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)

Intracisternal A particles from the FLOPC-1 line of BALB/c myeloma have been shown to contain high-molecular-weight RNA (60 to 70S) that is sensitive to RNase, alkali degradation, and heat but resistant to Pronase treatment. The intracisternal A-particle RNA contains tract of poly (A) approximately 180 nucleotides long. As shown in a reconstitution experiment, by antigenic analysis of A-particle preparation and the SC cytopathogenicity assay, the 70S RNA was not due to contamination by type C virus particles. The FLOPC-1 intracisternal A particles also possess an endogenous RNA-dependent DNA polymerase. The enzyme required Mn2+ or Mg2+, dithiothreitol, detergent, and four deoxyribonucleoside triphosphates for maximum activity. Enzymatic activity was maximally stimuated by poly (rC)-oligo (dG)12-18 and less with poly (rG)-oligo (dC)10 or poly (rA)-oligo (dT)12-18 as compare with synthetic DNA/DNA duplex templates such as poly (dA)-oligo (dT)12-18. The enzyme can utilize the A-particle endogenous RNA as template as shown by analysis of the early and late DNA products of the endogenous reaction by CsSO4 isopycnic gradient centrifuation and hybridization of purified 70S or 35S A-particle RNA with the purified complementary DNA product. Approximately 50% of the A-particle complementary DNA also hybridized with oncornavirus RNA.
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PMID:Intracisternal A particles from FLOPC-1 BALB/c myeloma: presence of high-molecular-weight RNA and RNA-dependent DNA polymerase. 5 76

An ATPase was purified from mouse myeloma MOPC 70E the activity of which depends on the presence of single-stranded DNA and divalent cations such as Mg2+, Mn2+, Ca2+, Ni2+ or Fe2+. The enzyme splits both ribonucleoside and deoxyribonucleoside triphosphates but preferentially ATP and dATP yielding nucleoside diphosphates and inorganic phosphate. The enzyme has an absolute requirement for single-stranded DNA. Alternating double-stranded polydeoxynucleotides are only slight effective, and native double-stranded DNA, single-stranded and double-stranded RNAs as well as DNA - RNA hybrids are ineffective in stimulating the ATPase. The enzyme has further characterized by sedimentation in a sucrose density gradient (s20, w = 5.5 S) and by isoelectric focussing in an ampholine pH gradient (pI = 6.5).
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PMID:An ATPase depending on the presence of single-stranded DNA from mouse myeloma. 12 26

Differential effects of Mg2+, spermidine, and reticulocyte ribosomal wash factors on the translation of endogenous, myeloma, and globin mRNA's have been observed in studies with the wheat germ cell-free protein synthesizing system. Spermidine stimulated globin mRNA translation but not the translation of endogenous wheat germ messages, and the polyamine actually inhibited the translation of myeloma mRNA. Ribosomal wash factors, on the other hand, stimulated endogenous and myeloma mRNA dependent protein synthesis in an Mg2+-dependent fashion but inhibited globin mRNA translation. The combination of ribosomal wash factors and spermidine was either stimulatory or inhibitory depending on the Mg2+ concentration and the message. It was further observed that translation of exogenous myeloma mRNA proceeded for only 60 min at 25 degrees C under all conditions tested in this study, while translation of endogenous wheat germ messages continued for longer periods of time. No differential effects of spermidine on the synthesis of high molecular weight myeloma proteins were observed.
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PMID:Effects of ribosomal wash factors and spermidine on endogenous and exogenous mRNA stimulated protein synthesis in the wheat germ cell-free system. 45 21

Initial results of an approach to the isolation of functionally active chromatin are described. Slight digestion of mouse myeloma nuclei at 0 degrees C with micrococcal nuclease, followed by dialysis against near-physiological saline solution containing 1 mM Mg2+, caused release of up to 17% of the nuclear DNA as soluble nucleoproteins. This soluble (S) fraction was relatively depleted in H1 histones and methylated DNA (5-methylcytosine) but highly enriched in RNA, single-stranded DNA, and nonhistone chromosomal proteins, particularly two species of the high mobility group identified as HMG 1 and HMG 2. The S fraction released most rapidly (6--8% of the total DNA) consisted mainly of mono- and small oligonucleosomes. The mononucleosomes appeared normal in terms of sedimentation behavior, DNA length, and content of histones H2A, H2B, H3, and H4, but lacked H1, and instead were associated with approximately stoichiometric amounts of HMG 1 and HMG 2. Studies using isolated, fluorescence-labeled, total mouse HMG proteins indicated that added HMG 1 and HMG 2 do not bind strongly to S-fraction nucleoproteins but that two smaller HMG species (probably HMG 14 and HMG 17) do bind preferentially to S-fraction mono- and dinucleosomes. These results argue against artifactual redistribution of HMG 1 and HMG 2 during this fractionation but suggest caution in interpreting the distribution of smaller HMG proteins after digestion of chromatin. The potential relationship of this soluble fraction to transcriptionally active chromatin is discussed.
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PMID:Chromatin fractionation procedure that yields nucleosomes containing near-stoichiometric amounts of high mobility group nonhistone chromosomal proteins. 47 83

Cytoplasmic (high-molecular-weight) DNA polymerase was partially purified from mouse myeloma. Upon chromatography on DEAE-Sephadex, following fractionation on phosphocellulose, the enzyme was resolved into three species named CI, CII, and CIII. The species CI and CII have equal sedimentation coefficients (10.5 S) in sucrose gradients without salt. In the presence of 125 mM ammonium sulfate the sedimentation coefficients are reduced to 8.6 S. The species CIII shows sedimentation coefficients of 5.7 S and 5.2 S without salt and in the presence of 125 mM ammonium sulfate, respectively. This species is assumed to be an artifact arising from either CI or to a minor extent from CII. The optima for pH, KCl and Mg2+ concentration, and the extent of inhibition by N-ethylmaleimide are the same. However, the enzymes differ in their responses to Mn2+ (substituting for Mg-2+), and to addition of ethanol, dimethylsulfoxide, and various phospholipids in the assay mixture. The enzymes prefer poly[d(A-T - d(A-T)] or partially degraded (activated) DNA as template rather than double-stranded or single-stranded DNA. The activity on activated DNA relative to that on poly[d(A-T) - D(A-T)] was found to be 93, 66, and 29% for DNA polymerases CI, CII, and CIII, respectively.
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PMID:High-molecular-weight DNA polymerases from mouse myeloma. Purification and properties of three enzymes. 116 71

The radiosensitivity of mouse myeloma and E. coli cells in the presence of Mg2+ and UO2(2+) ions has been investigated. It has been shown that Mg2+ ions (10(-4) M) do not influence the viability of E. coli and mouse myeloma cells. The presence of Mg2+ ions during irradiation reduces the survival rate of E. coli cells, but the addition of Mg2+ ions after irradiation does not influence the radiosensitivity of E. coli cells. Comparison of the results on the influence of Mg2+ ions upon cells and bilayer lipid membranes (BLM) permits us to suppose that Mg2+ ions increase the positive charge of the membranes thus promoting the increase in the number of short-lived radiolysis products which impair membranes and increase cell radiosensitivity. UO2(2+) ions (10(-4) M) increase the radioresistance of E. coli cells which can be associated with the increase in the lateral membrane viscosity, as it was shown in the studies on BLM.
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PMID:[Changes in cellular radiosensitivity by modifying the cytoplasmic membranes]. 141 Feb 94

Membrane currents through the Ca2+ channel were studied in a hybridoma cell line (MAb-7B) constructed by fusion of S194 myeloma cells and splenic B lymphocytes from the mouse. The whole-cell variation of the patch-electrode voltage-clamp technique was used. When [Ca2+]o = 2.5 mM, [Na+]o = 150 mM and [Na+]i = 155 mM, the current reversed from inward to outward at 20.9 +/- 2.4 mV (mean +/- S.D., n = 62). Both inward and outward currents showed voltage-dependent inactivation with the same membrane potential dependence of steady-state inactivation. The decay time constant of the current decreased from about 27 ms at -44 mV to a saturation value of 16 ms at about -20 mV, and remained at this value even when the current became outward. From the above results both the inward and outward currents were considered to flow through Ca2+ channels. The inward current showed no change when the external Na+ was replaced with Cs+ or tetraethylammonium and increased when [Ca2+]o was increased. Also, the reversal potential became more positive with increasing [Ca2+]o with a slope of 29 mV/decade change of [Ca2+]o. Effects of different divalent cations examined at 10 mM concentration showed the reversal potential to become more positive in the order of Mn2+, Sr2+ approximately equal to Ba2+ and Ca2+ whereas the relative maximum amplitudes of peak inward current were 1.0 for Ca2+, 1.24 for Sr2+, 0.99 for Ba2+ and 0.07 for Mn2+. When [Ca2+]o or [Mg2+]o was reduced by chelators, monovalent cations became capable of carrying inward current through the Ca2+ channel. These monovalent currents share common kinetic properties with the Ca2+ current, as judged from the steady-state inactivation and the decay time constant of the current. The monovalent cation current was blocked by divalent cations in a voltage-dependent manner. The half-blocking concentrations of Ca2+ and Mg2+ at -45 mV were 2.0 X 10(-6) M and 3.0 X 10(-5) M respectively. The same voltage-dependent binding mechanism can explain the outward current carried by monovalent cations at large positive potentials at normal Ca2+ concentrations. The suppression of the monovalent currents by Ca2+ and Mg2+ showed different voltage dependences. The suppression by Ca2+ increased and then decreased as the membrane potential was made negative, whereas the suppression by Mg2+ increased monotonically. This difference can be explained by considering the fact the Ca2+ is permeant and Mg2+ is impermeant through the Ca2+ channel.
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PMID:Currents carried by monovalent cations through calcium channels in mouse neoplastic B lymphocytes. 258 82

An SP6/mouse insulin RNA precursor containing two exons and one intron can be spliced in a partially purified nuclear extract isolated from MOPC-315 mouse myeloma cells. We have detected the putative RNA splicing intermediate (intron-3'exon) in a lariat form, the excised intron in a lariat form, and the mRNA spliced product. The in vitro splicing reaction of gel-purified RNA precursors requires ATP and Mg2+ and was accompanied by the formation of a 60-40S ribonucleoprotein complex. The formation of the 60S complex requires ATP. At least two Sm snRNPs containing U1 and U2 RNAs are components of the 60-40S complex. The assemble of those snRNPs occurs early during the splicing reaction and it requires ATP and intron containing pre-mRNAs.
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PMID:Assembly in an in vitro splicing reaction of a mouse insulin messenger RNA precursor into a 60-40S ribonucleoprotein complex. 294 May 12

In order to define the optimum conditions of electrofusion technique for the generation of antibody-producing hybridomas, mouse spleen cells or EBV-transformed human B cells were fused with mouse myeloma cells (SP2/0) or human fusion partner cells (KR-4 or KR-12), respectively, by electric field pulse under various conditions. The results confirm reports that the presence of both Ca2+ and Mg2+ in fusion medium and pretreatment of mixed cells with proteases improve hybridoma yield. Moreover, the presence of liposome or hydrophobic protein in the fusion medium greatly enhanced the yield. Under optimum conditions, hybridoma yields of mouse cells and human cells were 2.5 X 10(-4) and 1 X 10(-4), respectively. These efficiencies were about ten times higher than those obtained by the conventional polyethylene glycol technique. Microscopic observation of the fusion-process revealed that in a human cell system 20%-50% of the cells were physically fused, although only one in 5000 physically fused human cells grew as a hybridoma after hypoxanthine-aminopterin-thymidine selection.
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PMID:Improvement in the basic technology of electrofusion for generation of antibody-producing hybridomas. 311 Feb 94

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.
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PMID:[Mg2+-dependent interaction of DNA with eukaryotic cells]. 325 55


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