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)

Microencapsulation of genetically engineered cells may have important applications as delivery systems for therapeutic proteins. However, optimization of the microcapsules with regard to mechanical stability, cell growth, and secretion of proteins is necessary in order to evaluate the future use of this delivery technology. We have explored the growth, survival, and secretion of therapeutic proteins from 293-EBNA cells producing endostatin (293 endo cells) and JJN3 myeloma cells producing hepatocyte growth factor (HGF) that have been embedded in various types of alginate capsules. Parameters that affect capsule integrity such as homogenous and inhomogenous gel cores and addition of an outer poly-L-lysine (PLL)-alginate coating were evaluated in relation to cell functions. When cells were encapsulated, the PLL layer was found to be absolutely required for the capsule integrity. The JJN3 and 293 endo cells displayed completely different growth and distribution patterns of live and dead cells within the microcapsules, as shown by 3D pictures reconstructed from images taken with confocal laser scanning microscopy (CLSM). Encapsulated JJN3 cells showed a bell-shaped growth and HGF secretion curve over a time period of 5 months. The 293 endo cells reached a plateau phase in growth after 23 days postencapsulation; however, after around 30 days a fraction of the microcapsules started to disintegrate. Microcapsule disintegration occurred with time irrespective of capsule and cell type, showing that alginate microcapsules possessing relatively high gel strength are not strong enough to keep proliferating cells within the microcapsules for prolonged time periods. Although this study shows that the stability of an alginate-based cell factory can be increased by a PLL-alginate coating, further improvement is necessary with regard to capsule integrity as well as controlling the cell growth before this technology can be used for therapy.
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PMID:Microencapsulation of cells producing therapeutic proteins: optimizing cell growth and secretion. 1216 72

Multiple myeloma (MM) is an incurable plasma cell malignancy. To investigate biochemical lesions associated with MM, we constructed an expression cDNA library from the OPM-2 human myeloma line. A highly transforming H-Ras mutant was identified by transfection analysis using NIH 3T3 cells. DNA sequencing demonstrated a single-point mutation at position 117 located in the guanine nucleotide-binding site resulting in a lysine-to-glutamic acid substitution. This mutant, H-Ras (K117E), was found to be constitutively activated in terms of GTP binding. We compared the biological effects of H-Ras (K117E) and H-Ras (G12V) in 32D murine hematopoietic progenitor cells. Whereas both Ras proteins are constitutively activated, 32D cells expressing H-Ras (G12V) are still dependent on IL-3 for survival and proliferation while cells carrying H-Ras (K117E) become IL-3 independent. Similar experiments conducted with the B9 line, an IL-6-dependent hybridoma, also demonstrated that B9/H-Ras (K117E) became IL-6-independent. Expression of H-Ras (K117E) in the human IL-6-dependent ANBL-6 myeloma line resulted in enhanced proliferation at suboptimal concentrations of IL-6. These observations suggest that H-Ras mutations at the binding site for the GTP nucleotide ring structure may also represent activating lesions and have additional biological effects when compared to previously described Ras mutants.
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PMID:An unusual H-Ras mutant isolated from a human multiple myeloma line leads to transformation and factor-independent cell growth. 1256 57

The origin of the myeloma protein found in mice bearing the plasma cell tumor X5563 has been investigated. Specific activity-time curves of the myeloma proteins isolated from the tumor and from the plasma of these animals were compared following intravenous injection of L-lysine-C(14). The results indicate that myeloma protein is synthesized in the plasma cell tumor.
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PMID:The formation of myeloma protein by a mouse plasma cell tumor. 1354 45

The objective was to identify some biochemical and physical properties for fusion protein IL6D24-PE40KDEL. Edman degradation, SDS-PAGE, peptide mass fingerprinting, Western blot and MTT were used for identification of the protein. The results showed that the sequence of N-terminus is Met-Ile-Asp-Lys-Gln-Ile, Met was added because of prokaryotic expression system; Western blot revealed that the purified protein could react with IL6 and PEA antibody. The purified protein IL6D24-PE40KDEL could kill the multiple myeloma cell lines U266 expressing high affinity IL6R, but it could not kill the cell lines CEM which not expressed IL6R; The molecular weight was 58.7 kD measuring by SDS-PAGE; peptide mass fingerprinting (PMF) confirmed that the construction of IL6D24-PE40KDEL was correct. A novel protein by Peptident database in EXPASY web site was identified. In conclusion, IL6D24-PE40KDEL is a new targeting protein with bioactivity of specific killing effect.
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PMID:[Biochemical and physical properties for a recombinant IL6 Pseudomonas exotoxin fusion protein IL6D24-PE40KDEL]. 1563 70

We have previously constructed an antibody-avidin (Av) fusion protein, anti-transferrin receptor (TfR) IgG3-Av, which can deliver biotinylated molecules to cells expressing the TfR. We now describe the use of the fusion protein for antibody-directed enzyme prodrug therapy (ADEPT). The 67 amino acid carboxyl-terminal domain (P67) of human propionyl-CoA carboxylase alpha subunit can be metabolically biotinylated at a fixed lysine residue. We genetically fused P67 to the carboxyl terminus of the yeast enzyme FCU1, a derivative of cytosine deaminase that can convert the non-toxic prodrug 5-fluorocytosine to the cytotoxic agent 5-fluorouracil. When produced in Escherichia coli cells overexpressing a biotin protein ligase, the FCU1-P67 fusion protein was efficiently mono-biotinylated. In the presence of 5-fluorocytosine, the biotinylated fusion protein conjugated to anti-rat TfR IgG3-Av efficiently killed rat Y3-Ag1.2.3 myeloma cells in vitro, while the same protein conjugated to an irrelevant (anti-dansyl) antibody fused to Av showed no cytotoxic effect. Efficient tumor cell killing was also observed when E. coli purine nucleoside phosphorylase was similarly targeted to the tumor cells in the presence of the prodrug 2-fluoro-2'-deoxyadenosine. These results suggest that when combined with P67-based biotinylation, anti-TfR IgG3-Av could serve as a universal delivery vector for targeted chemotherapy of cancer.
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PMID:A human biotin acceptor domain allows site-specific conjugation of an enzyme to an antibody-avidin fusion protein for targeted drug delivery. 1574 88

We established an IgA monoclonal antibody (mAb) against Shiga toxin 1 B subunits (Stx1B) from mouse nasal-associated lymphoid tissues (NALT) of BALB/c mice. We have developed an improved protocol in which cross-linked Stx1B is intranasally administered together with cholera toxin. Surface IgA-positive NALT lymphocytes from mice immunized in this manner were enriched and then fused with mouse myeloma cells to produce hybridoma cells. Hybridoma culture supernatants were examined to see if they contain IgA against Stx1B and if they can inhibit carbohydrate recognition by Stx1B. For the latter purpose, we prepared carbohydrate ligands in which globotriose is present on the poly-lysine backbone. The established IgA mAb exhibited saturable and dose-dependent binding to the immobilized Stx1B. Inversely, the binding of the carbohydrate ligands to the immobilized Stx1B was inhibited by the mAb pretreatment. Immunoblotting and SDS-PAGE analysis revealed dimeric IgA. The IgA mAb inhibited the binding of digoxigenin-conjugated Stx1B to natural ligands displayed on a Burkitt's lymphoma cell line, Ramos. These results suggested that surface IgA-positive B cells in the inductive sites of the mucosal immune system in the upper respiratory tract are a potent source for producing IgA mAb against protein antigens with weak immunogenicity such as Stx1B.
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PMID:Production of IgA monoclonal antibody against Shiga toxin binding subunits employing nasal-associated lymphoid tissue. 1599 15

DNA methylation is involved in malignancy and is seen, in progression, in more than 80% of all solid tumours. Methylation is one of the main physiological processes to induce silencing of gene expression. Much work has focused on the suppressor gene p16, which acts as a negative cell cycle regulator, while its inhibition (via methylation) will have a positive effect on the cell cycle advance. The methylation status of the p16 gene was analysed in a group of 159 patients. Methylation of the p16 gene was seen in 41/98 (42%) patients with multiple myeloma and 4/5 (80%) patients with primary plasma cell leukaemias. This data favours the importance of p16 methylation on cell cycle regulation in multiple myeloma. In a proposed mechanism, methylated CpG islands attract a protein, MeCP2, which recruits a transcriptional inhibitory complex that includes histone deacetylases. The deacetylated lysine tails of the histones closely interact with DNA, resulting in a transcriptionally repressed chromatin with inhibited gene transcription, providing potential synergy between demethylating drugs and histone deacetylase inhibitors. Based on the knowledge of epigenetic mechanisms, the potential application of demethylating agents should be further investigated. Multiple myeloma remains an incurable disease, so new treatment strategies are needed to improve the outcome of patients.
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PMID:Analysis of methylation pattern in multiple myeloma. 1616 69

Monoclonal antibodies (mAbs) against Tityus serrulatus venom were obtained by the fusion of SP2/0 murine myeloma cells and spleen cells from BALB/c mice immunized with a toxic fraction (TstFG50) of the Tityus venom (this G50 chromatography fraction represents most of the toxicity of the crude venom) conjugated to bovine serum albumin (BSA) with glutaraldehyde. From the initial screening of over 200 hybridoma fusion wells, a panel of 9 anti-TstFG50 secreting hybridomas was established. The capacity of mAbs to neutralize the TstFG50 toxic fraction toxic was determined by in vitro neutralization assays and by inhibition of the binding of 125I-TsVII to its site on rat brain synaptosomes. Only mAbTs1 neutralized 50% of the toxic effects produced by scorpion venom and showed 35% inhibition of the binding of 125I-TsVII at 10(-7) M. To map the epitope recognized by the protective mAbTs1, we prepared a comprehensive series of overlapping 15-mer synthetic peptides covering the amino acid sequences of the four Tityus proteins. MAbTs1 reacted with peptide 26 of TsIV (KKSKDKKADSGYSYW), peptide 30 of TsVII (KKGSSGYSAWPASYS) and peptide 31 of TsNTxP (KKGSSGYSAWPASYS). MAbTs1 was not reactive with any peptide from TsII. The N-terminal lysine residue from the epitope was found to be critical for mAbTs1 binding. The epitope was positioned on the available three-dimensional structure of TsVII together with the recently identified residues from the pharmacophore of beta-scorpion toxins. The neutralizing properties of mAbTs1 might be explained by spatial vicinity of epitope residues with pharmacophore residues.
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PMID:Molecular characterization of a neutralizing murine monoclonal antibody against Tityus serrulatus scorpion venom. 1616 49

Nuclear receptor-binding SET domain protein 1 (NSD1) prototype is a family of mammalian histone methyltransferases (NSD1, NSD2/MMSET/WHSC1, NSD3/WHSC1L1) that are essential in development and are mutated in human acute myeloid leukemia (AML), overgrowth syndromes, multiple myeloma and lung cancers. In AML, the recurring t(5;11)(q35;p15.5) translocation fuses NSD1 to nucleoporin-98 (NUP98). Here, we present the first characterization of the transforming properties and molecular mechanisms of NUP98-NSD1. We demonstrate that NUP98-NSD1 induces AML in vivo, sustains self-renewal of myeloid stem cells in vitro, and enforces expression of the HoxA7, HoxA9, HoxA10 and Meis1 proto-oncogenes. Mechanistically, NUP98-NSD1 binds genomic elements adjacent to HoxA7 and HoxA9, maintains histone H3 Lys 36 (H3K36) methylation and histone acetylation, and prevents EZH2-mediated transcriptional repression of the Hox-A locus during differentiation. Deletion of the NUP98 FG-repeat domain, or mutations in NSD1 that inactivate the H3K36 methyltransferase activity or that prevent binding of NUP98-NSD1 to the Hox-A locus precluded both Hox-A gene activation and myeloid progenitor immortalization. We propose that NUP98-NSD1 prevents EZH2-mediated repression of Hox-A locus genes by colocalizing H3K36 methylation and histone acetylation at regulatory DNA elements. This report is the first to link deregulated H3K36 methylation to tumorigenesis and to link NSD1 to transcriptional regulation of the Hox-A locus.
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PMID:NUP98-NSD1 links H3K36 methylation to Hox-A gene activation and leukaemogenesis. 1758 99

MMSET, identified by its fusion to the IgH locus in t(4;14)-associated multiple myeloma, possesses domains found within chromatin regulators, including the SET domain. MMSET protein is overexpressed and highly associated with chromatin in myeloma cell lines carrying t(4;14). MMSET possesses methyltransferase activity for core histone H3 lysine 4 and histone 4 lysine 20, whereas MMSET made in cells only modified H4. Segments of MMSET fused to the Gal4 DNA binding domain repressed transcription of a chromatin-embedded Gal4 reporter gene. MMSET-mediated repression was associated with increased H4K20 methylation gene and loss of histone acetylation. Consistent with this repressive activity, MMSET could form a complex with HDAC1 and HDAC2, mSin3a, and the histone demethylase LSD1, suggesting that it is a component of corepressor complexes. Furthermore, MMSET coexpression enhances HDAC1- and HDAC2-mediated repression in transcriptional reporter assays. Finally, shRNA-mediated knockdown of MMSET compromised viability of a myeloma cell line, suggesting a biologic role for the protein in malignant cell growth. Collectively, these data suggest that, by acting directly as a modifier of chromatin as well as through binding of other chromatin-modifying enzymes, MMSET influences gene expression and potentially acts as a pathogenic agent in multiple myeloma.
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PMID:The MMSET protein is a histone methyltransferase with characteristics of a transcriptional corepressor. 1815 91


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