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)

Purification of alpha-fetoprotein from mouse hepatoma BW7756 extracts was performed using ammonium sulfate precipitations, gel filtration, ion-exchange chromatography and isoelectric focusing. These procedures produced a 5.6% yield of alpha-fetoprotein with 96% purity. Polyacrylamide slab gel electrophoresis, extended agarose electrophoresis and immunoelectrophoresis demonstrated that mouse hepatoma alpha-fetoprotein migrated at pH 8.6 as a rapid alpha1, or postalbumin globulin. Crossed antibody electrophoresis of the agarose zone containing alpha-fetoprotein failed to demonstrate microheterogeneity. Molecular weight analysis of the mouse hepatoma alpha-fetoprotein on a calibrated Sephadex G-200 column yielded a value of 72 000-73 000 for the native protein. Sodium dodecyl sulfate gel electrophoresis subsequently demonstrated a single polypeptide chain with a molecular weight of 72 000. Amino acid analysis showed the alpha-fetoprotein to be an acidic protein dominated by hydrophobic residues. The total carbohydrate content was 5.5%, and 3 mol of sialic acid were detected per mol of alpha-fetoprotein. Although neutral sugars were the principal class present, galactosamine was the most abundant single sugar detected.
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PMID:Isolation and characterization of alpha-fetoprotein from the mouse hepatoma BW7756. 6 68

Enzyme deviations in injured livers were studied by analyzing isozyme patterns of phosphorylase using a newly developed electrophoretic method, which separates six molecular species of this enzyme, i.e. M,FM,F,L,L', and FL'. In hepatic injuries caused by CCl4 and galactosamine intoxications of rats, F appeared in early stages and L' (and FL') in later stages of the injuries with a concurrent decrease or loss of L, which is a sole isozyme component of adult liver. In injured livers of patients with hepatitis and cirrhosis of the liver, increases in FL' activity were also found. Appearance of F was found only in hepatocellular carcinoma. The results obtained with phosphorylase isozyme analysis support the idea that an undifferentiated gene expression takes place in the injured livers of non-malignant hepatic disorders.
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PMID:Studies of liver phosphorylase in hepatic injuries II. Alteration in isozyme pattern. 15 93

High levels of a novel vitamin B12-binding protein (hepatoma B12 BP) have been observed recently in plasma obtained from three adolescent patients with hepatocellular carcinoma. This protein has now been isolated in homogeneous form from the plasma and pleural fluid of two of these patients by the use of affinity chromatography with vitamin B12-Sepharose. The hepatoma B12 BP belongs to the R-type group of B12-binding proteins and is essentially indistinguishable from the recently isolated human milk and saliva R-type proteins in terms of: (a) immunologic properties based on immunodiffusion and immunoprecipitation assays; (b) amino acid composition; (c) molecular weight based on amino acid and carbohydrate content; and (d) absorption spectra. Both hepatoma B12 BPs contain more sialic acid and less fucose than the milk and saliva B12 BPs. All four proteins contain similar amounts of galactose, mannose, galactosamine, and glucosamine. Differences in sialic acid content appear to account for the differences in electrophoretic mobility that were observed among the four proteins. Differences in total carbohydrate content appear to account for the differences in apparent molecular weight that were observed with both gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Tumor tissue from one of the patients contained 10 times as much R-type protein as did normal liver tissue from the same patient. This suggests, although it does not prove, that synthesis by the tumor is the cause of the high levels of R-type protein found in the plasma of certain patients with hepatocellular carcinoma. Plasma survival studies performed with rabbits indicate that the hepatoma B12 BP has a prolonged plasma survival and suggests that his parameter is also of importance.
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PMID:Isolation and characterization of a novel vitamin B12-binding protein associated with hepatocellular carcinoma. 17 Dec 83

Plasma membranes were isolated from an ascites hepatoma, AH 130, by the fluorescein mercuric acetate (FMA) method. Glycopeptides and mucopolysaccharides were prepared by digesting the membranes with pronase, then by fractionating the digest chromatographically and electrophoretically. Isolated fractions were analyzed for their amino acid and carbohydrate compositions. Results were compared with those for corresponding fractions from AH 66 (J. Biochem. 76, 319-333 (1974)). Mucopolysaccharides and a series of glycopeptides were isolated from the fraction excluded from Sephadex G-50. The mucopolysaccharides were identified as a family of heparan sulfates with different electrophoretic mobilities. The glycopeptides contained serine, threonine, galactose, galactosamine, glucosamine, and sialic acid as the major constituents as aspartic acid and mannose as minor ones. This suggests that most of the carbohydrate moieties are linked to serine or threonine (O-glycosidic), and that some are linked to asparagine (N-glycosidic). No nearly purely O-glycosidic glycopeptides were found in this fraction from AH 130, through they were the major glycopeptides from the AH 66 plasma membranes. In the fraction included in the gel, glycopeptides containing fucose, galactose, mannose, glucosamine, glaactosamine, and sialic acid were found. The presence of galactosamine suggests that some of the glycopeptides are O-glycosidic though most are N-glycosidic. In the corresponding fraction from AH 66, nearly purely N-glycosidic glycopeptides were found.
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PMID:The isolation and characterization of glycopeptides and mucopolysaccharides from plasma membranes of an ascites hepatoma, AH 130. 17 52

Antibodies to chromatin proteins of Novikoff hepatoma cells formed precipitin bands in the double-diffusion immunoprecipitation assay with chromatin proteins of Novikoff hepatoma, Walker 256 carcinosarcoma, and 18-day fetal rat liver. The antigen used for preparation of antiserum was the chromatin proteins initially extracted with 3 M NaCl-7 M urea and soluble after dialysis to 0.14 M NaCl-0.35 M urea. The chromatin proteins used for analytical studies were extracted with 0.6 M NaCl containing 0.01 M Tris-HCl (pH 8) and 100 muM phenylmethylsulfonyl fluoride. Corresponding chromatin proteins of normal and 18-hr regenerating rat liver, heart, and kidney did not form precipitin bands. The antigen was purified from the chrmatin of Novikoff hepatoma cells by exclusion chromatography on Sephadex G-150 and preparative nondenaturing polyacrylamide gel electrophoresis. Its migration on denaturing sodium dodecyl sulfate-polyacrylamide gels corresponded to a molecular weight of 26,000. Amino acid analysis showed that the ratio of acidic to basic amino acids was 1.4 to 1.0. Evidence for its homogeneity included its migration as a single protein spot on two-dimensional polyacrylamide gel electrophoresis and its single lysine amino-terminal amino acid. This protein is a glycoprotein, as shown by the presence of 15 moles of galactosamine per mole of antigen. These studies demonstrate the presence of a fetal glycoprotein in the chromatin of two tumors that may have an important role in determining their gene products.
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PMID:A fetal protein in chromatin of Novikoff hepatoma and Walker 256 carcinosarcoma tumors that is absent from normal and regenerating rat liver. 18 70

Plasma membranes were isolated from an ascites hepatoma, AH 130 FN, a free-cell type subline of AH 130, by the fluorescein mercuric acetate (FMA) method. Glycopeptides and mucopolysaccharides were prepared from the membranes by pronase digestion then fractionated chromatographically and electrophoretically. Isolated fractions were analyzed for amino acid and carbohydrate compositions. The results were compared with those for corresponding fractions from AH 66 and AH 130 ((1974) J. Biochem. 76, 319-333; (1975) ibid., 78, 863-872). The fraction excluded from Sephadex G-50 contained mucopolysaccharides and a series of glycopeptides. The mucopolysaccharides were identified as chondroitin sulfate A on the basis of their chemical composition, electrophoretic behavior on cellulose acetate and digestibility with chondroitinase AC [EC 4.2.2.5]. This contrasts with previous findings that mucopolysaccharides from the corresponding fractions from AH 130 and AH 66 were heparan sulfate. The chemical composition of the glycopeptides, which showed high contents of threonine, serine, galactose, galactosamine, glucosamine, and sialic acid, indicated the presence of glycopeptides with O-glycosidic linkages. The glycopeptides also contained a small but significant amount of aspartic acid, suggesting that N-glycosidic glycopeptides were also contained in this fraction. The fraction included in Sepnadex G-50 contaoned N-glycosidic glycopeptides as major components, since the carbohydrate moieties were composed of fucose, galactose, mannose, glucosamine, sialic acid, and a smaller amount of galactosamine. The presence of galactosamine suggested that O-glycosidic glycopeptides were present as minor components. Glycopeptides with both O- and N-glycosidic linkages were isolated from AH 130, but not from AH 66.
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PMID:The isolation and characterization of glycopeptides and mucopolysaccharides from plasma membranes of an ascites hepatoma, AH 130 FN. 18 82

We tested an experimental approach in which the specialized enzymatic pattern characteristic of the tissue of origin of a tumor might be exploited to target and enhance drug selectivity. In the present work, the D-galactosamine-induced depletion of uridine 5'-triphosphate (primarily a hepatic event) was employed to enhance the growth inhibition caused by 3-deazauridine. As predicted, the drug effect was most pronounced in the slower growing, well differentiated hepatoma lines where the activities of certain hepatic metabolic pathways and enzymes, though decreased, were still operative. The interactions of D-galactosamine and cytosine arabinoside with 3-deazauridine were examined in vitro in four liver tumor cell lines and two nonhepatic lines. The effects of D-galactosamine and 3-deazauridine on the growth of the Morris hepatoma cell lines 3924A, 8999S,AND 8999R were strongly synergistic; on the Novikoff hepatoma and the nonhepatic cell lines they were only additive. The combination of 3-deazauridine with cytosine arabinoside gave approximately additive growth inhibition with all cell types, without selective toxicity towards the hepatocellular lines. Results of growth-inhibition studies with the combination of D-galactosamine and cytosine arabinoside and with combinations of all three agents are also presented. These results are analyzed in the context of the regulation of hepatic pyrimidine nucleotide metabolism and our design of enzyme pattern directed drug selectivity.
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PMID:Enzyme pattern-directed chemotherapy: synergistic interaction of 3-deazauridine with D-galactosamine. 18 52

A selective deficiency of uridine triphosphate (UTP) was induced in AS-30D rat ascites hepatoma cells by the synergistic action of D-galactosamine and 6-azauridine. The resistance of these hepatoma cells to low concentrations of D-galactosamine (less than 2 mM) was due to their active de novo pyrimidine synthesis which compensated the trapping of uridylate in the form of uridine diphosphate-amino sugars derived from D-galactosamine. The additional blockage of de novo pyrimidine synthesis led to noncompensated uridylate trapping with a UTP content of less than 0.05 mmole/kg of cell wet weight as compared to the control level of 0.66 mmole/kg. The induction of UTP deficiency by incubating the cells with low concentrations of D-galactosamine and 6-azauridine (0.5 mM each) was not accompanied by significant changes in the content of adenine and guanine nucleotides, uridine diphosphate glucose, and uridine diphosphate galactose. The depletion of UTP pools could be reversed within 10 min by the addition of uridine; orotate or uracil were completely ineffective in these hepatoma cells. A UTP content in the range of 0.1 to 0.4 mmole/kg, induced by either 6-azauridine or D-galactosamine, was associated with a reversible depression of cell growth in suspension culture. A UTP content below 0.05 mmole/kg led to irreversible growth inhibition and to necrocytosis in culture, as well as to a loss of transplantability in vivo. Uridine reversal studies indicated that the percentage of cells able to resume growth in culture decreased with an increasing time period of UTP deficiency. The deficiency period required for irreparable or lethal damage in these hepatoma cells ranged from 3 to 20 hr. The principle of noncompensated uridylate trapping can be extended to other inhibitors of nucleotide synthesis combined with various nucleotide-trapping sugar analogs. Noncompensated nucleotide trapping may be useful for an induction of selective nucleotide deficiencies in tumor cells.
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PMID:Uridine triphosphate deficiency, growth inhibition, and death in ascites hepatoma cells induced by a combination of pyrimidine biosynthesis inhibition with uridylate trapping. 18 18

In order to evaluate the role of hexosamine metabolism in tumor tissue, we studied the biodistribution of N-(F-18)-fluoroacetyl-D-glucosamine (FAGlu) in male Donryu rats bearing poorly differentiated hepatomas (AH109A and AH272). Compare with the former result of the high tumor uptake of FAGlu in C3H/He mice bearing well differentiated spontaneous hepatoma, the tumor uptakes of FAGlu in these tumors showed the lower values. This suggested that spontaneous hepatoma maintained a high activity of glucosamine metabolism, while poorly differentiated hepatoma had little activity. Metabolism of glucosamine in tumor tissue may be another marker for characterizing tumors. We also discuss the tissue distribution of new F-18 labeled hexosamines, N-(F-18)-fluoroacetyl-D-mannosamine and N-(F-18)-fluoroacetyl-D-galactosamine in tumor bearing rats.
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PMID:N-(F-18)-fluoroacetyl-D-glucosamine: a new positron labeled pharmaceutical for cancer study. 130 16

The identification of free glycoinositol phospholipids (GPIs) following biosynthetic labeling with [3H]glucosamine in cultured cells has been reported by several laboratories. We applied this procedure to two of the cell types used in these studies, H4IIE hepatoma cells and isolated hepatocytes, but were unable to detect a [3H]glucosamine-containing lipid that met any of the criteria for GPIs, including sensitivity to phosphatidylinositol-specific phospholipase C (PIPLC) or GPI-specific phospholipase D. Part of the difficulty in radiolabeling a GPI by this procedure was the rapid metabolic conversion of [3H]glucosamine to galactosamine and neutral or anionic derivatives. A PIPLC-sensitive radiolabeled lipid was detected only after 16 h of labeling. The water-soluble fragments released from this lipid by PIPLC corresponded largely to myo-inositol 1,2-cyclic phosphate and myo-inositol 1-phosphate, products expected from PIPLC cleavage of phosphatidylinositol or lyso-phosphatidylinositol. In an alternative approach that we introduce here, free GPIs in lipid extracts from rat liver plasma membranes were labeled by reductive radiomethylation. This procedure, which radiomethylates primary and secondary amines, has been shown to label a glucosamine residue adjacent to inositol in all GPIs characterized to date. The labeled extracts were fractionated by two-dimensional thin-layer chromatography, and a cluster of polar labeled lipids were assigned as GPIs based upon the following observations. 1) They were cleaved by PIPLC, 2) after hydrolysis in 6 N HCl, both radiomethylated glucosamine and a glucosamine-inositol conjugate were identified by cation exchange chromatography, and 3) hydrolysis in 4 M trifluoroacetic acid generated a fragment consistent with glucosamine-inositol-phosphate. These results illustrate new criteria for the identification of GPIs. The labeled GPIs also contained radiomethylated ethanolamine, another component found in GPI anchors of proteins and in mature lipid precursors of GPI anchors, suggesting that the liver plasma membrane GPIs retained considerable structural homology to GPI anchors.
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PMID:Identification of glycoinositol phospholipids in rat liver by reductive radiomethylation of amines but not in H4IIE hepatoma cells or isolated hepatocytes by biosynthetic labeling with glucosamine. 132 29


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