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)

Exposure of a myeloma cell line (RPMI 8226) to a 30-minute pulse of melphalan (1-phenylalanine-mustard) resulted in a cell cycle progression delay characteristic for DNA cross-linking agents. Reduction of outflow of cells from late S- and G2-phases was more pronounced as compared to that from G1-phase. The consequence is a progressive accumulation of cells in late S- and G2-phases. At restoration of outflow of cells from late S- and G2-phases, complete removal of DNA interstrand cross-links, as measured by DNA alkaline elution, was noted. At this time less than 50% of maximum DNA-protein cross-links were removed. Further we found no correlation between restored outflow of cells from the G2-phase and removal of DNA-protein cross-links during the follow-up time of 72 h. No DNA double strand breaks as measured by DNA neutral elution were formed during the observation period. The data suggest that removal of DNA interstrand cross-links seems prerequisite for the outflow of cells from G2 after melphalan treatment.
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PMID:Cell cycle arrest and DNA damage after melphalan treatment of the human myeloma cell line RPMI 8226. 191 98

The treatment of multiple myeloma is multidisciplinary and requires attention not only to the primary disease itself but to its secondary manifestations. Melphalan remains the single most effective oral chemotherapeutic drug used to treat multiple myeloma. A major problem with the oral administration of the drug is its variable bioavailability. The presence of an L-phenylalanine moiety in the structure of melphalan makes it likely that gastrointestinal absorption occurs through the normal amino acid transport mechanisms and that the presence of food influences the drug's uptake. Another factor that complicates the bioavailability of this agent is the fact that melphalan undergoes spontaneous hydrolysis at physiologic pH. One of the controversies in myeloma therapy is the continuing debate over the possible superiority of complex, multiagent chemotherapy regimens compared with single melphalan and prednisone or cyclophosphamide and prednisone. It does appear that response frequencies are considerably greater with combination chemotherapy than with standard oral melphalan and prednisone treatment. It is probable that both approaches--single-agent chemotherapy with melphalan and prednisone versus combination chemotherapy--can play a role in remission induction therapy. It may be appropriate to treat the patient with a low tumor burden with melphalan and prednisone and treat more aggressive myeloma patients with triple alkylator therapy or other combinations of chemotherapy agents. The most promising activity of interferon alfa-2b (rIFN alpha 2b) in induction of myeloma remission appears to occur when rIFN alpha 2b is combined with multiple alkylating agents. Analysis of clinical trials suggests that sequential use of rIFN alpha 2b with cytotoxic therapy may be more active than when IFN alpha 2b is given concomitantly with cytotoxic therapy. It may be most plausible to use rIFN alpha 2b in maintenance of remission of myeloma. In the laboratory, interferons have the capacity to modulate oncogene expression and to decrease both in vitro colony formation and the labeling index of myeloma cells. Further, it has been shown that interferon can reduce the capacity for self-renewal in myeloma-forming cells. The following concepts will be discussed: 1. There is promising evidence that rIFN alpha 2b may improve the frequency and quality of remission in multiple myeloma when administered in an alternating schedule. There is some evidence that rIFN alpha 2b, when combined with cytotoxic therapy and given concomitantly, may be less active.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:A review of the clinical studies of alpha-interferon in the management of multiple myeloma. 194 25

Multiple myeloma (MM) is characterized by an increased susceptibility to infections and to other malignancies. Selected related immune functions were studied. Spontaneous and interleukin-2-stimulated natural killer (NK) cell activities were normal in 19 patients with MM compared with 62 controls. In contrast, interferon-stimulated NK cells had a significantly lower increase in activity in MM than in controls. The normal improvement in lytic NK cell activity after addition of indomethacin to the mononuclear cell cultures (to inhibit prostaglandin-mediated suppression) was not observed in cultures from MM patients. As reported for other lymphoproliferative disorders, the levels of soluble interleukin-2 receptors in serum were significantly higher in MM (600 U/ml median value) compared with controls (317 U/ml median value), P less than 0.0001, and the concentration of interleukin-2 receptors was significantly correlated with the concentration of monoclonal immunoglobulin in serum. Blood monocyte chemotactic responsiveness was significantly lower in MM patients with both zymosan-activated serum and f-Met-Leu-Phe as cytotaxins, suggesting reduced ability to accumulate at inflammatory foci. In contrast, release of reactive oxygen radicals, believed to be associated with the killing ability of monocytes, was normal after in vitro stimulation.
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PMID:Immune dysfunction in multiple myeloma. Reduced natural killer cell activity and increased levels of soluble interleukin-2 receptors. 203 17

A patient with chronic renal failure was investigated after complaining of oral discomfort which was found to be due to macroglossia and generalized involvement of the oral soft tissues by amyloidosis. A search for multiple myeloma proved to be positive. She also had a previous history of Carpal-tunnel syndrome. Despite an initial good response to treatment with phenylalanine nitrogen mustard (melphalan hydrochloride), she finally succumbed to end-stage renal failure.
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PMID:Amyloidosis with oral involvement. Case report. 232 67

Amino acid substitutions specific for allotypic G3m(g5) marker were studied by sequence analysis of the C-terminal BrCN peptides of myeloma protein Ba [G3m(g5+)] and Bu [G3m(g5-)]. The results indicate that arginine and tyrosine at position 435 and 436 are responsible for the specificity. Two substitutions of IgG3 Bu [G3m(b1, b3)] and IgG3 Jir [G3m(b3,s,t)] [Matsumoto et al.: J. Immun. 131: 1865, 1983], in the same positions are arginine-phenylalanine and histidine-tyrosine, respectively. Affinity chromatographic data of modified IgG3 proteins show that the tyrosine residue at position 436 associated with phenylalanine at position 124 of protein A-B fragment plays a role in the interaction. The differences in the yields between IgG3s carrying various haplotypes on Protein A-Sepharose affinity chromatography [Ito et al.: Proc. Japan Acad. 56B: 226, 1980] are also explained through this chromatography and also by the configuration of the residues in tertiary structure [Deisenhofer: Biochemistry 20: 2361, 1980].
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PMID:Amino acid substitutions determining G3m(g5). 232 73

This study investigated the effect of platelet-activating factor (PAF), leukotriene B4 (LTB4) histamine and formyl-methionyl-leucyl-phenylalanine (FMLP) on immunoglobulin E (IgE) binding and IgE-dependent cytotoxicity of human normal density eosinophils. The binding of a native myeloma IgE to normal human eosinophils was measured by flow cytometry using a fluorescein-conjugated polyclonal anti-IgE antibody. Preincubation with PAF (optimal at 10(-7)M), but not lyso-PAF or FMLP, gave dose-dependent increases in IgE binding. PAF and LTB4 gave significant increases in IgE binding after 5 min preincubation (P less than 0.05); the effect was further enhanced at 30 min (P less than 0.01). This was further confirmed using the rosette assay where PAF and LTB4, but not lyso-PAF or FMLP, gave dose- and time-dependent increases in IgE eosinophil rosettes. Eosinophil cytotoxicity for schistosomula of Schistosoma mansoni, incubated with immune serum, was also significantly enhanced (P less than 0.01) by PAF in a dose-dependent fashion (optimal at 10(-8) M). Schistosomula coated with FPLC-purified IgE fractions were susceptible to killing by normal density eosinophils, and this was enhanced with PAF (10(-8)M), LTB4 (10(-7)M) and histamine (10(-5)M) but not with FMLP (10(-7)M) or lyso-PAF. IgE-dependent cytotoxicity was confirmed by the removal of contaminating IgG from IgE-rich fractions, and by the abolishment of IgE-dependent cytotoxicity after IgE adsorption. These results suggest that PAF (and to a lesser extent LTB4 and histamine) increase IgE binding, IgE-dependent adherence and cytotoxicity of normal human eosinophils. Although IgE receptors have not been identified, the data support current concepts that certain biological properties of eosinophils may be IgE associated.
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PMID:The effect of platelet-activating factor on IgE binding to, and IgE-dependent biological properties of, human eosinophils. 237 21

Hybridomas secreting monoclonal antibodies to Nippostrongylus brasiliensis antigens were generated by hybridization of IR983F myeloma cells with spleen cells from Lou/M/Wol rats infected with living third-stage larvae. Antibodies specific either for larval or worm antigens were identified by enzyme-linked immunosorbent assays with Nippostrongylus brasiliensis fragments, homogenates and secretions as antigens. The results demonstrate that all antibodies which recognized larval antigens (38 antibodies) also reacted with worm surfaces. Ten antibodies were specific only for worm antigens. Ten antibodies reacted with worm homogenate, three antibodies recognized components of worm secretion and 17 antibodies combined with acetylcholinesterase. The epitope specificity was investigated by the capacity of various glycosides, aminoacids, N-acetylneuraminic acid and phosphorylcholine to inhibit the binding to worm fragments. The analysis revealed that alpha-methylglucoside, alpha-methylmannoside, N-acetylglucosamine, N-acetylgalactosamine, fucose and the amino acids leucine, phenylalanine, tyrosine, serine, tryptophan did not combine with the antigen-binding sites of the antibodies. Proline, arginine and histidine, however, displayed inhibitory effects. With N-acetylneuraminic acid as inhibitor three groups of antibodies could be discriminated. At a concentration of 10-20 mM, phosphorylcholine was a potent inhibitor for all antibodies.
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PMID:Characterization of antigens of the nematode Nippostrongylus brasiliensis by monoclonal antibodies. 241 42

Amyloid subunit proteins related to the lambda IV subgroup of immunoglobulin light chains have not been previously reported. We have determined the amino acid sequence of an AL amyloid protein BAK and shown that it has the structure typical of lambda IV light chain proteins. This protein, which was isolated from the spleen of a patient with AL amyloidosis, has 111 residues in the variable domain and also includes the first tryptic peptide of the constant domain for a total of 130 residues. Comparison of the primary structure of this protein with the only other completely characterized lambda IV protein (SH) reveals that they are highly homologous with only one amino acid change in FR1, two changes in FR2, and one change in FR3. The CDR regions also show few changes, with only three in CDR1, one in CDR2, and five in CDR3. To test the hypothesis that the formation of AL amyloid is related to changes in the FR regions which could affect molecular aggregation, the structure of BAK was compared with the myeloma protein SH with respect to the presumed tertiary structure. Only limited amino acid substitution was found in the surface positions that might affect intradimer and interdimer aggregation. These included an isoleucine for leucine change at position 43 and phenylalanine for valine at 45, which may affect intradimer interaction and a change of histidine to asparagine at position 67.
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PMID:Amyloidosis related to a lambda IV immunoglobulin light chain protein. 249 77

The common acute lymphoblastic leukemia antigen (CALLA) is a 749-amino acid type II integral membrane protein expressed by most acute lymphoblastic leukemias, certain other lymphoid malignancies with an immature phenotype, and normal lymphoid progenitors. A computer search against the most recent GenBank release (no. 56) indicates that human CALLA cDNA encodes a protein nearly identical to the rat and rabbit neutral endopeptidase 24.11 ("enkephalinase;" EC 3.4.24.11). This zinc metalloendopeptidase, which has been shown to inactivate a variety of peptide hormones including enkephalin, chemotactic peptide, substance P, neurotensin, oxytocin, bradykinin, and angiotensins I and II, had not been identified in lymphoid cells. To determine whether CALLA cDNA derived from human acute lymphoblastic leukemia cells (Nalm-6 cell line) encodes functional neutral endopeptidase activity, we generated CALLA+ stable transfectants in the CALLA- murine myeloma cell line J558 and analyzed them for enzymatic activity in a fluorometric assay based upon cleavage of the substrate glutaryl-Ala-Ala-Phe 4-methoxy-2-naphthylamide at the Ala-Phe bond. Total lysates as well as whole-cell suspensions of the Nalm-6 line and of the CALLA+ transfectants, but not of the CALLA- J558 cells, possessed neutral endopeptidase activity. This enzymatic activity was associated with the cellular membrane fraction and was abrogated by the specific neutral endopeptidase inhibitor phosphoramidon. The unequivocal identification of CALLA as a functional neutral endopeptidase provides insight into its potential role in both normal and malignant lymphoid function.
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PMID:Common acute lymphoblastic leukemia antigen (CALLA) is active neutral endopeptidase 24.11 ("enkephalinase"): direct evidence by cDNA transfection analysis. 252 88

It has been shown that epitopes reactive with one group of rabbit antibodies to human fibrinopeptide A (hFPA, A alpha 1-16) are included in its COOH-terminal region (A alpha 7-16). It was further established that Asp-7, Phe-8, and Arg-16 contribute to immunoreactivity and that intact fibrinogen and hFPA-containing fragments react poorly with such antibodies. The purpose of this investigation was to prepare a synthetic peptide corresponding to A alpha 7-16 and use it for generation of FPA-specific monoclonal antibodies (MoAbs). Such probes would allow for development of assays that could measure hFPA directly in plasma. In our approach, an ovalbumin-conjugate of the hFPA homologue served as immunogen. Mouse spleen cells were fused with the immunoglobulin nonsecretor myeloma (P3X63Ag8.653). A hybridoma (8C2-5) has been isolated that secretes an antibody (MoAb/8C2-5) with the following characteristics: (a) IgG1, kappa isotype; (b) equilibrium dissociation constant of 1.5 +/- 0.2 x 10(7) L/mol with the [125I]-labeled N-tyrosyl derivative of hFPA [( 125I] Tyr-hFPA) as ligand; (c) reacts with hFPA and dog FPA (dFPA) but not with the des Arg (A alpha 1-15) or shorter peptides; (d) does not react with intact fibrinogen or A alpha-chain of human or dog origin; (e) does not react with the elastase-generated hFPA-containing peptide A alpha 1-21. Enzyme-based immunoassays (EIAs) have been developed for measuring plasma hFPA levels in the range 3 x 10(-8) to 5 x 10(-7) mol/L. Since it has already been shown by a number of investigators that hFPA levels in patients with overt defibrination fall into this range, we propose that the MoAb/8C2-5-based assays may serve as useful clinical tools in screening patients at risk of thrombosis. The 8C2-5 antibody may also be helpful in studies dealing with congenital dysfibrinogenemias, particularly in identifying heterozygous propositi with amino acid substitutions at any position within the A alpha 7-16 region. Finally, due to its cross-reactivity with dFPA, assays using this antibody should also be valuable in the canine experimental thrombosis model studies.
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PMID:Use of a synthetic homologue of human fibrinopeptide A for production of a monoclonal antibody specific for the free peptide. 275 51


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