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)

A membrane filter procedure developed by Igarashi et al. (1984) for the measurement of glucose 6-phosphate uptake by the microsomes has been demonstrated to be a good method for assaying glucose-6-phosphate translocase, an obligatory component of the microsomal glucose-6-phosphatase system. When glucose-6-phosphate translocase was assayed in developing and diabetic rat livers independently of hexose-6-phosphate phosphohydrolase, another obligatory component of the glucose-6-phosphatase system, the two activities were found to undergo alterations, whose profiles, however, were quite distinct from each other. The profile of the microsomal glucose-6-phosphatase activity resembles the profile of the phosphohydrolase activity rather than that of the translocase activity, suggesting that the phosphohydrolase may be rate-limiting at least under these conditions. AH-109A, a strain of transplantable rat ascites hepatoma, was found to lack both glucose-6-phosphate translocase and hexose-6-phosphate phosphohydrolase activities.
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PMID:Analysis of glucose-6-phosphate translocase and hexose-6-phosphate phosphohydrolase, the two obligatory components of microsomal glucose-6-phosphatase system, in rat liver. 285 Jun 43

The histochemical characteristics of liver cell foci in woodchucks were investigated. The foci appeared to be distributed throughout the liver and were observed only in the woodchuck hepatitis virus (WHV)-positive animals, including all 19 woodchucks with hepatocellular carcinoma(HCC), and 7 without HCC. No foci appeared in 11 WHV-negative animals. Histochemical studies revealed that liver cell foci and carcinoma cells were characterized by positive gamma-glutamyl transpeptidase (GGT) enzymatic reactions and decreased glucose-6-phosphatase enzyme activity compared to non-neoplastic liver. Furthermore, serum GGT was significantly elevated in almost all of the animals which had larger carcinomas. Ultrastructural findings of foci showed some resemblance to carcinoma cells, being characterized by abundant free ribosomes within the cytoplasm and undeveloped endoplasmic reticulum. These results suggest that the liver cell foci are potential precursors of HCC in WHV-infected animals, and that serum GGT may be a useful marker for indicating the development of carcinoma.
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PMID:Enzyme-altered liver cell foci in woodchucks infected with woodchuck hepatitis virus. 289 65

Three enzyme makers, glucose-6-phosphatase, ATPase and gamma-glutamyl transpeptidase, have been used in studying carcinogenesis of hepatocellular carcinoma. They have been investigated in animal models and human hepatocellular carcinoma in vivo and in vitro. But the inconsistent levels of these three enzymes associated with this type of carcinoma raised the possibility that the carcinoma cells might have derived from the cells originating from different stages of differentiation. To evaluate this possibility, three human cell lines, Hep G2, Hep 3B, and HA 22T, all thought to be arrested in different stages of differentiation based on their biochemical and morphological characteristics, were used as models. The three enzyme markers glucose-6-phosphatase, ATPase and gamma-glutamyl transpeptidase were examined cytochemically and biochemically. Our results showed that there was no correlation between the ATPase levels and the stages of the cell line's differentiation. But both glucose-6-phosphatase and gamma-glutamyl-transpeptidase were higher in cells that were more differentiated.
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PMID:Cytochemical localization and biochemical analysis of the enzyme markers in human hepatoma cell lines. 290 58

A hepatocellular carcinoma cell line, LMH, has been established from a hepatocellular carcinoma induced in a male leghorn chicken by diethylnitrosamine. The cell line is characterized by well-differentiated morphological and biochemical features including the expression of glucose-6-phosphatase and canalicular ATPase activities and triploid karyotype with six marker chromosomes. The cells have been continuously propagated in culture for 5 yr and are now at about the 120th passage. Morphological change occurred in culture associated with gradual increase in growth rate at about the 40th passage. However, the biochemical and chromosomal features remained constant. This is the first established domestic fowl epithelial cell line and will allow comparative investigation of a number of parameters relevant to chicken hepatocarcinogenesis.
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PMID:Establishment and characterization of a chicken hepatocellular carcinoma cell line, LMH. 360 75

Activities of glucose-6-phosphatase, fructose 1,6-diphosphatase, ornithine transcarbamylase, arginase and xanthine oxidase were measured in thioacetamide induced primary hepatoma and its tumour cell suspension. It was observed that the percentage decrease in the activities of all the enzymes in tumour cell suspension was far more than that observed in tumour tissue. However, in these studies no qualitative difference was observed between the parenchymal cells and the tumour cells.
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PMID:Enzyme studies on tumour cell suspensions. 432 28

A human hepatocellular carcinoma cell line (FOCUS--Friendship of China and United States) was derived from a patient with primary hepatocellular carcinoma. This cell line has been in continuous culture over an 18-mo period. The morphological and ultrastructural features of FOCUS are consistent with its neoplastic hepatocellular origin. FOCUS cells contain aspartate aminotransferase and glucose-6-phosphatase activity. In addition, alpha 1-antitrypsin, fibrinogen, alpha fetoprotein, and carcinoembryonic antigens were detectable in the cytoplasm of the cultured cells by immunochemical staining techniques. The karyotype of the FOCUS cell is human in origin and its contains human DNA sequences as detected by molecular hybridization analysis. The FOCUS cells do not show evidence of density-dependent inhibition of growth under confluent conditions. Repeated growth curves over an 18-mo period were identical, revealing a doubling time of 42 to 48 h. The malignant potential of FOCUS cells was further demonstrated by their ability to lead to gross tumor formation after subcutaneous injection into nude mice. From one of the solid tumors grown in nude mice, recultured cell lines have been established and found to have properties identical to the original FOCUS cell line. This FOCUS cell line represents an additional model for further investigation of tumor specific antigens and the relationship between hepatitis B virus (HBV) and hepatocellular carcinoma. Preliminary molecular characterization has indicated the existence of integrated HBV sequences within the FOCUS genome.
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PMID:Establishment and characterization of a new human hepatocellular carcinoma cell line. 608 98

An enzyme histochemical study was performed to investigate abnormal enzyme activity in human hepatocellular carcinoma (HCC) and, by application of these staining reactions to noncancerous liver disorders, to clarify the true nature of putative percancerous lesions. The enzyme activity of hepatocytes in cirrhotic livers, hepatitis B virus (HBV)-positive cells, and dysplastic liver cells was investigated. Although the tumor cells in HCC gave an intensively positive reaction for gamma-glutamyl transpeptidase activity at the cytoplasm and the whole-cell membrane, they were essentially deficient in glucose-6-phosphatase, alkaline phosphatase, acid phosphatase, and nonspecific esterase activities. Cirrhotic liver showed loss of the orderly zonal difference of enzyme activity that is present in normal liver. However, a pattern of enzyme deviation similar to that of HCC was not recognized anywhere. Neither HBV-positive hepatocytes nor dysplastic liver cells were shown enzymatically to be direct precusors of HCC.
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PMID:Human hepatocellular carcinoma and putative precancerous disorders: their enzyme histochemical study. 611 3

The change in the activity of several hepatic enzymes during hepatocarcinogenesis suggests a pattern of dedifferentiation. This category of enzymes includes glucose-6-phosphatase and gamma-glutamyltranspeptidase (GGT). A detailed kinetic analysis of microsomal glucose-6-phosphatase activity revealed that both the translocase and phosphohydrolase activities were markedly reduced in Morris 7777 hepatoma transplanted in male Buffalo rats. In addition, the activity of the translocase component increased 2.4-fold, while the phosphohydrolase activity decreased 1.6-fold in the liver of tumor-bearing animals. GGT activity in the host liver was not effected by the presence of the tumor. These results suggest differences in the effect of Morris 7777 hepatoma on: the phosphohydrolase and translocase activities of microsomal glucose-6-phosphatase and the sensitivity of glucose-6-phosphatase and GGT activities in the host liver.
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PMID:Effect of Morris 7777 hepatoma on microsomal glucose-6-phosphatase latent activity. 614 32

PLC/PRF/5, a tissue culture cell line derived from a human hepatocellular carcinoma and producing hepatitis B surface antigen (HBsAg), was studied by immune and enzyme histochemical techniques. HBsAg was demonstrated in the cytoplasm and on the surface of tumor cells. The percentage of HBsAg-positive cells in subculture increased with time until almost all cells expressed HBsAg when the monolayer reached confluence. Similar patterns were found for alpha 1-anti-trypsin and carcino-embryonic antigen, whereas alpha-fetoprotein was observed only in small foci of cells. Hepatitis B core antigen and albumin were not detected. gamma-Glutamyl transferase activity was markedly increased in the tumor cells, whereas adenosine triphosphatase and glucose-6-phosphatase activities were not demonstrable. Patterns of antigenic expression and enzyme phenotype of PLC/PRF/5 cells show remarkable resemblance to those observed in vivo in human hepatocellular carcinoma. Therefore, this cell line may be a useful model to study the control and modulation of both oncofetal antigens and HBsAg.
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PMID:Immune and enzyme histochemical studies of a human hepatocellular carcinoma cell line producing hepatitis B surface antigen. 616 57

Key enzymes of gluconeogenesis in the liver, phosphoenolpyruvate carboxykinase [EC 4.1.1.32] and glucose-6-phosphatase [EC 3.1.3.9], were studied in patients with primary or metastatic hepatic cancer. Liver specimens for enzyme assay were obtained by necropsy performed within four hours after death. It was confirmed that both enzyme activities in rat liver preserved at 4 degrees C remained unchanged within nine hours after the removal of the tissue. Activities of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase decreased to below ten per cent of the control in neoplastic liver tissue of patients with hepatocellular carcinoma accompanied with liver cirrhosis. These two enzyme activities in cirrhotic tissue of patients with hepatocellular carcinoma were lower than those in patients merely with cirrhosis. In patients with metastatic hepatic cancer both two enzyme activities further decreased and were scarcely detected not only in neoplastic tissue but also in non-neoplastic tissue. These results show that hepatic gluconeogenesis markedly decreases in patients with primary or metastatic hepatic cancer. The biochemical analysis of the blood in hepatic cancer, decreased in blood glucose and release in immunoreactive glucagon, also suggested the suppression of gluconeogenesis.
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PMID:Hepatic gluconeogenic key enzymes in patients with hepatic cancer. 625 51


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