Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0019204 (hepatocellular carcinoma)
71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined the ability of NaCl (at 0.15 to 3 M) to release non-histone proteins from chromatin of cultured rat hepatoma cells. The percentage of the non-histones released increased with increasing NaCl concentrations up to 0.75 M; 1 and 3 M NaCl were not significantly more effective. A maximum of 50% of the non-histone protein was recovered free of DNA. The release of non-histones from sheared and unsheared chromatin was similar. The electrophoretic patterns of the non-histone proteins released by NaCl resembled that of the non-histones released by sodium dodecyl sulfate, which indicates that many of the detectable components were at least partially released by NaCl. Some non-histones (especially low molecular weight polypeptides) were fully released by NaCl and other proteins were relatively resistant to NaCl release. Higher recoveries of NaCl-dissociated non-histones were obtained with sucrose gradient centrifugation than with centrifugation in the absence of sucrose.
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PMID:Analysis of the effectiveness of sodium chloride in dissociating non-histone chromatin proteins of cultured hepatoma cells. 57 60

Buoyant-density centrifugation of unfixed chromatin has been performed in a newly devised medium containing 3-iodo-1,2-propanediol and metrizamide. Chromatins were obtained from isotopically labeled mouse hepatoma cells in suspension culture, either grown normally or density labeled in a medium containing bromodeoxyuridine, by mild digestion of isolated nuclei with micrococcal nuclease. When a mixture of normal and density labeled chromatin, marked with [14C]thymidine and [3H]bromodeoxyuridine, respectively, was centrifuged in the medium, chromatin peaks represented by labeled DNA were resolved to the extent expected from their separate banding profiles. Centrifugation of an equivalent chromatin mixture labeled with [14C] and [3H]lysine, respectively, also yielded resolution of chromatin peaks represented by labeled proteins. Only small amounts of labeled proteins were dissociated from chromatin in the gradient medium. Labeled proteins recovered from the gradient fractions were analyzed by electrophoresis on sodium dodecyl sulfate-polyacrylamide gels. The results suggested that most of the histones remained associated with the original stretches of DNA during the centrifual fractionation period. Essentially all of the dissociated proteins were found to be non-histone proteins.
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PMID:Fractionation of unfixed chromatin by buoyant-density centrifugation in gradients containing 3-iodo-1,2-propanediol and metrizamide. 64 Oct 28

Deoxyribonucleic acid polymerase-beta (EC 2.7.7.7) has been purified over 100 000-fold from a whole cell extract of guinea pig liver. The enzyme yields a single stainable band when subjected to non-denaturing polyacrylamide gel electrophoresis, and this band corresponds to the DNA polymerase activity when a sister gel is sliced and assayed. The final fraction has a specific activity of 21 000 units/mg; this value can be increased significantly by addition of various components, including glycols, polyamines or any of several protein factors which can be purified from the crude extract. The DNA polymerase-beta lacks detectable exonuclease or endonuclease activity, has an alkaline pH optimum and has a requirement for all four deoxyribonucleoside triphosphates, a divalent cation and a primer-template for maximal activity. While activated DNA is the preferred primer-template, the enzyme is capable of utilizing native and denatured DNA as well as several synthetic polynucleotides as primer-templates. The latter are especially effective when manganese is the divalent cation. Magnesium, at 10 mM, is the preferred divalent cation when activated DNA is used. Manganese, and to a lesser extent cobalt, can substitute for magnesium while zinc and calcium cannot. The beta-polymerase has a half-life of 10 min at 40 degrees C and this is increased in the presence of either DNA or NaCl. The enzyme is stimulated by glycols, polyamines and NaCal or KCl, and is inhibited by several known inhibitors of DNA polymerase activity including o-phenanthroline, heparin, organic solvents and sulfhydryl blocking agents. Guinea pig liver DNA polymerase-beta is remarkably similar to the rat Novikoff hepatoma beta-polymerase with respect to its isoelectric point of 8.4 and its molecular weight of 32 000 as determined by sucrose gradient centrifugation under high or low salt conditions or sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This similarity is further extended to the removal, at the final step in purification, of a protein capable of stimulating the homogeneous enzyme. Removal of this protein could explain the lower molecular weight of the guinea pig and other rodent-derived beta-polymerases, when compared to the beta-polymerases from other systems.
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PMID:Purification and properties of DNA polymerase-beta from guinea pig liver. 70 39

Protein 35/7.7 is an abundant cytosol protein of Morris hepatoma 3924A and Novikoff hepatoma which was not found in normal liver. Protein 35/7.7 was isolated from the cytosol of Novikoff hepatoma ascites cells by ammonium sulfate precipitation and DEAE-cellulose chromatography. It migrated as a single major spot on two-dimensional isoelectric focusing-SDS polyacrylamide gels. The N-terminal hexapeptide is Val-Asx-Pro-Thr-Val-Phe and its carboxyl-terminal amino acid is phenylalanine.
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PMID:Purification and partial characterization of protein 35/7.7 a cytosol protein that is abundant in rapidly growing hepatomas. 70 6

The nuclease activities of proteins, constituents of cytoplasmic ribosomes obtained from normal liver rats (Wistar) and C3HA mice as well as from hepatomas (both solid and ascites forms) transplanted into the above animals, were studied. RNA in membrane-bound ribosomes of normal rat liver incubated at 37 degrees C undergoes endogeneous hydrolysis resulting in formation, apart from acid-soluble products, of 6S, 8S and 11S fragments comprising 15 to 20% of the original amount of RNA. In contrast, in hepatoma membrane-bound ribosomes RNA treated likewisely remains intact. The proteins responsible for the RNase activity isolated from ribosomes were subsequently fractionated using ammonium sulfate and chromatography on DEAE-Sephadex columns and their properties were studied. The RNase activity completely disappeared from the membrane-bound ribosomes of Zajdela, 27 rat hepatomas and Guelstein hepatoma 22A, but not from the slow growing Guelstein hepatoma 48.
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PMID:[Nuclease activity of the cytoplasmic ribosomes of hepatocytes and several experimental hepatomas]. 71 53

A Glycoprotein, particularly high in tumors, has been extracted from Morris 5123C rat hepatomas and purified. The compound constitutes a major binding component for 67Ga in this hepatoma. It has a molecular weight of approximately 45,000. Its molecular weight was determined by sodium dodecyl sulfate:polyacrylamide gel electrophoresis and by Sephadex G-200 superfine gel filtration. The steps involved in its extraction and purification include ultrafiltration, gel filtration through Sephadex G-200 superfine, ion-exchange chromatography on diethylaminoethyl Sephadex A-50, and hydroxylapatite chromatography. The homogeneity of the compound was established by gel electrophoresis. The NH2-terminal residue, the percentage of nitrogen, the nonamino carbohydrate content, and the amino acid composition are reported.
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PMID:Isolation and partial characterization of a 67Ga-binding glycoprotein from Morris 5123C rat hepatoma. 71 29

The messenger activity for fructose 1,6-bisphosphate aldolase (EC4.1.2.13) (aldolase) A isozyme has been characterized in the polysome- or the messenger RNA-directed, protein-synthesizing system using the pH 5 fraction of rat liver or wheat germ extracts, respectively. The subunit of aldolase A synthesized in vitro was detected by immunoprecipitation with anti-aldolase A antibody raised in chickens followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The synthesis of the enzyme depended on the addition of polysomes or polyadenylate-containing RNA of rat ascites hepatoma AH 7974 cells which show a complete shift of aldolase isozyme to type A, whereas polysomes of adult rat liver were inactive. The messenger activity for aldolase A was present exclusively on free polysomes but absent on membrane-bound polysomes and in the soluble supernatant fraction of AH 7974 cells. The size of aldolase A messenger RNA determined by formamide-containing sucrose density gradient centrifugation was approximately 5.8 X 10(5) daltons corresponding to 1650 nucleotides. Taking into account the number of amino acid residues in the aldolase A subunit, approximately 400 nucleotides correspond to the noncoding region of aldolase A messenger RNA.
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PMID:Characterization of messenger RNA for fructose 1,6-bisphosphate aldolase A isozyme of rat ascites hepatoma AH 7974 cells. 76 Dec 23

We previously studied fibrinolysis and fibrinogenolysis by analyzing fragments of fibrin/fibrinogen degradation products (FDP) employing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. In this report, we characterized the fragments of FDP in four patients with disseminated intravascular coagulation (DIC), that were caused by various diseases. In the patients suffering from acute lymphoblastic leukemia (case 1) and acute suppurative cholangitis (case 3), DD and DY/X fragments resulting from fibrinolysis accounted for the most part of the FDP fragments. In case 3, D fragments resulting from fibrinogenolysis were also observed to much less extent. In a DIC associated with acute myeloblastic leukemia (case 2), both fibrinolysis and fibrinogenolysis were increased and resulted in high levels of D, Y and DY/X fragments, concomitant with moderate levels of DD and high molecular weight (HMW) fragments in the patient's sera. The increased fibrinogenolysis in this case was attributed to accelerated activation of plasmin. In a DIC patient of case 4, who underwent an operation due to hepatocellular carcinoma, marked increase in DY/X and HMW fragments and slight increase in DD fragment were observed on the day of operation. Hyperfibrinolysis documented in case 4 was explained by both increased production of thrombin and moderately accelerated activation of plasmin. Both qualitative and quantitative changes in the fragments of FDP during the courses of treatment in two cases of DIC were also noted. In summary, each underlying disease expresses characteristic pattern of FDP fragments in DIC.
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PMID:[Studies on the fragments of FDP in 4 patients with DIC]. 130 14

Plasma tissue-type plasminogen activator (t-PA) is cleared rapidly in vivo by the liver. Previous studies with the human hepatoma cell line HepG2 have identified a clearance system for t-PA modulated by plasminogen activator inhibitor type 1 (PAI-1). In the present study, a rat hepatoma cell line MH1C1 is shown to contain a PAI-1-independent t-PA clearance system. At 4 degrees C, binding of 125I-t-PA to MH1C1 cells was rapid, specific, and saturable. Scatchard analysis of the binding data yielded a mean estimate of 105,000 high affinity binding sites per cell (Kd = 4.1 nM). When the bound ligand was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the majority (about 90%) of the specific binding was in the form of uncomplexed 125I-t-PA. This is in contrast to HepG2 cells in which specific binding was mainly in the form of a sodium dodecyl sulfate-stable 125I-t-PA.PAI-1 complex. When availability of matrix-associated PAI-1 was blocked by preincubation with anti-PAI-1 antibody or removed by elastase treatment, specific 125I-t-PA binding to MH1C1 cells was unaffected, whereas most of the specific 125I-t-PA binding to HepG2 cells was abolished. Furthermore, when the active site of t-PA was inactivated with diisopropyl fluorophosphate, the diisopropyl fluorophosphate-t-PA specifically competed for binding of 125I-t-PA to MH1C1 cells, but failed to block specific 125I-t-PA binding to HepG2 cells. At 37 degrees C, PAI-1-independent t-PA binding to MH1C1 cells was followed by ligand uptake and degradation with kinetics similar to that seen in HepG2 cells. Chemical cross-linking of t-PA to MH1C1 cells revealed a specific t-PA binding protein with a molecular mass of about 500,000 daltons. Ligand-receptor complexes generated by chemical cross-linking were immunoprecipitable by anti-t-PA antibody but not by anti-PAI-1 antibody, further supporting the finding that binding of t-PA to MH1C1 cells is PAI-1-independent.
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PMID:Identification and partial characterization by chemical cross-linking of a binding protein for tissue-type plasminogen activator (t-PA) on rat hepatoma cells. A plasminogen activator inhibitor type 1-independent t-PA receptor. 132 1

Recombinant tissue factor pathway inhibitor (rTFPI) has been expressed in four mammalian expression systems using human SK hepatoma, mouse C127, baby hamster kidney (BHK), and Chinese hamster ovary (CHO) cells as hosts. On sodium dodecyl sulfate polyacrylamide gel electrophoresis, the immunoaffinity purified rTFPIs all show broad bands and the mean molecular weight of SK hepatoma and C127 rTFPIs (M(r) approximately 38,000) appear larger than those of BHK and CHO rTFPIs (M(r) approximately 35,000). All these proteins inhibit factor Xa and appear to bind factor Xa with 1:1 stoichiometry. The ability of these proteins to inhibit tissue factor-induced coagulation in plasma was examined using a prothrombin time assay. The relative activities of SK rTFPI:C127 rTFPI:BHK rTFPI:CHO rTFPI were found to be 28:15:2.1:1. By Western blot using specific antisera against the amino- and carboxy-termini of TFPI as probes, it is found that all the immunoaffinity purified rTFPIs possess approximately equal amounts of the amino terminus, but the C127 and BHK rTFPIs are deficient in carboxy terminus and the CHO rTFPI is essentially devoid of this region of the protein. Mono S chromatography allowed separation of the full-length and the truncated molecules with high and low anticoagulant activities, respectively. The above results suggest that proteolysis of the carboxy terminus of TFPI occurs to different extent when TFPI is expressed in different cells and that the carboxy terminal region of the TFPI molecule is important for the inhibition of tissue factor-induced coagulation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparison of recombinant tissue factor pathway inhibitors expressed in human SK hepatoma, mouse C127, baby hamster kidney, and Chinese hamster ovary cells. 132 78


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