Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cultured mouse myeloma cells were transfected with expression vectors encoding the aspartyl proteinase, human renin. The full construct, encoding the renin precursor prorenin, allows transfected cells to secrete the enzymically inactive pro-protein. Activity is detectable only following trypsin treatment which mimics the physiological activation step. Accordingly, it appears that myeloma cells do not contain detectable levels of an appropriate activating proteinase. However, when these cells are transfected with a construct from which the pro-peptide coding sequence has been deleted, they secrete an apparently fully active enzyme which is indistinguishable from mature renin. We conclude that expression of the pro-peptide is not necessary to allow correct folding of the molecule and its passage through the secretory pathway.
 ...
PMID:The pro-peptide is not necessary for active renin secretion from transfected mammalian cells. 267 96

Monoclonal antibody (Mab) 1.93B7 was obtained by fusion of spleen cells from a diabetic NOD mouse with P3X63Ag8.653 myeloma cells and screening for complement mediated lysis of rat insulinoma (RIN) cells. Immunofluorescence studies revealed that this Mab binds to RIN cells but not to the rat pituitary tumour line GH3. The binding of Mab 1.93B7 to RIN cells was abolished by trypsin but not by neuraminidase treatment of the cells, suggesting that the antigen recognized is a protein. Mab 1.93B7 bound to approximately 30% of mouse (BALB/c) and rat islet cells which had been subjected to trypsin digestion and incubated as a single cell suspension for 12h to allow reexpression of trypsin sensitive antigens. Since Mab 1.93B7 is potentially pathogenic, as suggested by its reactivity to primary islet cells and its complement fixing capacity, we injected it into BALB/c and NOD mice. Cytotoxic activity against RIN cells was detected in the serum of the animals injected with Mab 1.93B7, but the Mab did not exert a diabetogenic action and failed to reverse diabetes when administered at onset in NOD mice. No modification of the course of spleen cell mediated transfer of diabetes in NOD mice was observed when the Mab was administered from the time of spleen cell inoculation to the appearance of glycosuria. The implications of the lack of an effect in vivo of Mab 1.93B7 under the conditions employed are discussed.
 ...
PMID:A cytotoxic monoclonal islet cell surface antibody from the NOD mouse. 269 57

Expression of receptors for IgA (Fc alpha Rs) was investigated on a panel of 35 human B cell lines by labelling with human secretory IgA (0.5 mg/ml) and flow cytometry analysis after staining with fluoresceinated goat anti-human secretory component and/or anti-alpha chain F(ab')2 fragments. Receptors for IgA could be demonstrated on one out of nine Burkitt's lymphoma cell lines, three out of five myeloma cell lines and five out of 21 lymphoblastoid cell lines. The percentage of Fc alpha R-positive cells within the same B cell line varied upon repeated examination. Human dimeric IgA1 lambda myeloma protein revealed the same number of IgA receptor positive cells as did secretory IgA, whereas monomeric IgA did not bind to Fc alpha R. Detection of Fc alpha R was not inhibited when the tests were carried out in the presence of human dimeric IgG, IgM, asialo-orosomucoid, and secretory component but it was abrogated by pre-treatment of the cells with trypsin. The binding characteristics of Fc alpha Rs were studied on the myeloma cell line Esteve, using 125I-labelled human dimeric IgA and secretory IgA. The binding was dose-dependent with rapid kinetics and specific inhibition by unlabelled secretory IgA. Scatchard plot analysis resulted in an equilibrium constant K ranging from 3.2 to 4.7 x 10(6) M/l. No correlation was observed between Fc alpha R expression and differentiation stage, monoclonality, polyclonality of the cell lines, or Ig class produced by the B cells.
 ...
PMID:Spontaneous expression of a low affinity Fc receptor for IgA (Fc alpha R) on human B cell lines. 278 48

Mouse and rat myeloma cell lines showed little or no rosette formation with sheep erythrocytes (SRBC) coated with rabbit IgG (rabbit EA) but showed marked rosette formation after treatment with trypsin, pronase or neuraminidase. These cell lines showed no rosette formation with SRBC coated with mouse IgG (mouse EA): treatment with trypsin enabled the detection of rosettes among the mouse myeloma cell lines but not by the rat myeloma cells. The F(ab')2 fragment of the anti-Fc receptor II antibody blocked the formation of rosettes with rabbit EA by mouse myeloma cell lines after treatment with trypsin. Aggregated mouse IgG1 and IgG2b subclasses strongly inhibited the formation of rosettes with rabbit EA, whereas aggregated mouse IgG2a showed a marginal inhibitory effect. A large amount of mouse IgG2a, however, caused significant inhibition. Our results also revealed that aggregated mouse IgG could bind to the rat myeloma cell line. The Fc rosette forming abilities of the enzyme-treated mouse and rat myeloma cells became reduced after cultivation both in the presence and absence of FCS but not after cultivation in the presence of cycloheximide, suggesting that cell surface substances, which may be glycoprotein that incompletely mask Fc receptors, are produced by myeloma cells.
 ...
PMID:Studies on the Fc receptors and masking substances on mouse and rat myeloma cells. 297 95

A complete amino acid sequence has been determined for the UP1 single-stranded DNA binding protein from calf thymus that was first described by G. Herrick and B. M. Alberts [(1976) J. Biol. Chem. 251, 2124-2132]. Peptides required to establish the UP1 sequence were isolated by reversed-phase HPLC of digests produced by endoproteinase Lys-C, trypsin, chymotrypsin, Staphylococcus aureus V8 protease, and cyanogen bromide cleavage of UP1. The purified peptides were coupled to aminopolystyrene prior to solid-phase sequencing. UP1 contains 195 amino acids and has a molecular weight of 22,162. UP1 has a blocked NH2 terminus and contains a single NG,NG-dimethylarginine residue near its COOH terminus. Gas-phase sequencing of tryptic peptides derived from an analogous protein from mouse myeloma cells [Planck, S. R. & Wilson, S. H. (1980) J. Biol. Chem. 255, 11547-11556] revealed that this mouse helix-destabilizing protein shares a high degree of sequence homology with UP1. Of the 59 amino acids in the mouse protein that have so far been found to be homologous with UP1, 48 correspond exactly to sequences found in UP1. Most of the 11 differences that have been found between the sequences of these two proteins are conservative in nature, involving primarily the interchange of chemically similar amino acids. One 9-residue mouse sequence that is not obviously homologous to UP1 may be a result of the larger size of the mouse myeloma protein as compared to UP1. Since none of the UP1 or mouse myeloma helix-destabilizing protein sequence appears to be homologous to that of any previously sequenced protein, we presume that these two proteins represent a distinct class of single-stranded nucleic acid binding proteins that probably play a role in metabolism of single-stranded RNA or DNA in vivo.
 ...
PMID:Amino acid sequence of the UP1 calf thymus helix-destabilizing protein and its homology to an analogous protein from mouse myeloma. 299 41

A murine monoclonal antibody, 1C5, was produced by fusion of spleen cells obtained from mice immunized with CAC-1, a human cell line of adenocarcinoma derived from uterine cervix, and NS/1 myeloma cells. 1C5 can be used for the staining of routine formalin-fixed and paraffin-embedded tissue sections. 1C5-defined antigen was found to have a molecular weight of 26,000. The 1C5-defined antigen was resistant to neuraminidase and trypsin treatment, but sensitive to periodate treatment, indicating that an epitope of the 1C5-defined antigen is a carbohydrate moiety. Immunohistochemical study using immunoperoxidase staining demonstrated that 1C5 reacted with 87% of adenocarcinomas of the uterine cervix, 39% of endometrial carcinomas of the uterus, 100% of ovarian mucinous cystadenocarcinomas, 43% of ovarian serous cystadenocarcinomas, 45% of adenocarcinomas of the colon, and 40% of gastric adenocarcinomas, thus showing the broad reactivity to adenocarcinoma cells of various origins. However, 1C5 did not show any reactivity to ectocervix epithelium, cervical intraepithelial neoplasia, or squamous cell carcinoma of the uterine cervix. In addition, adenocarcinoma of the uterine cervix exhibited strong cytoplasmic reactivity with 1C5, whereas endometrial carcinoma of the uterus showed the luminal reactivity. 1C5 also reacts with 95% ethanol-fixed malignant cells in cervical smears.
 ...
PMID:New monoclonal antibody, 1C5, reactive with human cervical adenocarcinoma of the uterus, with immunodiagnostic potential. 305 7

The Kva IgG2(k) myeloma protein showed a complete resistance to papain in the presence of cysteine at neutral pH, and a higher resistance to trypsin and alpha-chymotrypsin digestion than other IgG2 proteins. On the other hand, the Kva molecule was cleaved by pepsin at low pH to give the expected F(ab')2 fragment. When the cleavage conditions were altered, it was possible to obtain Fab, Fc, and Fc' fragments from this molecule as well. The Fab/c fragment and FacbFc' complex were also obtained, which have not previously been reported from human IgG2 molecules. Incubation at elevated temperatures (45-50 degrees C) and/or lower pH resulted mainly in enzymatic attack on the C terminal side of the hinge. It was necessary to destroy the hinge by reduction or to expose the Kva molecule at 70 degrees C or at lower pH (2.5) prior to digestion to facilitate enzyme digestion on the NH2 terminal side of the hinge. These results indicate that the hinge region of the Kva molecule has an unusually compact structure, which makes it extremely resistant to proteolysis.
 ...
PMID:Enzymatic fragmentation of an unusual human IgG2 (Kva) myeloma protein. 311 30

Interaction of DNA with eukaryotic cells under conditions similar to those providing DNA adsorption onto liposomes was studied. It was revealed that mouse fibroblasts (line A9) and myeloma cells bind phage and plasmid DNA in 0.3 M sucrose solution containing Mg2+-ions. Additional pretreatment of the cells by trypsin did not affect DNA adsorption efficiency. The major part of the adsorbed DNA recovered by salt treatment of the cells, but 10-15% of DNA was found to be irreversible. Up to 50% of the irreversibly bound DNA molecules retain their linear size after treatment of cells with DNAse I. Efficiencies of DNA adsorption and irreversibly binding depend on the concentration of Mg2+ in the medium. The process of DNA irreversible binding is not inhibited by drugs affecting cell metabolism. It is assumed that DNA adsorbs onto the phospholipid domains of the cell membrane, and part of the adsorbed DNA is taken up into the interior of the cells.
 ...
PMID:[Mg2+-dependent interaction of DNA with eukaryotic cells]. 325 55

A cell type-specific monoclonal antibody (Mab) against a cell surface antigen of rat anterior pituitary somatotrophs has been generated by fusion of a nonsecreting mouse myeloma line with spleen cells from a mouse immunized with enzymatically dispersed anterior pituitary cells of adult random cycling female rats. Hybridomas were initially screened for antibodies to cell surface antigens by an enzyme-linked immunosorbant assay using rat anterior pituitary cells and smooth muscle cells of aorta as positive and negative controls, respectively. Positive clones were further checked for cell type specificity by immunofluorescence. Mab WHC-1 is an immunoglobulin M (IgM) with kappa-light chains and is cytotoxic in the presence of complement. Based on double immunofluorescence, this Mab reacted with 22.5 +/- 2.0% (+/- SEM) of the anterior pituitary cells of adult random cycling female rats. Among them, about 93.5 +/- 1.4% were somatotrophs, and only 4.1 +/- 1.2% were mammotrophs. Approximately two thirds of the somatotrophs were Mab WHC-1-positive. The reaction of this Mab with gonadotrophs, thyrotrophs, or corticotrophs were negligible. The percentage of Mab WHC-1-positive cells derived from immunoperoxidase staining was significantly greater than that from immunofluorescence. The cell surface antigen defined by Mab WHC-1 is expressed heavily on GH3 cells, but not on smooth muscle cells. It is resistant to trypsin digestion, but sensitive to ethanol treatment, and exhibits the solubility property of a glycolipid. Mab WHC-1 cross-reacts with the anterior pituitary cell of rabbits, but not mice. These results provide the immunological evidence for heterogeneity among somatotrophs and demonstrate the feasibility of making pituitary cell type-specific Mabs.
 ...
PMID:Production and partial characterization of a monoclonal antibody to rat anterior pituitary somatotrophs. 327 36

The murine BALB/c myeloma LPC-1 demonstrates a periodic resistance to lysis by immune mechanisms; this correlates with the production and accumulation of a trypsin-sensitive, single chain glycoprotein of 160 kilodaltons gp160 on the tumor cell surface. Tumor cells obtained 4 days after transplantation are lysed by cytotoxic T lymphocytes whereas ten-day cells are resistant to lysis. The progressive resistance to lysis was correlated with an increasing amount of gp160 on the surface of LPC-1 cells. Cell surface morphology, as determined by scanning electron microscopy, showed that early cells consisted of equal proportions of cells having microvilli or ruffles. The late cell population consisted mainly of cells with microvilli. These microvilli were twice as abundant on late LPC-1 cells as on early cells. Transmission electron microscopy images of late LPC-1 cells suggested an active protein synthesis which correlated with a more intense deposition of ruthenium red and an increasing amount of gp160 on the cell surface.
 ...
PMID:Morphology surface of a mouse plasmacytoma (LPC-1) showing cyclic resistance to immune lysis. 348 27


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>