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)

Hybridoma cells usually grow to fairly low cell densities in batch cultures (1-3 x 10(6) cells/ml). The reason for this is either that essential nutritional components of the medium are consumed, or that the cells produce some kind of inhibitory or toxic metabolite. This investigation presents evidence for the latter. Spent medium from cultures of hybridoma cells did not support growth of cells at lower cell densities (1-3 x 10(5) cells/ml). The ability to support cell growth could not be restored by adding additional serum, energy sources (glucose, pyruvate) or L-glutamine. Furthermore, the consumption of amino acids could not account for this growth inhibition. On the contrary, the spent medium contained a substance that inhibited cell growth. This substance or metabolite was found in a fraction eluted from a gel filtration column when spent medium was applied to the column. This substance was found in the spent medium from all hybridoma and myeloma cell lines that were tested. The molecular weight of the substance was about 5 kD. Spent medium from two hybridoma cell lines also contained a substance that was eluted in the same fraction as albumin (67 kD). It is likely that this (or these) substance(s) is responsible for the growth limitation in hybridoma cell cultures.
Cytotechnology 1991 Sep
PMID:Growth limitation in hybridoma cell cultures: the role of inhibitory or toxic metabolites. 136 98

The ABPC 48 myeloma protein and the 3-14-9 mAb derive their V region genes from the same VH and V kappa gene families. They also share a cross-reactive idiotope defined by the anti-Id mAb IDA 10. Whereas ABPC 48 is specific for bacterial levan, 3-14-9 showed a significant Ag-binding activity to aminophenyl-beta-N-acetylglucosaminide (AZO). In order to define the molecular basis of idiotope expression and Ag-binding activity, we have cloned the genes encoding the 3-14-9 H and L chain V region genes, generated antibodies that carry mutations within the L chain genes, by site-directed mutagenesis, and investigated the effects of those mutations with respect to IDA 10 idiotope expression and binding to AZO. Our findings show that, whereas expression of the IDA 10-defined idiotope requires association of both the H and L chains, a single change (glycine to phenylalanine) at position 91 in the third complementarity-determining region of the L chain abolished both idiotope expression and Ag-binding activity. In addition, a L chain change of alanine to threonine at position 25 allowed idiotope expression to some extent but significantly reduced binding activity to AZO. These data suggest that a single amino acid change can play a crucial role in the functional activity and structural integrity of antibodies.
J Immunol 1992 Sep 01
PMID:A single amino acid mutation in CDR3 of the 3-14-9 L chain abolished expression of the IDA 10-defined idiotope and antigen binding. 138 May 35

We have examined the effects of the nitrosoureas, streptozotocin (STZ) and 1,3-bis(chloroethyl)-1-nitrosourea (BCNU), on a human multiple myeloma cell line, RPMI 8226, and its drug-resistant variants. Cell lines selected for doxorubicin (DOX) resistance alone displayed a STZ and BCNU cytotoxicity profile similar to that of the parent cell line. In contrast, two of the drug-resistant variants selected with DOX plus verapamil, an agent which inhibits P-glycoprotein-mediated multidrug resistance, displayed a collateral sensitivity to STZ and BCNU. Verapamil was included in the selection protocol because it has been shown to inhibit the P-glycoprotein-mediated multidrug resistance phenotype and is now in clinical trials as a chemosensitizing agent. The collateral sensitivity to these nitrosoureas seen in the DOX plus verapamil-selected cell lines is due to the functional loss of a DNA repair molecule, O6-Methylguanine DNA methyltransferase (MGMT). The functional loss of MGMT is secondary to the loss of MGMT gene expression. The loss of MGMT gene expression is not due to loss or gross rearrangement of the MGMT-coding region. If this selection pressure applied in vitro reflects the in vivo situation, then new chemotherapeutic strategies may be devised to exploit this phenomenon. These cell lines will serve as useful models for delineating mechanisms which govern MGMT expression.
Cancer Res 1992 Sep 15
PMID:Collateral sensitivity to nitrosoureas in multidrug-resistant cells selected with verapamil. 138 86

The latent precursor of matrilysin (EC 3.4.24.23; punctuated metalloproteinase (PUMP) was purified from transfected mouse myeloma cell conditioned medium and was found to contain one zinc atom per molecule which was essential for catalytic activity. Promatrilysin could be activated to the same specific activity by (4-aminophenyl)mercuric acetate, trypsin, and incubation at elevated temperatures (heat activation). Active matrilysin hydrolyzed the fluorescent substrate 2,4-dinitrophenyl-Pro-Leu-Gly-Leu-Trp-Ala-D-Arg-NH2 at the Gly-Leu bond with a maximum value for kcat/Km of 1.3 x 10(4) M-1 s-1 at the pH optimum of 6.5 and pKa values of 4.60 and 8.65. Activity is inhibited by the tissue inhibitor of metalloproteinases-1 in a 1:1 stoichiometric interaction. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis in conjunction with N-terminal sequencing revealed that, as with all other matrix metalloproteinases similarly studied, promatrilysin activation was accompanied by the stepwise proteolytic removal of an M(r) 9000 propeptide from the N-terminus. The intermediates generated were dependent on the mode of activation used but, in all cases studied, activation terminated with an autocatalytic cleavage at E77-Y78 to yield the final M(r) 19,000 active matrilysin. From an analysis of the stability of the various intermediates, we propose that the sequence L13-K33 is particularly important in protecting the E77-Y78 site from autocatalytic cleavage, thereby maintaining the latency of the proenzyme.
Biochemistry 1992 Sep 15
PMID:Biochemical characterization of matrilysin. Activation conforms to the stepwise mechanisms proposed for other matrix metalloproteinases. 139 Jun 35

Extracts of human MCF 7 mammary carcinoma cells, the human lymphoblastoid cell lines AEH 1 and IM 9, T-cell derived CCRF cells, HL 60 myeloic leukaemia cells and murine myeloma cells SP 0 and NS I were analysed for immunoreactivity with polyclonal goat antibodies raised against homogeneous preparations of C-terminal fragments (32 kDa) of porcine uterine oestradiol receptor (ER). Whole cells and low speed cytosols were analysed for specific oestradiol-binding activity. ERs were enriched from cell extracts by either fractionated ethanol precipitation (0-25% (v/v) ethanol) and/or microscale-immunoaffinity chromatography. Immunoreactive proteins of identical molecular weight (approximately 65 kDa) were detected in all cell lines examined. Whole cell binding assays showed specific oestradiol-binding activity in MCF 7, IM 9 and CCRF cells. Borderline binding was found in HL 60 myeloid cells. No specific binding could be detected in AEH 1, NS I and SP 0 cells. Identical results were obtained using agar-electrophoresis after dextran-coated charcoal treatment. Immunoaffinity purified ERs from MCF 7, AEH 1 and HL 60 cells were subjected to limited proteolysis, where identical tryptic fragments were generated. In conclusion, we have confirmed by immunological methods that ERs are expressed in a variety of cell lines derived from the immune system and the haematopoietic system. The lack of specific hormone binding or very low-affinity hormone binding in some of the cells examined may be due to post-translational events or point mutations.
J Endocrinol 1992 Sep
PMID:Immunological detection of the oestradiol receptor protein in cell lines derived from the lymphatic system and the haematopoietic system: variability of specific hormone binding in vitro. 140 47

In 43 cases of various B-cell lineage tumors, precise gene structures of rearranged immunoglobulin heavy chain (IgH) were studied. By Southern-blot analysis of D upstream (5'D) gene of IgH, biallelic rearrangement structures, D-J or V-D-J, were determined and consequently maturational stage specific IgH rearrangement patterns were investigated. B-precursor ALL cases (especially stage IV of Nadler's criteria) have V-D-J rearranged IgH genes on both alleles. In contrast, most of the mature B-cell malignancies, excluding multiple myeloma, have IgH genotype of D-J/V-D-J. In addition, in case of D-J/V-D-J, the D gene used in D-J joining has been speculated by Southern-blot of D genes. So, these approaches for inquiring precise structures of rearranged IgH genes are supposed to provide new information of lymphocyte differentiation and leukemogenesis.
Leuk Res 1992 Sep
PMID:Maturational stage specific immunoglobulin heavy chain gene rearrangements, determined by D and D upstream region gene structures. 140 17

FtsA is an essential cell division protein in Escherichia coli. Its synthesis in low amounts makes the investigation of its functions difficult. Partially purified FtsA protein was obtained by solubilizing cellular inclusion bodies after overexpression of the ftsA gene for the purpose of raising monoclonal antibodies. Mice were immunized with this FtsA protein fraction and their spleen cells were fused to Sp2/0-AG14 mouse myeloma cells. Hybrid cells were screened and two clones were positively identified as FtsA monoclonal antibody producers by enzyme-linked immunosorbent assay and Western blotting. A quantitative assay using these monoclonal antibodies indicated that the average number of FtsA molecules per cell to be between 50 and 200. However, the concentration of FtsA protein normalized to total cell protein was constant over a wide range of growth rates. This finding is in agreement with the hypothesized role of FtsA protein as a stoichiometric component of the septum.
Mol Microbiol 1992 Sep
PMID:Quantitative determination of FtsA at different growth rates in Escherichia coli using monoclonal antibodies. 140 87

L factor, originally discovered in a subclone of mouse L cells, is a multicopy mammalian plasmid whose structure is related to that of polyoma. When a composite DNA consisting of L factor, pBR, bacterial neo, and an immunoglobulin (kappa) gene was introduced into mouse myeloma cells, the DNA was established as plasmids in the cells without rearrangement or integration into the chromosomes. The plasmid-bearing myeloma cells produced kappa mRNA and the gene product, kappa immunoglobulin, which were apparently derived from the gene located on plasmid L factor. These results suggest that L factor can be used as a plasmid expression vector for studies on gene expression and production of biologically active substances in mammalian cells.
Plasmid 1992 Sep
PMID:Production of an immunoglobulin gene product by the plasmid expression vector L factor in mouse myeloma cells. 140 75

Bone marrow fibrosis is known in myelomatosis and depends on the extent of plasma cell infiltration. The serum concentration of the aminoterminal propeptide of type III procollagen (PIIINP) has previously been reported to reflect fibrogenesis in the marrow in myelofibrosis. Here we followed 15 consecutive patients with newly diagnosed multiple myeloma with repeated PIIINP measurements during treatment with intermittent courses of melphalan and prednisolone. PIIINP was found to change with clinical behaviour of the disease, nonresponders and patients with recurrent disease having elevated values and the values in responders decreasing to the normal level or remaining there. Collagen fibres in plasma cell infiltrates of biopsies from bone marrow or skeletal tumours of these patients stained heavily with antibodies against PIIINP. Our results suggest that PIIINP works as a noninvasive indicator of bone marrow fibrogenesis. In multiple myeloma PIIINP is a sensitive, but not specific marker of disease course.
Br J Haematol 1992 Sep
PMID:Monitoring of multiple myeloma and bone marrow fibrosis with aminoterminal propeptide of type III collagen (PIIINP). 141

In 54 patients with multiple myeloma plasma cell infiltration was compared in bone marrow biopsies and aspirates. In 48% of cases plasma cell infiltration was comparable, in 48% infiltration in the aspirate was lower than in the biopsy. In only two cases more plasma cells were found in the aspirate. Eleven patients (20%) had less than 20% plasma cells in the aspirate and more than 50% in the biopsy. Underestimation of plasma cell load especially seems to occur in patients with a focal growth pattern of multiple myeloma or when strong fibrosis is present. 69% of patients with stage III, according to Durie & Salmon (1975), and 76% of patients with a high beta 2-microglobulin had more than 50% plasma cells in the biopsy, indicating that these parameters, which are based on tumour load, are influenced by other factors as well. The bone marrow biopsy is of superior value for direct estimation of the tumour load in multiple myeloma compared to bone marrow aspirates. A prospective study is needed to determine its prognostic significance.
Br J Haematol 1992 Sep
PMID:Comparison of plasma cell infiltration in bone marrow biopsies and aspirates in patients with multiple myeloma. 141 1


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