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)

Wheat germ agglutinin binding to a rat hepatoma cell line dRLa 74 treated with concanavalin A was studied. It increased depending on the concanavalin A concentration in the culture medium. The cells exhibited about twofold increase in wheat germ agglutinin-binding when pretreated with 50 micrograms/ml of concanavalin A for 48 h. The wheat germ agglutinin binding sites were shown to be localized at the cell surface by lectin-histochemistry. Wheat germ agglutinin blotting of microsomal membrane proteins showed a broad wheat germ agglutinin-reactive band with an apparent molecular weight of 90 to 100 kDa. Loss of wheat germ agglutinin binding to dRLa 74 cells and the glycoprotein after neuraminidase treatment suggested that wheat germ agglutinin reacted with cell surface sialyl residues of dRLa 74 cells. The induced change was reversible. Increased wheat germ agglutinin binding returned to the pretreatment level when the concanavalin A-treated cells were subcultured in the absence of concanavalin A. These observations suggest that environmental factors interacting with tumor cell surface sugar moieties may induce reversible epigenetic changes on cell surface carbohydrate structures.
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PMID:Increase in cell surface wheat germ agglutinin binding in a rat hepatoma cell line dRLa 74 treated with concanavalin A. 196 34

Rat liver particulate fraction contains two types of membrane-associated and gangliosides-hydrolyzing sialidase, which have been shown to be identical to two membrane-associated sialidases of rat brain (I and II) chromatographically, immunologically and in substrate specificity. Chromatography on AH-Sepharose 4B of the membrane sialidases of rat primary hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (MeDAB) further revealed that hepatocarcinogenesis induces a marked decrease in sialidase II but no decrease in sialidase I. Using antisera against sialidases I and II of rat brain, immunoprecipitation studies of the solubilized particulate fractions of rat liver and MeDAB-hepatoma gave results similar to those obtained chromatographically. Using the same immunological technique, sialidase II but not sialidase I was found to be decreased in AH109 A hepatoma and in regenerating and fetal liver.
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PMID:Neoplastic alteration of a membrane-associated sialidase of rat liver. 212 93

Gangliosides of hepatomas have been analyzed by using a monoclonal antibody directed to N-acetylneuraminosyl(alpha 2-6)lactoneotetraosylceramide (sialyl(alpha 2-6)paragloboside), which was prepared by injecting the monosialoganglioside fraction of human meconium into BALB/c mice. The monoclonal antibody, named MSG-15, was found to bind sialyl(alpha 2-6)paragloboside, but it failed to react with other gangliosides, including N-acetylneuraminosyl(alpha 2-3)lactoneotetraosylceramide (sialyl (alpha 2-3)paragloboside) and "Ii"-type gangliosides. MSG-15 was found to recognize NeuAc alpha 2-6Gal beta structure of the ganglioside. Gangliosides obtained from human hepatomas were analyzed by immunostaining on high-performance thin-layer chromatography plates using the monoclonal antibody MSG-15. All primary hepatoma samples used in this study (nine samples) were found to contain sialyl(alpha 2-6)paragloboside, which accounted for 13-31% of the monosialoganglioside fractions in the hepatomas. Furthermore, MSG-15 recognized several monosialogangliosides in addition to sialyl(alpha 2-6)paragloboside. These gangliosides apparently also contain a terminal NeuAc alpha 2-6Gal beta structure. Other ganglioside fractions obtained from hepatoma and meconium were immunostained on thin layer chromatography plates with MSG-15. Additionally, another monoclonal antibody (H-11), which recognizes terminal lactosamine structure, was used to immunostain these fractions after sialidase treatment. Bands stained with both monoclonal antibodies showed similar mobilities to each other in the di- and trisialoganglioside fractions as well as monosialoganglioside fraction. In control liver, GM3 ganglioside accounted for 92% of monosialoganglioside fraction, and sialyl(alpha 2-6)paragloboside accounted for less than 1% of the fraction. Immunohistochemical study by using MSG-15 in tissue sections from hepatocellular carcinoma and normal liver tissues demonstrated that only hepatocellular carcinoma cells gave a positive reaction. These results suggest that the biosynthetic pathway of gangliosides containing NeuAc alpha 2-6Gal beta 1-4GlcNAc beta structure is activated in hepatoma cells.
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PMID:Accumulation of gangliosides with N-acetylneuraminosyl(alpha 2-6)lactosamine structure in primary human hepatoma. 215 56

Listeria monocytogenes was examined for the presence of surface carbohydrates to ascertain whether surface sugars, if present, would interact with eucaryotic surface carbohydrate receptors. We found that a virulent, but not two avirulent strains had a surface alpha-D-galactose residue as determined by agglutination with Griffonia simplicifolia (GS-I) and other lectins. The virulent strain bound to a human hepatocarcinoma cell line (HepG2), which has a well characterized receptor for alpha-D-galactose. This interaction could be blocked by pretreatment of the HepG2 cells with either alpha-D-galactose or neuraminidase, the latter of which will render the galactose receptor functionally inactive. We propose that the attachment of the virulent Listeria to eucaryotic cells occurs as a result of the interaction of the microbial alpha-D-galactose with that of the eucaryotic galactose receptor. This surface carbohydrate may provide an explanation for the mechanism of attachment and penetration of virulent Listeria into host cells during infection. As such, this may allow for amplification of pathogenesis through intracellular multiplication in nonprofessional phagocytes prior to macrophage involvement.
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PMID:Adherence of a virulent strain of Listeria monocytogenes to the surface of a hepatocarcinoma cell line via lectin-substrate interaction. 215 70

Previous work has shown that low-density lipoproteins (LDL) secreted by hepatoma-derived cell lines have an unusual composition compared to plasma LDL; rather than cholesteryl ester, the hepatoma cell-secreted LDL have a triacylglycerol core. We have found that they also have an increased negative charge, as judged by agarose electrophoresis. Since apolipoprotein B is a glycoprotein containing carbohydrate chains terminated with negatively charged sialic acid residues, we examined whether increased glycosylation of the apolipoprotein B from three hepatoma cell lines (Hep G2, Hep 3B and Huh 7) might account for the differences in LDL charge. The weight percent carbohydrate for Hep G2, Hep 3B and Huh 7 LDL-protein (1.1 +/- 0.2; 1.7 +/- 0.8; 0.4 +/- 0.1) was found to be extremely low compared with the 2.8-9% range we found for plasma LDL-protein, while the amount of LDL-lipid associated carbohydrate from hepatoma LDL was similar to that we found in plasma LDL. Furthermore, desialation of hepatoma cell-secreted LDL with neuraminidase did not normalize the negative charge to that of neuraminidase-treated plasma LDL. Western blots of thrombin proteolytic fragments indicated that, in addition to the T1-T4 fragments seen in plasma apolipoprotein B, apolipoprotein B of hepatoma-derived LDL produced four to five new fragments (T5-T9), suggesting increased exposure of proteolytic sites. Western blotting of the new fragments with antibodies specific for known apolipoprotein B sequences suggests that many of the new cleavage sites cluster in or near the putative LDL receptor recognition site.
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PMID:Unique structural properties of apolipoprotein B in low-density lipoproteins produced by several human hepatoma-derived cell lines. 217 71

Four murine MoAbs, KM191(IgM), KM206(IgM), KM230(IgG1) and KM231(IgG1), against human gastric cancer were generated using mice which underwent tolerance treatment to stomach tissues. They exhibited very similar high reactivities to stomach adenocarcinoma cells and low reactivities to normal cells in both membrane binding assay and immunohistochemical analysis. Their antigens were neuraminidase and protease sensitive and existed as macromolecules (1,000Kd) in body fluids. Binding of each antibody was inhibited by the others and KM231 showed the highest binding avidity. When they were used to detect the antigens shed in ascitic fluids and pleural effusions of cancer patients, KM231 allowed the most efficient detection of the antigen. The above results indicated that the four MoAbs bound to closely related epitopes on the same antigen and that the nature of its high binding avidity enabled KM231 to show the greatest efficiency in the detection of the antigen in body fluids. KM231 was applied to serum diagnosis and gave high positive percentages in pancreatic cancer(86%), hepatocarcinoma(87%), gall bladder cancer(50%), and gastric cancer(34%), whereas in healthy persons (0%) and benign diseases except for hepatitis(29%) the percentages were low. KM231 was similar to NS19-9, but quite different from NS19-9 in the high positive percentages of hepatocarcinoma in serum diagnosis.
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PMID:Comparative studies on monoclonal antibodies raised against human gastric cancer for application to serum diagnosis of cancer. 245 69

An antibody-lectin enzyme immunoassay (EIA) technique was developed for the analysis of sugar chains of serum alpha-fetoprotein in various liver diseases. The anti-'alpha-fetoprotein'-IgG was coated on a microtiter plate and then treated with periodic acid. A serum sample was added to the plate and then a 'peroxidase'-conjugated lectin was added. The amount of lectin bound to the sugar chain of the 'alpha-fetoprotein' was estimated from the 'peroxidase' activity. The 'peroxidase' activities of 4 different lectins, LCA, Con A, LCA and EPHA, were compared. The LCA/'wheat germ agglutinin' activity ratio and LCA/EPHA activity ratio were increased in liver diseases and LCA/'wheat germ agglutinin' ratio showed a statistically significant difference between the chronic hepatitis and the liver cirrhosis groups (p less than 0.05). Furthermore, when serum samples were pretreated with sialidase, a statistically significant difference was observed in the LCA/EPHA and LCA/Con A ratios between the chronic hepatitis and the hepatoma groups (p less than 0.05). These results indicated that low sialylation at the non-reduced end of the sugar chains of 'alpha-fetoprotein' occurs in liver cirrhosis and that high fucosylation at the reduced end of N-acetylglucosamine residue of 'alpha-fetoprotein' occurs in hepatomas.
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PMID:Alpha-fetoprotein antibody-lectin enzyme immunoassay to characterize sugar chains for the study of liver diseases. 246 50

The lectin from the elderberry (Sambucus nigra L.) bark, shown to recognize the sequence neuraminic acid (alpha 2,6) galactose/N-acetylgalactosamine, was applied for detecting binding sites in Lowicryl K4M sections by light and electron microscopy. The lectin was used either directly complexed to colloidal gold or in a two-step cytochemical affinity technique. The lectin-gold complex proved to be superior and thus was extensively tested on rat liver, kidney and hepatoma cells as well as on sheep and bovine submandibular glands. Controls to establish specificity of lectin-gold binding included sugar and glycoprotein inhibition tests and enzymic removal of sialic acid. In agreement with biochemical data demonstrating the potentiating effect of sialic acid on the binding of the lectin to oligosaccharides, enzymic removal of sialic acid from liver sections resulted in abolition of lectin staining. However, in the submandibular glands, neuraminidase pretreatment of the sections had no effect on the subsequent lectin-gold binding. In rat kidney some structures became negative while others retained the lectin-gold staining due to binding to penultimate N-acetylgalactosamine exposed after sialic acid removal. In line with this, spot blot analysis demonstrated that the lectin-gold complex reacted with both fetuin and asialofetuin. Taken together, these results suggest that, for cytochemical staining, the sialic acid and the galactose/N-acetylgalactosamine lectin combining subsites of Sambucus nigra L. lectin are equally reactive with cellular glycoconjugates and that neuraminidase predigestion of tissue sections is of utmost importance to ensure specificity of staining for the sequence neuraminic acid (alpha 2,6) galactose/N-acetylgalactosamine.
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PMID:Elderberry bark lectin--gold techniques for the detection of Neu5Ac (alpha 2,6) Gal/GalNAc sequences: applications and limitations. 246 94

Biochemical characteristics of alpha-L-fucosidase (alpha-L-fucoside hydrolase, EC 3.2.1.51) were studied in tumorous and nontumorous human hepatocellular carcinoma (n = 14). Five parameters were studied: (i) specific activity, (ii) thermostability, (iii) enzyme affinity for an artificial substrate (Km), (iv) isoenzyme patterns of the glycosidase before and after neuraminidase treatment and (v) pH influence on enzyme activity. The specific activity of alpha-L-fucosidase was significantly decreased in tumoral liver when compared to nontumoral liver. The curve of pH activity constantly showed a broad optimum centered near pH 5, whereas two optima were always observed in nontumoral areas. In contrast, there was no modification of the thermostability, the substrate affinity and the isoenzyme patterns of alpha-L-fucosidase in hepatocellular carcinoma.
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PMID:Biochemical aspects of alpha-L-fucosidase in hepatocellular carcinoma. 253 49

Intracellular movement of cell surface 5'-nucleotidase was studied in H4S cells, a rat hepatoma cell line. Surface labelled cells were incubated for various periods at 37 degrees C and treated with neuraminidase at 0 degrees C. Removal of sialic acid residues from glycoproteins results in a change of their isoelectric points. Analysis with isoelectric focusing was then used to distinguish between cell surface and intracellular 5'-nucleotidase. Incubation of 125I-surface-labelled cells at 37 degrees C resulted in a gradual decrease of labelled 5'-nucleotidase at the plasma membrane until, at 60 to 90 min, a steady state was reached with 52% of the label on the cell surface and 48% intracellular. Pretreatment of the cells with the weak base primaquine had no influence on this distribution while at the same time uptake of iron via the transferrin receptor was inhibited. Using immunoelectron microscopy 5'-nucleotidase was found on the cell surface, in multivesicular endosomes and the Golgi complex. Preincubation of the cells in the presence of cycloheximide caused a reduction of labelling in the Golgi complex, whereas the label in the other compartments was retained. These results lead to the conclusion that 5'-nucleotidase does not recycle through the Golgi complex and that in contrast to the transferrin receptor the recycling of 5'-nucleotidase is not inhibited by primaquine.
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PMID:Recycling of 5'-nucleotidase in a rat hepatoma cell line. 285 Jan 62


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