was almost entirely due to an influx of extracellular Ca2+. The results of Hill plots for the action of leukotoxin on Ca2+ permeability in human neutrophils or HL-60 cells suggested that two or more toxin molecules participate in the assembly of an ion conducting pore in the plasma membrane. Changes in membrane permeability or cell viability were not observed in response to heat-inactivated toxin. Under appropriate conditions toxin-induced membrane abnormalities were inhibited by leukotoxin-neutralizing mAb or relatively high concentrations (greater than or equal to 2.5 mM) of extracellular Ca2+. Leukotoxin-resistant target cells showed no evidence of membrane injury even when exposed to high concentrations of leukotoxin for prolonged periods of time. These included resistant human K562 erythroleukemia cells and murine SP2 myeloma cells which have previously been shown to adsorb the toxin, suggesting that they possess a protective mechanism(s) which impedes toxin insertion or assembly in the lipid bilayer. These data support the concept that A. actinomycetemcomitans leukotoxin acts as a cell-specific, pore-forming protein which permeabilizes the plasma membrane of susceptible target cells.
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PMID:Early changes in cytosolic calcium and membrane potential induced by Actinobacillus actinomycetemcomitans leukotoxin in susceptible and resistant target cells. 194 Mar 58

We have isolated and sequenced cDNA clones encoding the human homolog of the mouse Lyb-2 B cell differentiation Ag. Previous data suggest that Lyb-2 might represent a growth factor or lymphokine receptor. Human Lyb-2 mRNA is expressed in normal human tonsils and bone marrow cells, in the pre-B cell line REH, in three Burkitt lymphoma cell lines, and in some EBV-transformed B cell lines, but not in antibody-secreting myeloma cell lines, T cell lines, or a promyelocytic leukemia cell line. These data indicate that expression of human Lyb-2 is restricted to B lineage cells and turned off in antibody-secreting plasma cells. A polyclonal mouse antiserum was raised against human Lyb-2 and immunoprecipitates a Mr 42,000 protein from REH, Raji, and Daudi cells and from mouse L(tk) cells transfected with the human Lyb-2 cDNA in an expression vector. The human Lyb-2 protein is related to both the asialoglycoprotein receptor and CD23, the B cell-specific FcR for IgE. These data demonstrate that human B cells express a previously undescribed cell surface protein that is homologous to mouse Lyb-2 and has a similar pattern of expression during B cell development.
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PMID:Identification of a human protein homologous to the mouse Lyb-2 B cell differentiation antigen and sequence of the corresponding cDNA. 214 Oct 45

Using immunofluorescence microscopy and immunoblot analysis, we have examined the composition of the nuclear lamina in several murine and human cell lines. Whereas it was shown that intermediate filament-positive Ehrlich ascites tumor and HeLa-S3 cells contain the three major mammalian lamin subspecies, only lamin B could be detected in several myeloid- and lymphoid-derived cell lines representative of distinct stages in hemopoietic differentiation but all devoid of cytoplasmic intermediate filament proteins. These included the murine plasmacytoma cell types MPC-11 and MOPC-31C, murine myeloma cells X63-Ag8.6.5.3 and human promyelocytic leukemia cells HL-60. Our results provide the first evidence that mammalian somatic cells capable of normal proliferation may lack both cytoplasmic intermediate filament proteins and a normal complement of nuclear lamins.
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PMID:Lack of lamins A and C in mammalian hemopoietic cell lines devoid of intermediate filament proteins. 306 54

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

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

There is evidence that polymorphonuclear granulocytes release neutral proteinases such as elastase (E) and cathepsin G in the course of acute leukemia. These proteinases may inactivate clotting factors by unspecific degradation before they are eliminated via complex formation with endogenous inhibitors, e.g. the alpha 1-proteinase inhibitor (alpha 1-PI). In this study it was attempted to correlate plasma levels of the E-alpha 1-PI complex with factor XIII and antithrombin III in acute leukemia. Using a newly developed, sensitive enzyme-linked immunoassay the concentration of E-alpha 1-PI in patients with various types of leukemia, malignant lymphoma or multiple myeloma was determined. Only patients with acute myelocytic or promyelocytic leukemia (AML, APL) and chronic myelocytic leukemia with and without blastic transformation (CML) showed moderate to high levels of E-alpha 1-PI (2- to 20-fold of normal). However, coagulation factor concentration observed in the different types of leukemia seemed to be independent of elastase liberation. Most of the AML-patients with elevated E-alpha 1-PI levels showed peroxidase positive blood cell smears.
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PMID:Plasma levels of human granulocytic elastase alpha 1-proteinase inhibitor complex (E-alpha 1-PI) in leukemia. 637 1

A murine hybridoma-derived monoclonal antibody, PM-81, was obtained from a fusion of cells of the NS-1 myeloma cell line with cells from a mouse immunized with the HL-60 promyelocytic leukemia cell line. This cytotoxic IgM monoclonal antibody was specific for myeloid cells. Employing indirect immunofluorescence and flow cytometry, we determined that this antibody reacts strongly with normal human granulocytes, eosinophils, and monocytes but not lymphocytes (including phytohemagglutinin-activated lymphocytes), null cells, red blood cells, or platelets. Moreover, the PM-81 antibody reacts with leukemia cells from 19 of 22 patients with acute myelocytic leukemia of all FAB subclasses, three of three patients with common acute lymphocytic leukemia, four of four patients with chronic myelocytic leukemia (CML) in myeloid blast crisis (terminal transferase (TdT)-negative) but did not react with cells from two patients with CML in lymphoid blast crisis (TdT-positive) or five patients with chronic lymphocytic leukemia. The myeloid cell lines HL-60, K562, KG-1, and U937 were all reactive with PM-81. The lymphoid lines CCRF-CEM and Daudi did not express PM-81 but HSB-2 was positive. The PM-81 antigen was absent on myeloid and erythroid progenitor cells as determined by their insusceptibility to complement-dependent lysis. In addition, only PM-81-unreactive cells were capable of colony formation. Furthermore, the PM-81 antibody does not appear to induce modulation of the antigen to which it binds. Thus, this monoclonal antibody appears to fulfill several criteria for clinical utility in the diagnosis and treatment of both acute myelocytic and acute lymphocytic leukemia.
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PMID:A unique antigen expressed on myeloid cells and acute leukemia blast cells defined by a monoclonal antibody. 657 89

A monoclonal antibody (MAb) HL-C5, which bound selectively to cells of the myeloid lineage tested, was derived from a fusion between P3/NS2/1-AG8 myeloma cells and splenocytes from a mouse immunized with cells of the promyelocytic leukemia line HL-60. Among a panel of 29 human cell lines derived from either hematopoietic or solid tumors, MAb HL-C5 was found to react exclusively with cells from the five differentiated acute myeloid leukemia lines, HL-60, ML1, ML2, ML3, KG-1B and not with the less differentiated myeloid lines. Fluorescence-activated cell sorter analysis of normal bone marrow samples confirmed that the reactivity of MAb HL-C5 was limited to myeloid cells, from the promyelocytic stage of differentiation to the mature granulocytes. Indirect immunoperoxidase staining of cytocentrifuge preparations of normal bone marrow and peripheral blood leukocytes confirmed these results and showed that MAb HL-C5 stained neutrophils but not eosinophils or basophils. The antigen recognized by HL-C5 was recovered in the upper phase of chloroform-methanol-water lipid extracts prepared from HL-60 cells. By competitive binding experiments, it was found that MAb HL-C5 recognizes the same antigenic determinant as MAb WGHS 29-1, which has been reported to react with glycolipids containing the sugar sequence lacto-N-fucopentaose 111. Autoradiographs of thin layer chromatograms of HL-60 glycolipid extracts which were revealed by incubation with MAb HL-C5 or WGHS 29-1 followed by the addition of 125I-labelled rabbit anti-mouse immunoglobulin antibody confirmed that the two MAbs reacted with the same or structurally very similar glycolipids.
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PMID:Identification by a monoclonal antibody of a glycolipid highly expressed by cells from the human myeloid lineage. 657 67

Lap18 is a highly conserved cytosolic protein that is expressed in dividing cells. Data from a number of studies show that a range of cell lines and mitogen-stimulated normal cells cultured in PMA phosphorylate and subsequently down-regulate Lap18. This has been found to be associated with growth arrest, although it is not clear that these events are causally related. In the present study we confirm that the HL60 promyelocytic leukemia and K562 erythroleukemia cell lines, when cultured with PMA, behave in this manner. This was not the case for any of five mouse plasmacytoma cell lines and six lines derived from patients with multiple myeloma or plasma cell leukemia. All of these lines contain Lap18, although the level of this protein in the mouse but not the human plasmacytoma cell-line cells is relatively low. All the neoplastic plasma cell-line cells phosphorylate Lap18 on culture with PMA, but this does not induce growth arrest nor result in down-regulation of Lap18 expression. Further experiments are required to test whether there is a mechanistic relationship between the continued growth of plasmacytoma cell lines and their failure to down-regulate Lap18 on culture in PMA.
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PMID:Persistent growth of BALB/C mouse plasmacytoma and human myeloma cell lines in the presence of phorbol myristate acetate is associated with continued expression of Lap18 (stathmin). 775 Sep 26


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