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 complete amino acid sequence of a protein, acid soluble fraction, (ASF) which constitutes up to 50% of amyloid fibrils from a patient with familial Mediterranean fever has been obtained. Partial amino acid sequences of three other proteins from patients with secondary amyloidosis were identical in the regions studied except for an alanine-valine interchange in one. The ASF contains no cysteine, does not resemble any known immunoglobulin, and has not been detected as yet in myeloma-associated amyloid.
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PMID:The amino acid sequence of a major nonimmunoglobulin component of some amyloid fibrils. 505 69

The authors established the amino acid substitutions determining G3m(s) and G3m(t) specificities, which characterize Mongoloid populations, by sequence analysis of the Fc region of a myeloma protein (Jir). By comparing the amino acid sequences of the IgG3 (Jir) and the other IgG subclasses analyzed to date, it was found that G3m(s) was an isoallotype specified by an amino acid substitution at position 435; i.e., whereas the subclasses IgG1, IgG2, and IgG4 had histidine in common, G3m(s-) had arginine in this position. This was also confirmed by the observation that the Fc fragment in question bound to protein A. It was also established that the amino acid at position 379 of G3m(t-) IgG3 and the other subclasses was valine, whereas methionine in this position was specific for G3m(t+). In addition, the amino acids at position 339 of G3m(u-) IgG3 Jir was threonine, and at position 296 of G3m(g-) IgG3 Jir was tyrosine. These findings are not in accord with the hitherto postulated relations of alanine and phenylalanine to G3m(u-) and G3m(g-), respectively. Finally, this study showed that a large number of substitutions occurred at positions 384 through 389, which suggests that many specificities of the G3m(b) group occur on IgG3 proteins.
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PMID:Structural studies of a human gamma 3 myeloma protein (Jir) bearing the allotypic marker Gm(st). 641 81

The complete amino acid sequence of the variable region of Bence-Jones protein Mev. from a patient suffering from multiple myeloma and generalized amyloidosis is presented. The amino acid sequence of the Bence-Jones protein Mev. is related to other human kappa-immunoglobulin L-chains of subgroup I. With valine established in Position 191 of the constant region, it is of the Inv (3) allotype. Two types of the Bence-Jones protein Mev. were found, one beginning with the typical N-terminal aspartic acid, and another lacking the N-terminal tripeptide and commencing with methionine in Position 4. A unique insertion of glutamic acid after Position 95 was found in the Bence-Jones protein. This is the position where the V- and J-gene segments join. The J-region of Bence-Jones protein Mev. exhibits some marked differences to the five J-regions recently established by nucleic acid sequencing. This suggests, that there must be considerable polymorphism in human kappa-J-genes. The amyloid fibril protein from the same patient (A Mev.) has also been sequenced up to Position 27. It was found to be identical to the sequence of Bence-Jones protein Mev. commencing with aspartic acid. The molecular mass of the amyloid fibril protein was found to be between 11 000 and 12 000 Da as estimated by gelfiltration and dodecyl sulfate-polyacrylamide electrophoresis.
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PMID:Primary structure of the variable part of an amyloidogenic Bence-Jones Protein (Mev.). An unusual insertion in the third hypervariable region of a human kappa-immunoglobulin light chain. 681 13

The enantiomeric separations of D,L-amino acids derivatized with fluorogenic reagents, 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), 4-(N,N-dimethylaminosulphonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) and 4-aminosulphonyl-7-fluoro-2,1,3-benzoxadiazole (ABD-F) by high-performance liquid chromatography (HPLC) on various Pirkle type chiral stationary phases (CSPs, Sumichiral OA series) with citric acid in methanol as a mobile phase were studied. Since the least retention and no separation was observed for the derivatives of racemic phenylalanine methyl-ester, -amide and a drug without an alpha-carboxyl group, the carboxylic acid group of the amino acid derivatives seemed to contribute to the enantioselective fixation of the derivatives through hydrogen bonding on the N-acyl-amino acid amide moiety of the CSP. The enantioselective retention of the derivatives was attained through the (S) or (R) configuration of valine, phenylglycine, naphthylglycine, naphthylethylamine or the tert-leucine moiety in the CSP. The 2,1,3-benzoxadiazole (benzofurazan) moiety in the derivatives helps the effective fixation of the derivatives through a pi-pi interaction with an aromatic moiety such as a 3,5-dinitrophenyl or naphthyl group in the Pirkle type chiral stationary phases. D-Amino acids in biological samples were easily determined utilizing the present derivatization with NBD-F, enantiomeric separation and fluorometric detection (530 nm em/470 nm ex) following deproteinization of biological samples (serum or brain homogenate) with methanol and centrifugation. The applications of the method were clearly demonstrated by the following results; D-Ala was detected in sera of healthy volunteers at a level of 0.48-3.10 microM. D-Lys was found in the serum of a patient with myeloma and requiring renal dialysis, and D-Ser was found in rat and bovine cerebrum. Peak identification was performed by use of different types of stationary phases especially those bearing the opposite configuration to that of the chiral centre.
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PMID:Enantiomeric separation and sensitive determination of D,L-amino acids derivatized with fluorogenic benzofurazan reagents on Pirkle type stationary phases. 773 28

Of 5 multiple myeloma patients with hyperammonemia, autopsy was performed in 4 patients, while amino acid metabolism was examined in 3 patients. As a result they were classified into the following 3 types; A, liver dysfunction and severe liver infiltration of myeloma cells. B, severe liver infiltration without liver dysfunction. C, Neither liver dysfunction nor severe liver infiltration. In one type A patient, isoleucine decreased. In two patients without liver dysfunction (one type C patient and another patient in whom autopsy was not performed) valine, leucine and isoleucine decreased, and tyrosine decreased slightly. The Fischer ratio decreased in these 2 patients, while it decreased slightly in a type A patient. Clinically, in 4 patients hyperammonemia was observed during periods of poor general condition and when refractory to chemotherapy. In an aggressive type case, consciousness disturbance was developed rapidly and multiple myeloma was diagnosed. In all patients, consciousness disturbance was noted. Hyperammonemia might have been caused by hepatic failure or systemic-portal shunt in patients with liver infiltration. In those without liver infiltration, it was suggested that hyperammonemia was caused by myeloma related humoral factors that influence amino acid metabolism.
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PMID:[Clinicopathological study of multiple myeloma associated with hyperammonemia]. 949 50

Germline mutations of LKB1/Peutz-Jeghers syndrome gene predispose carriers to hamartomatous polyposis of the gastrointestinal tract as well as to cancer of different organ systems. Although Peutz-Jeghers syndrome patients frequently present with neoplasms of the colon, stomach, small intestine, pancreas, breast, ovaries, and cervix, somatic mutations appear to be rare in the sporadic tumor types thus far studied (colorectal, gastric, testicular, and breast cancers). To evaluate whether somatic mutations of LKB1 contribute to the tumorigenesis of yet unstudied tumor types, we screened 14 cell lines and 129 tumor specimens from different cancers for a genetic defect in LKB1. Six melanoma and eight myeloma cell lines were scrutinized for LKB1 somatic mutations by genomic sequencing. No changes were found in the coding LKB1 sequence and exon/intron boundaries. Next, we analyzed 12 pancreatic, 8 gastric, 12 ovarian granulosa cell, 26 cervical, 28 lung, 24 soft tissue, and 19 renal tumors by single-strand conformational polymorphism analysis. Three changes in LKB1 coding nucleotide sequence were identified. One base pair deletion at A957 and G958 substitution by T occurred in a cervical adenocarcinoma sample, resulting in a frameshift and premature stop codon at position 335. Substitution of A581 by T occurred in a lung adenocarcinoma sample, resulting in the change of aspartic acid at position 194 to valine. A loss of another allele was detected in this sample. One silent change, C1257T, was found in a pancreatic carcinoma sample. The changes were not present in the matched normal tissue DNA samples. Our results suggest that mutational inactivation of LKB1 is a rare event in most sporadic tumor types.
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PMID:LKB1 somatic mutations in sporadic tumors. 1007 45

Sapphyrins are pentapyrrolic, metal-free, expanded porphyrins. In the present study, the activity of sapphyrins as anticancer agents in hematopoietic-derived tumor cells was explored. It was found that a dihydroxylated water-soluble sapphyrin derivative (PCI-2000) is a potent inducer of apoptosis in a wide variety of tumor cell lines including lymphoma (Ramos, DHL-4, and HF-1), leukemia (Jurkat and HL-60), and myeloma (8226/S, 1-310, C2E3, and 1-414). PCI-2000 triggers an apoptotic pathway in these tumor cells as shown by release of cytochrome c from mitochondria; activation of caspases 9, 8, and 3; cleavage of the caspase substrate poly(ADP-ribose) polymerase; and Annexin V binding. Apoptosis can be partially inhibited by overexpression of the antiapoptotic protein Bcl-2 or treatment with benzyloxycarbonyl-valine-alanine-aspartic acid-fluoromethylketone, a cell-permeable caspase inhibitor. Both PCI-2000 and PCI-2010, a tetrahydroxy bis-carbamate derivative of PCI-2000, result in increased levels of phosphorylated p38 mitogen-activated protein kinase. Inhibition of p38 mitogen-activated protein kinase phosphorylation resulted in a synergistic increase of PCI-2000 cytotoxicity. PCI-2010 showed less toxicity in mice than PCI-2000 and was active in slowing the growth of Ramos and HL-60 tumor xenografts in nude mice. These results provide preclinical rationale for the further study of sapphyrins for potential use in the treatment of hematopoietic-derived tumors.
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PMID:Sapphyrins induce apoptosis in hematopoietic tumor-derived cell lines and show in vivo antitumor activity. 1595 54

A 76-year-old Afro-Caribbean man presenting with heart failure was diagnosed with isolated cardiac amyloid. He had evidence of myeloma on bone marrow biopsy suggesting AL amyloid, the commonest type of systemic amyloidosis, as the underlying cause. He had no other myeloma-related organ damage. However, endocardial biopsy revealed amyloid fibrils composed of transthyretin and genetic typing established heterozygozity for the valine to isoleucine mutation at position 122 (Val122Ile). The diagnosis was therefore hereditary systemic amyloidosis as a result of a genetic transthyretin variant (ATTR) causing cardiac amyloidosis and coexistent asymptomatic myeloma. This requires symptomatic treatment of heart failure only. This article discusses a rare cause of heart failure and uses this case to illustrate that histological confirmation of the amyloid-causing protein is essential. Mistaken assumption of AL amyloid could have resulted in inappropriate cytotoxic therapy targeting the plasma cell clone.
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PMID:Coexistent asymptomatic myeloma and hereditary cardiac amyloidosis: an unusual case of heart failure. 2208 4

Fc receptor-like 5 (FcRL5/FcRH5/IRTA2/CD307) is a surface protein expressed selectively on B cells and plasma cells. We found that FcRL5 was expressed at elevated levels on the surface of plasma cells from the bone marrow of patients diagnosed with multiple myeloma. This prevalence in multiple myeloma and narrow pattern of normal expression indicate that FcRL5 could be a target for antibody-based therapies for multiple myeloma, particularly antibody-drug conjugates (ADC), potent cytotoxic drugs linked to antibodies via specialized chemical linkers, where limited expression on normal tissues is a key component to their safety. We found that FcRL5 is internalized upon antibody binding, indicating that ADCs to FcRL5 could be effective. Indeed, we found that FcRL5 ADCs were efficacious in vitro and in vivo but the unconjugated antibody was not. The two most effective consisted of our anti-FcRL5 antibody conjugated through cysteines to monomethylauristatin E (MMAE) by a maleimidocaproyl-valine-citrulline-p-aminobenzyloxycarbonyl (MC-vcPAB) linker (anti-FcRL5-MC-vcPAB-MMAE) or conjugated via lysines to the maytansinoid DM4 through a disulfide linker (anti-FcRL5-SPDB-DM4). These two ADCs were highly effective in vivo in combination with bortezomib or lenalidomide, drugs in use for the treatment of multiple myeloma. These data show that the FcRL5 ADCs described herein show promise as an effective treatment for multiple myeloma.
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PMID:FcRL5 as a target of antibody-drug conjugates for the treatment of multiple myeloma. 2280 77

Inhibitors of the mechanistic target of rapamycin (mTOR) hold promise for treatment of hematological malignancies. Analogs of the allosteric mTOR inhibitor rapamycin are approved for mantle cell lymphoma but have limited efficacy in other blood cancers. ATP-competitive "active-site" mTOR inhibitors produce more complete mTOR inhibition and are more effective than rapamycin in preclinical models of leukemia, lymphoma and multiple myeloma. In parallel to clinical trials of active-site mTOR inhibitors, it will be important to identify resistance mechanisms that might limit drug efficacy in certain patients. From a panel of diffuse large B-cell lymphoma cell lines, we found that the VAL cell line is particularly resistant to apoptosis in the presence of active-site mTOR inhibitors. Mechanistic investigation showed that VAL does not express eukaryotic initiation factor 4E-binding protein-1 (4EBP1), a key negative regulator of translation controlled by mTOR. Although VAL cells express the related protein 4EBP2, mTOR inhibitor treatment fails to displace eukaryotic initiation factor 4G from the mRNA cap-binding complex. Knockdown of eukaryotic initiation factor 4E, or re-expression of 4EBP1, sensitizes cells to apoptosis when treated with active-site mTOR inhibitors. These findings provide a naturally occurring example of 4EBP deficiency driving lymphoma cell resistance to active-site mTOR inhibitors.
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PMID:Resistance to mTOR kinase inhibitors in lymphoma cells lacking 4EBP1. 2458 20


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