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)

It was found that a human hepatoma-associated ALP (orthophosphoric monoester phosphohydrolase, E.C. 3.1.3.1) shared electrophoretic mobility, inactivation by urea, inhibition by inorganic phosphate, ethylenediaminetetraacetate, and amino acids (L-phenylalanine, L-leucine and L-homoarginine), heat stability, sensitivity to neuraminidase, pH optimum, Km value, and antigen site with fast moving ALP isozymes of FL cell strain derived from human amniotic membrane. However, 40-week-old fresh amniotic membrane lacked this isozyme. Instead, it had a placental type ALP consisting of minor components. The other ALP isozyme of FL cells had properties common to hepatoma ALP with regard to L-phenylalanine sensitivity, inhibition by ethylenediaminetetraacetate, inactivation by urea, and antigen site, but differed from it in electrophoretic mobility, sensitivity to L-leucine and L-homoarginine, and the presence of another antigen site. It was more heat stable and more sensitive to inhibition by inorganic phosphate than Hepatoma AP. The possible regulatory mechanism between the hepatoma-type ALP and the placental type ALP in the amnion cells is considered.
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PMID:A hepatoma-associated alkaline phosphatase, the Kasahara isozyme, compared with one of the isozymes of FL amnion cells. 0 Sep 48

Stationary-phase, minimal deviation hepatoma H4-II-E-C3 cell cultures that are serum-deprived respond with a biphasic time course of phenylalanine hydroxylase induction when dialyzed fetal calf serum or insulin is added. These two agents induce phenylalanine hydroxylase additively, during both the initial 3-hour and the delayed 24-hour phases. The initial phase of induction by insulin is inhibited by cycloheximide but not by actinomycin D. The delayed induction by both dialyzed fetal calf serum and insulin is inhibited by 10(-6) M cycloheximide and 0.20 mug/ml actinomycin D. H4-II-E-C3 cells in culture do not synthesize the factor(s) in serum that induce phenylalanine hydroxylase.
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PMID:Control of phenylalanine hydroxylase synthesis in tissue culture by serum and insulin. 0 1

Properties of aryl hydrocarbon hydroxylase in the microsomes were compared between Morris hepatoma 5123D and the host liver from rats bearing this tumor. Requirement of NADPH for the assay of the enzyme activity was observed, compared to that of NADH, and also the additive effect of NADH on the requirement of NADPH was found in the tumor and liver. Curve of pH optimum of the enzyme activity in tumor and liver differed between the rats treated with corn oil and those with 3-methylcholanthrene, indicating a slight shift of the peak value to alkaline pH in the latter. The same values of the apparent Km for NADPH and NADH were shown for the enzyme from the liver and tumor even 24 hr after the treatment with 3-methylcholanthrene, but a difference in the apparent Km for benzo[a]pyrene was demonstrated between the tumor and the host liver, showing 3.6 approximately 6.6 muM in the former and 9.1 approximately 20 muM in the latter. By the addition of 7,8- or 5,6-benzoflavone to the assay medium for the tumor, the induced enzyme was inhibited noncompetitively, and the constitutive enzyme was enhanced, as demonstrated in the host liver. As observed in the induced enzyme in both tissues, cyclohexene oxide and 1,1,1-trichloropropane oxide slightly increased the activity of the constitutive enzyme in the tumor, in contrast to its inhibition in the host liver.
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PMID:Properties of aryl hydrocarbon hydroxylase in microsomes of Morris hepatoma 5123D and the host liver. 0 50

The specificity of lactoperoxidase-catalyzed iodination for the proteins of the hepatoma tissue culture cell plasma membrane was examined by histochemical, biochemical, and cell fractionation techniques. Light microscope autoradiography of sectioned cells shows the incorporated label to be localized primarily at the periphery of the cell. Most of this label can be released from the cell by trypsin but not by collagenase or hyaluronidase. The label is recovered from the cells as either monoiodotyrosine or diiodotyrosine after hydrolysis of cell extracts with a mixture of proteolytic enzymes. The label co-purifies during cell fractionation with an authentic liver cell plasma membrane marker enzyme, 5'-nucleotidase. Thus, the incorporated iodide is itself a valid marker for those membrane polypeptides having tyrosine residues accessible to the lactoperoxidase. The polypeptide complexity of the purified plasma membrane was examined by high resolution dodecyl sulfate-polyacrylamide gel electrophoresis. At least 50 polypeptides in the membrane are accessible to iodination. These polypeptides probably represent the bulk of the protein mass of the membrane and iodinating them does not affect cell viability, growth rate, or cell function. Labeling experiments with fucose and glucosamine show that at least nine of the iodinated peptides may be glycoproteins.
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PMID:Proteins of the hepatoma tissue culture cell plasma membrane. 0 57

Rodent cells were found to contain a high level of alcohol dehydrogenase activity which was not inducible. Other hepatoma and nonhepatoma cell lines were tested and found to contain lower but measurable levels of alcohol dehydrogenase.
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PMID:Viability of cells in ethanol. Role of alcohol dehydrogenase. 0 66

Distribution of transglutaminase activity was determined in normal rat liver, a 3'-methyl-4-dimethylaminoazobenzene-induced primary hepatoma, and the Novikoff hepatoma. Over 90% of the total enzyme activity was found in the 105,000 X g supernatant of normal liver, whereas only 30% was found in this fraction of the hepatomas, the remainder being found in the particulate fraction. The is distribution pattern did not correlate with protein distribution nor did it change during cellular proliferation, since regenerating liver and embryonic tissue had the same pattern as normal liver. Cell protein was a suitable acceptor substrate for the enzyme. Kinetic analyses showed that liver and hepatoma enzymes had a similar Km and Vmax for putrescine incorporation into cell protein. Hepatoma particulate enzyme was more stable than either liver or hepatoma supernatant enzyme. The enzyme may also act as the acceptor molecule.
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PMID:Differential transglutaminase distribution in normal rat liver and rat hepatoma. 0 47

DNA polymerase [EC 2.7.7.7] activities present in hypotonic extract from rat ascites hepatoma AH130 cells were eluted in three separable peaks on DEAE-cellulose column chromatography. Peak I activity had an alkaline pH optimum, and was relatively resistant to SH-blocking reagents and salt concentration. These properties of DEAE peak I are typical of low molecular weight DNA polymerase. DEAE peak II and peak III activities possessed properties corresponding to high molecular weight (6-8 S) polymerase; they showed maximal activity at neutral pH, and were sensitive to SH-blocking reagents and salt. No low molecular weight polymerase activity was released from DEAE peak II or peak III by salt treatment, though partial conversion from DEAE peak II to peak III was observed on the same treatment.
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PMID:Studies on the molecular species of DNA polymerase extracted from rat ascites hepatoma cells. 0 55

Effects of glutamine on glutamine synthetase (GS) activity of hepatoma tissue culture (HTC) cells were studied with the aid of a specific goat anti-rat GS serum. Immunodiffusion and immunoelectrophoretic tests show that rat liver GS and HTC cell GS are immunologically similar but not identical. Immunotitrations of HTC cell extracts demonstrate that in cells incubated in high concentrations (5 mM) of glutamine, a cross-reacting form of GS with a decreased enzyme-specific activity accumulates. On prolonged incubation of cells in high glutamine, there is net degradation of GS to form immunologically inactive products. Radio-immunoprecipitation experiments show that glutamine acts by accelerating the degradation of preformed GS.
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PMID:Glutamine-stimulated modification and degradation of glutamine synthetase in hepatoma tissue culture cells. 0 12

The gamma-glutamyltransferase (EC 2.3.2.2) (=gamma-glutamyltranspeptidase, gamma-GTP) activity in hepatoma induced by 3'-methyl-4-(dimethylamino)azobenzene (3'-Me-DAB) was 120-fold higher than that of normal liver and high activity was also found in bovine hepatocellular carcinoma. gamma-GTPs from these malignant tissues responded more and showed broader specificity to gamma-glutamyl group acceptors than those from normal tissue such as bovine, rat, and mouse liver and bovine kidney. Three species of gamma-GTP were isolated from bovine kidney by DEAE-cellulose chromatography, whereas only two species were isolated from bovine hepatocellular carcinoma. The carcinoma lacked the least acidic enzyme species. Appropriate gamma-glutamyl group acceptors stimulated more-acidic enzyme species more than less-acidic species in both tissues. The fractions separated from the hepatoma were stimulated more than those of kidney by gamma-glutamyl group acceptor. The enzymes from normal tissues responded similarly to a gamma-glutamyl group acceptor irrespective of the difference in their activity. Thus, gamma-GTPs of malignant tissues appear to be more versatile for amino acid transport, both qualitatively and quantitatively. In these properties the enzyme of mouse fetal liver which showed the highest activity in the last period of pregnancy resembled the enzymes of malignant rather than normal tissues. The activity of hepatic gamma-GTP is not parallel with the rate of cell proliferation during normal development.
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PMID:Higher transpeptidation activity and broad acceptor specificity of gamma-glutamyltransferases of tumors. 0 27

Unlike other beta-class eukaryotic DNA polymerases, the enzyme purified from the Novikoff hepatoma is inhibited by both sulfhydryl blocking agents N-ethylmaleimide (NEM) and p-hydroxymercuribenzoate (pHMB). The degree of sensitivity varies depending on the enzyme purity, pH of the reaction, and the presence of sulfhydryl reducing agents. Novikoff beta-polymerase activity is unaffected by the presence of 2-mercaptoethanol (2-Me) or dithiothreitol (DTT); however, the combination of 2-mercaptoethanol and NEM or pHMB acts to reverse the inhibition of the sulfhydryl blocking agent. The reversal of inhibition involves more than just a titration of NEM with 2-mercaptoethanol since a) the combination of these two reagents actually stimulates the DNA polymerase, and b) dithiothreitol did not reverse the inhibition. Binding of the polymerase to DNA did not affect the enzyme sensitivity to NEM.
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PMID:Novikoff hepatoma deoxyribonucleic acid polymerase. Sensitivity of the beta-polymerase to sulfhydryl blocking agents. 0 24


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