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)

Water extraction method was applied to isolate the cell membrane from line 10 hepatoma cells and normal liver cells in strain 2 guinea pig. The materials isolated by this method were further analyzed by different immunochemical techniques including SDS-PAGE, crossed immunoelectrophoresis and crossed affino immunoelectrophoresis to demonstrate the major components and their antigenicities. Five major glycoproteins of apparent molecular weights of 44, 46, 62, 64, and 68 kDa were prominent in line 10 tumor cell materials, whereas one band of molecular weight of 82 kDa was prominent in the materials from normal liver cells. Also four minor components from line 10 tumor cells were found to be glycoprotein in nature.
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PMID:Isolation of line 10 hepatoma-cell membrane by the water extraction method and immunochemical analysis. 272 47

A high molecular weight, mucous glycoprotein (MG) from the pleural fluid of lung adenocarcinoma was purified by the DEAE-cellulose, gel-filtration and wheat germ agglutinin affinity chromatography. Protein portion of the molecule was composed of amino acids rich in serine, threonine and proline, but methionine and tyrosine concentrations were relatively low. About 65% of the weight, was composed of galactose, galactosamine, glucosamine, fucose and sialic acid. The gel-filtration pattern on Sepharose 4B revealed Mr greater than 10(6) Da. The SDS-PAGE pattern revealed a main band at the position of the Mr about 350 kDa under the reducing condition. Rabbit antibody against this molecule recognized mainly the peptide portion, and the radioimmunoassay (RIA) using the double antibody method was developed by this antibody. Serum MG level was low in healthy subjects and in benign diseases (0.8 +/- 0.7 U/ml; mean +/- SD and 1.1 +/- 2.3 U/ml, respectively). Thus, 3 U/ml was used as the cut-off value. The mean of serum MG levels and positive rates in malignant diseases were significantly high; 4.4 U/ml and 32.3% in lung cancer, 20.1 U/ml and 77.5% in pancreas cancer 11.6 U/ml and 64.3% in gastric cancer, 12.9 U/ml and 57.1% in hepatoma, 12.3 U/ml and 77.8 in colon cancer. Other malignancies such as ovarial and uterus cancer showed also high levels. Elevated values in these malignancies were observed frequently in patients with metastasis. On the other hand, the false positive cases were found in 10% of benign diseases. Determination of MG seems to be useful for the detection of several kinds of malignancies, but it is not adequately sensitive as a screening method for early cancer detection.
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PMID:Clinical significance of mucin-like high molecular weight glycoprotein originated from lung cancer as tumor marker. 274 68

The role of antibody-dependent cellular cytotoxicity (ADCC) in host defense against tumor growth and metastasis was investigated with MH134, an MM antigen-positive murine hepatoma, and MH134-M, a variant with enhanced tumorigenesis and metastasis, in syngeneic C3H/HeN mice. When inoculated subcutaneously into C3H/HeN mice, MH134-M tumors grew more rapidly than did MH134 tumors and consistently metastasized to the draining lymph nodes, whereas MH134 tumors did not. Also, MH134-M exhibited a significantly greater lung colonization potential than did MH134, when inoculated intravenously into C3H/HeN mice. In BALB/c nu/nu mice, however, solid MH134 tumors grew and metastasized to the same extent as MH134-M, indicating that there is no significant intrinsic difference between these two tumor lines in proliferative or metastatic capacity. Enzyme-linked immunosorbent assay (ELISA) and immunoblotting, performed after SDS-PAGE analysis of cellular extracts with a monoclonal antibody (MAb) that recognizes a part of the MM-antigen, revealed that the cells of MH134-M lack at least a part of the MM antigen. Sera of C3H/HeN mice bearing solid MH134 tumors were found to contain anti-MM-antigen antibodies, when tested by immunoblotting of SDS-PAGE-developed materials. Cytotoxicity testing in which thioglycollate-induced peritoneal macrophages were used as effector cells revealed that antibodies present in sera strongly induced ADCC to MH134 but not to MH134-M. On the other hand, sera of MH134-M tumor-bearing C3H/HeN mice neither contained anti-MM-antigen antibodies nor induced ADCC to MH134 or MH134-M tumor cells. Intravenous injection of carrageenan into C3H/HeN mice bearing solid MH134 tumors significantly enhanced tumor growth, whereas the growth of subcutaneously injected MH134-M tumors was not influenced by this treatment. These results suggest that the enhanced tumorigenesis and metastasis of the MH134-M line in C3H/HeN mice are based, at least in part, on significant loss of the MM antigen and the resultant inability to induce ADCC-triggering antibody production during tumor growth.
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PMID:Enhanced tumor growth and metastatic spread of an MH134 variant lacking a part of the MM antigen: a possible role of antibody-dependent cellular cytotoxicity in control of tumor growth and metastases. 274 83

The urea extract of the glycoproteins from the extracellular matrix of rat liver has been compared with that of Morris hepatoma 7777. A high molecular weight glycoprotein present in Morris hepatoma 7777 was not found in the extract of liver matrix. Under reducing conditions in SDS-gel electrophoresis this component gave two glycoprotein bands with Mr 53 k and 56 k. The indirect immunofluorescence staining with a monospecific antiserum directed against the component showed its abundant presence in Morris hepatoma 7777 as well as in the less malignant Morris hepatoma 9121 in form of extracellular network structures. The antigen also densely filled some cumuli of cells. In contrast the liver tissue showed only very weak staining of the extracellular areas. The overall distribution of the component could be correlated with the distribution of several hydrolases in the tumor matrix, notably beta-D-glucuronidase.
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PMID:Increased expression of a high molecular weight matrix component in rat hepatocellular carcinoma. 282 Sep 9

Ascitic fluid from tumour patients (hepatoma, gastric cancer, gallbladder cancer, colorectal cancer, ovarian cancer) and from non-malignant diseases (liver cirrhosis, congestive heart failure) were compared with respect to their content of determinants of the fibrinolytic system, tissue-type plasminogen activator antigen (t-PAag) and activity (t-PAact), urokinase-type plasminogen activator antigen (u-PA) and plasminogen activator inhibitor activity (PAI). Furthermore, SDS-polyacrylamide slab-gel electrophoresis (SDS-PAGE) was performed to evaluate molecular weight distribution of the detectable fibrinolytic parameters. In malignant ascites, PAI activity was three to four times higher, and increased complex formation of PAI with t-PA could be demonstrated, compared with non-malignant ascitic fluid. Tissue-type plasminogen activator antigen and activity showed a similar concentration in ascites of both study groups. Urokinase-type plasminogen activator antigen was detectable neither in ascites of malignant nor in ascites of non-malignant origin. It is concluded that t-PA is the physiological plasminogen activator in ascites and that increased PAI levels followed by increased complex formation between t-PA and PAI might reflect a reaction of the peritoneum.
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PMID:Plasminogen activators and plasminogen activator inhibitor in malignant and non-malignant ascitic fluid. 285 12

gamma-Glutamyltransferase from human hepatoma and the surrounding non-neoplastic liver tissue was purified by immunoaffinity column chromatography and characterized with regard to molecular weight, isoelectric point (pI), amino acid composition, hexosamine content and affinity for various lectins. Both enzymes showed the same molecular weight (the heavy subunit 64 000; the light subunit 26 000) and pIs (3.7-3.9) on SDS-polyacrylamide gel electrophoresis and isoelectric focusing in polyacrylamide gel, respectively. After neuraminidase treatment, the pIs for both enzymes shifted to a more alkaline pH (pI 5.7). Both enzyme preparations exhibited similar amino acid compositions; however, the glucosamine content of the hepatoma enzyme was 362 nmol/mg protein, about 3-fold higher than that of the enzyme isolated protein from the non-neoplastic tissue. Binding of the two enzymes to lectins revealed that less of the hepatoma enzyme bound to Sepharose-conjugated wheat germ agglutinin, erythroagglutinating phytohemagglutinin and Ricinus communis agglutinin. These results suggest that the two enzymes possess similar peptide moieties and degree of sialylation, but differ with respect to other aspects of their heterosaccharide moieties.
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PMID:Comparison of the peptide and saccharide moieties of gamma-glutamyltransferase isolated from neoplastic and non-neoplastic human liver tissue. 286 19

Cyclo(-Phe(p-NH[1-14C]Ac)-Thr-Lys-(CO(p-N3)C6H4)-Trp-Phe-DPro++ +), in the following named azidobenzamido-008, was synthesized in order to identify binding sites for c(Phe-Thr-Lys-Trp-Phe-DPro), named 008, (a cyclosomatostatin with retro sequence) in liver cell plasma membranes. In the dark the above photolabel was taken up into isolated hepatocytes, inhibiting the sodium dependent uptake of cholate and taurocholate in a competitive manner (Ki for cholate uptake inhibition = 1 microM; Ki for taurocholate uptake inhibition = 5 microM). When activated by flashed light the inhibition became irreversible (IC50 for cholate uptake inhibition = 2 microM; IC50 for taurocholate uptake inhibition = 9 microM) and the activated cyclopeptide bound chiefly to hepatocellular membrane proteins of 67, 54, 50, 37 kDa. Excess of the initial 008, or of cholate or phalloidin partially protected the above membrane components against labeling with 14C-labeled azidobenzamido-008. In contrast AS 30 D ascites hepatoma cells, known to be deficient in bile acid and cyclosomatostatin transport, could not be specifically labeled by azidobenzamido-008. The membrane proteins preferentially labeled in hepatocytes (50 and 54 kDa) are integral glycoproteins. The 67 kDa protein is a hydrophilic nonglycosylated membrane component. Independent of labeling with 14C-labeled azidobenzamido-008 or with 14C-labeled azidobenzamido-taurocholate, the main radioactive peaks in the pH region of 7, 5.5, 5.25 were identical after solubilization with Nonidet P-40 and subsequent isoelectric focusing. Proteins of 67, 54, 50 and 37 kDa could be enriched by use of 008-containing gels in affinity electrophoresis. Binding sites for 008 were not destroyed by SDS or Nonidet P-40 treatment of plasma membranes.
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PMID:Azidobenzamido-008, a new photosensitive substrate for the 'multispecific bile acid transporter' of hepatocytes: evidence for a common transport system for bile acids and cyclosomatostatins in basolateral membranes. 290 68

Rat liver coated vesicle preparations were frequently found to contain small ovoid bodies, which resembled coated vesicles in morphology. We have purified these bodies to homogeneity using sucrose density gradients and preparative agarose gel electrophoresis. When negatively stained and viewed by electron microscopy, the purified structures display a very distinct and complex morphology, resembling the multiple arches which form cathedral vaults. They measure 35 X 65 nm and are therefore considerably larger than ribosomes. When subjected to SDS PAGE, these structures, which we refer to as vaults, appear to contain several minor and five major species: Mr 210,000, 192,000, 104,000, 54,000, and 37,000. One of these (Mr 104,000) greatly predominates, accounting for greater than 70% of the total Coomassie Brilliant Blue-staining protein. Another major species of Mr 37,000 has been identified as a species of small RNA of unusual base composition (adenosine 12.0%, guanosine 29.7%, uridine 30.9%, and 27.4% cytidine), which migrates as a single species in urea PAGE between the 5S and 5.8S ribosomal standards, containing approximately 140 bases. Although the RNA constitutes only 4.6% of the entire structure, the large size of the particle requires that each one contains approximately 9 molecules of this RNA. Antibodies prepared against the entire particle are largely specific for the major (Mr 104,000) polypeptide species. Although they do not directly react with the RNA constituent on Western blots, these antibodies immunoprecipitate a 32P-labeled RNA of identical size from metabolically-labeled rat hepatoma cells. Vaults are observed in partially purified fractions from human fibroblasts, murine 3T3 cells, glial cells, and rabbit alveolar macrophages. It therefore appears that these novel ribonucleoprotein structures are broadly distributed among different cell types. The function of vaults is at present unknown.
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PMID:Isolation and characterization of a novel ribonucleoprotein particle: large structures contain a single species of small RNA. 294 44

A growth hormone-dependent binding protein for insulin-like growth factors (IGF-I and IGF-II) has been isolated from human plasma. Analyzed on SDS gels, the preparation contained a major protein band of 53 kDa, and a minor band of 47 kDa. After transfer to nitrocellulose, both species bound iodinated IGF-I, and could be detected using an antibody raised against the purified preparation. In contrast, an IGF binding protein purified from human amniotic fluid bound IGF-I but was not detectable immunologically. The amino acid comparison of the plasma binding protein preparation was different from that reported for amniotic fluid and HEP G2 hepatoma proteins, and the unique amino-terminal sequence, Gly-Ala-Ser-Ser-Ala-Gly-Leu-Gly-Pro-Val-, was different from that of the amniotic fluid and hepatoma proteins. This study indicates that the growth hormone-dependent IGF binding protein of human plasma is structurally and immunologically distinct from other IGF binding proteins.
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PMID:Growth hormone-dependent insulin-like growth factor (IGF) binding protein from human plasma differs from other human IGF binding proteins. 294 61

The site of synthesis of protein C inhibitor, a recently identified human plasma inhibitor against activated protein C, is not known. We have studied the production and secretion of protein C inhibitor by an established human liver cell line derived from hepatocellular carcinoma (Hep G2). The concentration of protein C inhibitor, as measured by a specific radioimmunoassay, increased in the medium of Hep G2 cells with time. There was no evidence for a significant intracellular pool of this protein. Protein C inhibitor secreted from Hep G2 cells (G2 protein C inhibitor) inhibited the activity of purified activated protein C in a functional assay. De novo synthesis of protein C inhibitor was demonstrated by the presence of specific immunoprecipitable radioactivity in the medium after 5 h of labeling of the cells with [35S]methionine. Analysis of the immunoprecipitates by SDS-polyacrylamide gel electrophoresis showed a peak of radioactivity corresponding to Mr 57 000. These results indicate that the liver is a site of protein C inhibitor production.
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PMID:Synthesis and secretion of protein C inhibitor by the human hepatoma-derived cell line, Hep G2. 298 24


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