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)

Dexamethasone and insulin stimulate production of several plasma proteins in primary cultures of adult rat hepatocytes but inhibit their production in primary cultures of Morris hepatoma cell line 7777W. The acute phase response elicited in cultured cells by crude cytokines from activated rat peritoneal macrophages is considerably higher in hepatocytes in the presence of hormones, and especially of dexamethasone. In hepatoma cells the hormones enhance the cytokine-induced formation of fibrinogen and cysteine proteinase inhibitor but are without significant effect on suppression of albumin and alpha-fetoprotein synthesis by macrophage supernatants.
Acta Biochim Pol 1988
PMID:Effects of dexamethasone and insulin on the acute phase response of Morris hepatoma cells and of rat hepatocytes in culture. 247 Feb 18

The effect of Rhizopus delemar on the carcinogenicity in rats of Aflatoxin B1 was studied. The Aflatoxin B1 was administered in free drinks to each male wistar rat at 126 micrograms per week such that a total dose of 3.40 mg was given over a period of 27 weeks. The culture abstract of Rhizopus delemar was added simultaneously to a group of these rats by mixing the Aflatoxin B1 solution. Animals were killed separately during 18th, 30th, 38th and 52nd week. Liver cell altered foci and neoplasms were qualified by using light microscopic and electromicroscopic morphology, by the morphometry and by the enzymic reactions. In the group of Aflatoxin B1 the incidence of hepatocellular carcinoma was 71%. In the group receiving Rhizopus delemar together with Aflatoxin B1, the hyperplastic foci and pathological enzymic foci were decreased at all times pointed and atd at termination, and in none of the rats had liver neoplasms appeared. The result of this experiment showed that the Rhizopus delemar has intensive capacity in inhibiting the toxic damage and carcinogenicity of the liver by the Aflatoxin B1, because it is not only able to postpone the appearance of altered foci and to control their development but also to accelerate their withdraw in advance. The Rhizopus delemar can be used as a feasible and efficacious means to control the intoxication of Aflatoxin B1.
Mater Med Pol
PMID:A study on the inhibition of aflatoxin B1 induced hepatocarcinogenesis by the Rhizopus delemar. 251 99

An in vitro transcription system was developed from H411EC3 (H4) hepatoma cells, which mimics the in vivo up-regulation by glucocorticoid hormones on ribosomal RNA (rRNA) synthesis. Ribosomal DNA (rDNA) transcription in extracts derived from H4 cells grown in the presence of 100 nM triamcinolone acetonide was 4- to 5-fold greater than that in extracts derived from cells grown in the absence of glucocorticoid. This effect was not a general stimulation by the steroid, as RNA polymerase II transcription of the metallothionein-1 gene which lacked a glucocorticoid responsive element was unaffected. The increased transcription in hormone-treated extracts was also independent of differential ribonuclease activities or inhibitors as ascertained by the inclusion of ribonuclease inhibitor and mixing experiments, respectively. Chromatography of H4 cell extracts on heparin-sepharose followed by transcription complementation analysis, showed that the hormone-induced stimulatory activity eluted with the fraction (TFIA) which contains RNA polymerase I (Pol I). Immunoblot analysis with specific anti-Pol I antibody showed similar subunit profiles in the absence and presence of the hormone. The presence of a Pol I enhancer element in addition to the rDNA promoter did not further modify the glucocorticoid-induced transcription. These results indicate that the glucocorticoid-mediated effects could be observed in cell extracts which accurately initiate transcription of cloned rat rDNA. Moreover, the alterations of rDNA transcription by the hormone is effected by a factor which elutes with fraction TFIA.
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PMID:Glucocorticoid-induced stimulation of ribosomal gene transcription in rat hepatoma cells is mediated by modification of RNA polymerase I or an associated factor. 260 60

The requirement for ATP hydrolysis in the initiation of RNA polymerase II (Pol II)-directed transcription and the relationship between ATP and novobiocin action led us to investigate whether novobiocin could inhibit transcription of the mouse metallothionein-I (MT-I) gene. Novobiocin inhibited the MT-I gene transcription in a fractionated rat hepatoma nuclear extract in a dose-dependent manner by direct interaction with a nuclear factor(s). This interaction prevented formation of stable preinitiation complexes but did not affect elongation of MT-I mRNA. Preincubation of the nuclear extract with ATP prevented the action of novobiocin on MT-I gene transcription. Although novobiocin is known to inhibit DNA topoisomerase II, VM-26, a specific inhibitor of this enzyme had no effect on the transcription. These results indicate that novobiocin blocks the Pol II-directed transcription by inhibiting formation of preinitiation complexes at an ATP-dependent step.
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PMID:Novobiocin inhibits initiation of RNA polymerase II-directed transcription of the mouse metallothionein-I gene independent of its effect on DNA topoisomerase II. 282 31

Three classes of non-histone proteins were obtained from hamster Kirkman-Robbins hepatoma and liver nuclei following separation of nucleic acids with the polyethylene glycol-dextran mixture and fractionation of nuclear proteins on hydroxylapatite in a salt-glycerol-phenylmethylsulphonyl fluoride system at increasing concentrations of Na+ and K+ phosphate buffer, pH 6.8. Two-dimensional polyacrylamide gel electrophoresis of these proteins documented their high heterogeneity; many spots were common but some spots specific only for neoplastic or normal tissue were also observed.
Acta Biochim Pol 1985
PMID:Comparison of non-histone proteins from hamster Kirkman-Robbins hepatoma and liver. 403 52

1. In a highly differentiated Morris hepatoma 5123D the fraction of repetitive, cytoplasmic poly(A)-containing RNA hybridizing with DNA to the Cot values below 10(2) mol X sec/l is present in a higher proportion than in normal rat liver. 2. Unique sequences of cytoplasmic RNA containing poly(A) both in Morris hepatoma and normal rat liver exhibit similar hybridization kinetics. 3. No sequence differences in cytoplasmic poly(A)-free RNA between Morris hepatoma 5123D and normal rat liver were found using hybridization-competition technique.
Acta Biochim Pol 1980
PMID:Comparison of cytoplasmic RNA species from rat liver and Morris hepatoma 5123D. 615 55

Activity levels of DNA-dependent RNA polymerase I (Pol I; ribonucleoside triphosphate: RNA ribonucleotidyl transferase, E.C. 2.7.7.6, eucaryotic type I) have been compared in five transplantable murine hepatomas and livers of three inbred mouse host strains. Three tumors (H6, H4 and H134) contained about 350-450 units of Pol I activity/g of tissue. Two hepatomas (H129 and BW7756) contained about 120-150 units of activity/g of tissue. Livers contained about 100-150 units/g of tissue. Chromatographic comparisons revealed that hepatoma Pol I is slightly less anionic than the liver enzyme. Thermal denaturation studies were carried out using Pol I partially purified from a high-activity line hepatoma (H6), a low-activity line hepatoma (H129) and livers of the appropriate host strains. Pol I from H6 tumors was denatured at 40 degrees C with a half-time of 2 min. The enzyme from H129 tumors and host livers was denaturated with a half-time of 7 min. These data indicate that hepatoma H6 expressed a structural variant of Pol I. This is the first Pol I variant ever reported.
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PMID:DNA-dependent RNA polymerase I from hepatomas: comparison of activity levels and properties. 724 19

Experiments were performed on rats injected with a malignant hepatoma (evoked by aflatoxin B1) or with inflammation induced by turpentine injection. On the 4th or 8th day after the injection, the following determinations were made: concentration of seromucoid, haptoglobin, sialic acid and fucose in blood serum; binding of asialo-glycoproteins by liver extracts; elimination of asialo-[125I]haptoglobin and asialo-[125I]orosomucoid from circulation. It was found that hepatoma and inflammation affected neither the activity of liver receptors for asialo-glycoproteins, nor the rate of asialo-glycoprotein elimination from circulation.
Acta Biochim Pol 1981
PMID:Catabolism of desialylated glycoproteins during carcinogenesis and inflammation in rats. 732 99

Changes in the content of N-acetylneuraminic acid in rat erythrocyte membranes at different stages of experimental tumour (Morris hepatoma 5123) development were examined. Its content was lowered on the 30th and 40th day after transplantation of the tumour cells, as compared to the results for normal healthy rats. As a result of the tumour growth, the content of N-acetylgalactosamine, galactose and mannose in rat erythrocyte membranes became lowered, whereas that of glucose remained unchanged. The content of fucose was raised at early stage of tumour growth, and remained at this high level till the 40th day of experiment.
Acta Biochim Pol 1994
PMID:The content of N-acetylneuraminic acid in glycoproteins of erythrocyte membranes in Morris hepatoma 5123 bearing rats. 803 Mar 69

Fractions A (salted out by ammonium sulphate between 21-30% saturation), and fractions B (salted out between 51-70% saturation) of pyruvate kinase (EC 2.7.1.40.) corresponding respectively to pyruvate kinase types L and M2 from rat liver and Morris hepatoma 7777 were purified by an affinity chromatography on Blue Sepharose CL-6B. Peaks of inactive proteins were eliminated and the enzyme fractions bound biospecifically to the gels were eluted by free ADP. The molecular mass of purified hepatoma pyruvate kinase fraction B was smaller than that of liver pyruvate kinase fraction B. Morris hepatoma pyruvate kinase fraction B represented a variant of type M2, characterised by greatest affinity to 2-phosphoenolpyruvate as a main substrate and different sensitivity to low-molecular effectors in comparison with types L from both liver and hepatoma and in comparison with type M2 from normal rat liver. Only this hepatoma fraction B showed a tumour specific sensitivity to L-cysteine and was insensitive to normal signal molecules i.e. to ATP and fructose-1,6-diphosphate which influence liver pyruvate kinase activity. L-Cysteine inhibited the tumour fraction B of pyruvate kinase by decreasing its Vmax and increasing the Km values in relation to 2-phosphoenolpyruvate.
Acta Biochim Pol 1993
PMID:Comparison of pyruvate kinase variants from rat liver and Morris hepatoma 7777, obtained by an affinity chromatography on blue sepharose CL-6B. 821 64


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