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)

Experiments to determine the hydrolysis and protein binding of melphalan (L-phenylalanine mustard, L-PAM) were carried out in vitro for therapeutic concentration of the drug: the decrease in L-PAM concentration in plasma and whole blood during 24 h incubation at 37 degrees C was only 5% due to hydrolysis. Serum protein binding was about 90%, whereby 60% and 20% of this binding was due to interactions with albumin and acid alpha 1-glycoprotein, respectively. Immunoglobulins did not participate in the binding of L-PAM. The covalently bound part of L-PAM in serum was 30% in the concentration range of 1-30 micrograms/ml. The binding of dihydroxymelphalan (DOH) in serum did not exceed 20%. Glucocorticoids used in combination with L-PAM for treating multiple myeloma did not influence its protein binding. Our study with 35 sera from 15 patients with multiple myeloma shows that high levels of paraproteins do not increase but may decrease the binding of L-PAM, resulting in an elevated concentration of free drug.
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PMID:Relevance of the hydrolysis and protein binding of melphalan to the treatment of multiple myeloma. 291 May 15

A new method for the measurement of DNA damage in individual cells treated with alkylating agents is described. The method is based on the binding of anti-DNA monoclonal antibody to DNA in situ. Monoclonal antibody F7-26 was obtained by fusion of mouse myeloma cells with spleen cells isolated from a mouse immunized with DNA treated by nitrogen mustard (HN2). Binding of antibody was evaluated by flow cytometry with indirect immunofluorescence. No binding of antibody to DNA in non-treated HeLa S3 cells was detected. Treatment of cells with HN2 or L-phenylalanine mustard induced binding of antibody to DNA in situ. Binding of antibody was observed after treating cells with doses of drugs which reduced the surviving fraction below 20%. Intensity of binding increased in proportion to the drug dose. Two-parameter analysis for the antibody binding and DNA content showed no binding of antibody to replicating DNA in control cells. In HN2-treated cells a cell subset with the lowest antibody binding was observed among cells in G1 phase. Binding of antibody to DNA in HN2-treated cells was eliminated by single-strand (ss) specific S1 nuclease. In competition assay, antibody was inhibited by thermally denatured DNA, but not by native double-stranded (ds) DNA, RNA, nucleosides and deoxyribohomopolymers. Binding of monoclonal antibody specific for the determinants expressed on ssDNA to the cells treated with alkylating agents may be attributed to local DNA denaturation. Potentiation of L-phenylalanine mustard cytotoxicity by buthionine sulfoximine or hyperthermia was accompanied by increased antibody binding to cellular DNA. Immunoreactivity of cells with the monoclonal antibody F7-26 may be a useful probe for the assessment of cell damage induced by alkylating agents, especially in heterogeneous cell populations.
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PMID:Detection of DNA damage in individual cells by flow cytometric analysis using anti-DNA monoclonal antibody. 303 52

Melphalan (L-phenylalanine mustard) is a bifunctional alkylating agent that is commonly administered orally to treat a wide variety of malignancies, including cancers of the breast and ovary, as well as multiple myeloma. Although commercially available in Europe and Canada, intravenous (IV) melphalan remains investigational in the United States. The role of IV melphalan in cancer chemotherapy is not well defined, despite its manageable toxicity and higher and more predictable blood levels following IV administration compared with oral administration. In addition, unlike oral melphalan, an extensive phase I evaluation of IV melphalan has not been undertaken. At lower doses (eg, 30 to 70 mg/m2), both as a single agent and in combination, the activity of IV melphalan has been evaluated in only a limited number of diseases. However, striking activity has been observed in previously untreated patients with rhabdomyosarcoma, a disease not generally considered responsive to alkylating agents. When administered at high doses (greater than 140 mg/m2) requiring bone marrow reinfusion, melphalan effects a high response rate (but no improvement in survival) in a variety of nonhematologic tumor types, including resistant tumors such as melanoma and colon carcinoma. In contrast, in poor-prognosis patients with non-Hodgkin's lymphoma, Hodgkin's disease, multiple myeloma, or neuroblastoma, high-dose melphalan-containing regimens have yielded both high response rates and improved survival, despite considerable toxicity. Additional clinical trials will be necessary to define the spectrum of activity of lower doses of IV melphalan and to define subgroups of patients most likely to benefit from high-dose melphalan.
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PMID:The systemic administration of intravenous melphalan. 305 5

In an attempt to understand the relationship of amino acid sequence to the formation of primary or multiple myeloma-related amyloid (AL amyloid), we have determined the complete amino acid sequence of amyloid protein BAN. This protein belongs to the kappa I immunoglobulin light chain subgroup and has a polypeptide chain length of 126 amino acids. It encompasses the entire variable region, the joining segment and the first tryptic peptide of the constant region. This protein has two unique features. First, the molecule is glycosylated. At position 61 the usual arginine residue has been replaced by an asparagine with the generation of the signal sequence Asn-Phe-Thr, to which a glucosamine-containing carbohydrate unit is attached. Secondly, the protein is not monoclonal but consists of two chains which have the same variable region but different J-segments. Comparison of the BAN sequence with other amyloid and nonamyloid kappa I proteins reveals a systematic difference between the two groups. In the amyloid proteins, several hydrophilic framework residues have been replaced by hydrophobic residues. These substitutions may provide the nucleation sites for self-aggregation and fibril formation.
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PMID:Polymorphism in a kappa I primary (AL) amyloid protein (BAN). 308 40

Plasma fibronectin has been implicated as an important determinant of neutrophil adhesion to plastic surfaces. Using a monoclonal antifibronectin antibody, we examined the role of fibronectin (Fn) in chemotactic factor-mediated neutrophil attachment to various substrates. The chemotactic factor N-formyl-methionyl-leucyl-phenylalanine (FMLP) significantly enhanced neutrophil adherence to multiple substrates including gelatin, gelatin coated with Fc fragments of human IgG or Fn, plastic alone, plastic coated with Fc fragments, or purified plasma Fn. An IgM monoclonal antibody to plasma Fn significantly inhibited FMLP-stimulated neutrophil attachment to gelatin, gelatin-Fc, gelatin-Fn, plastic, plastic-Fc, and plastic-Fn substrates when compared with the parent line myeloma supernatant or an irrelevant IgM monoclonal antibody. No reduction in FMLP-stimulated adherence to the gelatin-plasma or plastic-plasma substrates occurred in the presence of antibody. Anti-Fn antibody reduced FMLP-stimulated adhesion only when present during the entire assay; incubation of cells or substrates alone with antibody, followed by removal of excess antibody before addition of stimulus incubation, failed to alter adherence. These data suggest that neutrophil-derived Fn may play a role in chemotactic factor-induced neutrophil adherence to both collagenous and noncollagenous substrates. Further support for the hypothesis was suggested by the demonstration of release of immunoreactive Fn into incubation media from FMLP-stimulated neutrophils.
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PMID:Fibronectin mediates chemotactic factor-stimulated neutrophil substrate adhesion. 315 17

To mimic the sequence spanning the primary site (the Lys158-Ile159 bond) cleaved by plasmin in its conversion of single-chain urokinase plasminogen activator (scuPA) to urokinase, we synthesized the peptide Cys(Acm)-Leu-Arg-Pro-Arg-Phe-Lys-Ile-Ile-Gly-Gly-Glu-Phe-Cys [Cys(Acm)scuPA(153-164)Cys]. Immunization of A/J mice with the Cys(Acm)scuPA(153-164)Cys peptide linked to hemocyanin, followed by somatic cell fusion with a myeloma cell line (SP2/0), yielded a monoclonal antibody (SCOOP1) that bound to single-chain urokinase but not to urokinase or plasmin-treated single-chain urokinase. SCOOP1 could discriminate between single-chain urokinase and urokinase by greater than three orders of magnitude. In a radioimmunoassay, Cys(Acm)scuPA(153-164)Cys completely inhibited SCOOP1 binding to single-chain urokinase, whereas an equimolar mixture of two heptapeptides comprising the amino terminal [Cys-scuPA(153-158)] and carboxy terminal [scuPA(159-164)Cys)] halves of the cleavage site peptide did not. Thus the epitope recognized by SCOOP1 includes the Lys158-Ile159 peptide bond.
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PMID:A sequence-dependent monoclonal antibody specific for single-chain urokinase. 336 58

Previous work has shown that IgG rheumatoid factors (RF) bind to the C gamma 2-C gamma 3 interface region of human IgG in the same area that binds staphylococcal protein A (SPA). Group A, C, and G strains of Streptococci possess Fc receptors that bind to IgG but not to fragments containing only the C gamma 2 or C gamma 3 domains. This work describes the binding site location on human IgG for the binding of the isolated Fc receptor from the T15 strain of a Group A streptococcus and its relationship to the site that binds SPA and the IgG RF. The isolated T15 Fc receptor (T15) with a molecular mass of 29.5 kD inhibited the binding of IgG RF to IgG. The binding of T15 itself to IgG was strongly inhibited by SPA (42.0 kD) and its monovalent fragment D (7 kD). Human IgG fragments consisting of the C gamma 3 domains did not inhibit the binding of T15 to IgG, whereas those with both domains were effective inhibitors. T15 did not bind to rabbit IgG fragments consisting of either the C gamma 2 or C gamma 3 domains, but did bind to those with both domains. An IgG3 myeloma protein was a poor inhibitor and has been shown to bind poorly to the IgG RF. Most IgG3 myeloma proteins did not bind to SPA. The substitution of Arg and Phe for His 435 and Tyr 436 is responsible for the poor binding of IgG3 to SPA and to the IgG RF. Chemical modification of His or Tyr on IgG reduced its ability to inhibit the binding of T15 to IgG. Reversal of the chemical modifications with hydroxylamine resulted in near complete restoration of inhibitory capacity. This information, collectively, coupled with the known positions in space of the His and Tyr residues in the C gamma 2-C gamma 3 interface region, verified that both His 435 and Tyr 436, and possibly His 310 and 433, are involved. These residues are also involved in binding SPA and the IgG RF. These data therefore indicate that the T15 Group A Streptococcal Fc receptor binds to the same location on the Fc of IgG as SPA and the IgG RF. The biologic relevance of these similarities between bacterial cell wall Fc receptors and IgG RF are not yet apparent, but suggest that RF could bear the internal image of these bacterial structures.
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PMID:T15 group A streptococcal Fc receptor binds to the same location on IgG as staphylococcal protein A and IgG rheumatoid factors. 354 19

Melphalan (MEL) is an aromatic alkylating agent which is useful for the treatment of a number of human cancers, including myeloma and ovarian cancer. However, like most cytotoxic drugs, MEL has side effects, due to its nonspecific effects on all or most cells. To overcome these nonspecific effects N-acetyl melphalan (N-AcMEL) was synthesized and found to be 75 times less toxic to tumor cells in vitro. However, when N-AcMEL was conjugated to monoclonal antibodies (MoAbs) to form N-AcMEL-MoAb conjugates the cytotoxic effect of MEL was restored, but with a difference in that the MEL could only act on cells which bound antibody. It was shown that, for N-AcMEL-MoAb conjugates, the N-AcMEL entered cells via the MoAb, by endocytosis, and not by the phenylalanine amino acid transport system. In addition, N-AcMEL-MoAb conjugates more effectively erradicated tumors in vivo than does free MEL or N-AcMEL. The N-AcMEL-MoAb conjugates therefore have high specific activity both in vitro and in vivo and a markedly reduced nonspecific toxicity, as N-AcMEL is relatively nontoxic to cells unless conveyed there by MoAb. In these respects the study offers a new approach to the use of chemotherapeutic agents in patients with cancer.
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PMID:Selective enhancement of antitumor activity of N-acetyl melphalan upon conjugation to monoclonal antibodies. 379 Dec 21

The amino-acid sequence Phe-Tyr-Met-Glu is unique to phosphorylcholine (PC)-binding antibodies. It occurs in the first complementarity-determining region (CDR1) of the immunoglobulin heavy chains in 89% of all the anti-PC myeloma and hybridoma proteins but is not present in 490 other immunoglobulin heavy chains, 854 light chains or in 2,260 other unrelated proteins. This unique tetrapeptide therefore seems to be involved in PC binding. Here we compare the effectiveness of Phe-Tyr-Met-Glu and other structurally related peptides in inhibiting the binding of PC to PC-binding proteins McPC603 and HOPC8. We also test a surface-simulation peptide that was constructed to mimic the combining site of McPC603. Our data suggest that all these peptides inhibit the binding of PC to PC-binding proteins non-specifically and we show by computer modelling that the surface-simulation peptide does not duplicate the combining site of McPC603.
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PMID:Inhibition of phosphorylcholine binding to antibodies using synthetic peptides. 380 74

Glycopeptides have been isolated from tryptic digests of kappa-type light chains separated from human myeloma proteins obtained from the serum of two patients, Car and Rai. The glycopeptides are derived from the variable region of the chain in both cases, but from different sections. On the basis of homology it is deduced that glycopeptide from Car, kappaI type, is derived from position 25-31 whereas that from Rai, kappaII type, is from position 62-77, their sequences being respectively Ala-Ser-Gln-Asn-Ile-Ser and Phe-Ser-Gly-Ser-Gly-Ser-Gly(Thr,Asp)Phe-Thr-Leu-Asx-Ile-Ser-Arg. The significance of the results is discussed in connexion with the nature of the attachment site of carbohydrate to protein.
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PMID:Glycopeptides from human kappa-chains. 511 28


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