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)

The guanine insertion enzyme from Escherichia coli catalyzes exchange of guanine located at the first position of the anticodon of tRNA with radioactive guanine (N. Okada and S. Nishimura, unpublished data). tRNA isolated from various tumors, including slowly growing Morris hepatoma 7794A, incorporated considerable guanine with E. coli guanine insertion enzyme, whereas tRNA isolated from all normal tissues so far tested, except regenerating rat liver, incorporated scarcely any. In the rat ascites hepatoma AH7974, the guanine was mostly incorporated into minor isoaccepting species of tRNAAsp that contained the guanine residue instead of Q base in the first position of the anticodon. This is a sensitive and easy method for identifying unique tRNA species in tumor tissues.
Proc Natl Acad Sci U S A 1978 Sep
PMID:Detection of unique tRNA species in tumor tissues by Escherichia coli guanine insertion enzyme. 36 Feb 13

BCG cell wall skeletons (SK) derived from BCG cell walls (CW) by treatment with proteolytic enzymes and organic solvents were tested for their potency to cause regression of a transplanted guinea pig hepatoma. On a weight basic, SK were as effective as CW in causing tumor regression, and they, as well as purified protein derivative of mycobacteria, provoked delayed cutaneous hypersensitivity reactions in animals immunized with CW or with SK. On a weight basis, CW were more active than SK in eliciting delayed cutaneous hypersensitivity in sensitized guinea pigs whether the animals were immunized with CW or with SK. In unimmunized animals the inflammatory response to intradermally administered CW was greater than that evoked by SK. CW and SK provoked delayed cutaneous hypersensitivity reactions of similar strength in animals immunized with living BCG. This study provided no compelling reasons for using SK instead of CW in clinical trials of cancer treatment by mycobacterial vaccines.
Infect Immun 1978 Sep
PMID:Immunotherapy of a guinea pig hepatoma with mycobacterial vaccines: comparison of BCG cell walls and cell wall skeletons. 36 72

Heat-killed whole BCG cells (KC) and BCG cell walls (CW) were each tested in emulsified form for their potency to cause regression of a transplanted guinea pig hepatoma. On a weight basis, KC were at least as effective as CW in causing tumor regression and elimination of microscopic lymph node metastasis, and they, as well as purified protein derivative of mycobacteria, provoked delayed cutaneous hypersensitivity reactions in animals immunized with CW or with KC. On a weight basis, KC were as active as CW in eliciting delayed cutaneous hypersensitivity in sensitized guinea pigs whether the animals were immunized with CW or with KC. In unimmunized animals the inflammatory response to intradermally administered KC was similar to that induced by CW. Because KC are easier to prepare than CW, it is suggested that whole killed BCG might be used instead of CW in clinical trials of cancer treatment requiring administration of nonliving mycobacteria.
Infect Immun 1979 Sep
PMID:Immunotherapy of guinea pigs with a transplanted hepatoma: comparison of intralesionally administered killed BCG cells and BCG cell walls. 38 92

The growth rate of Morris Hepatoma No. 44 (generation time, 6 mo) was inhibited after the induction of hypothyroidism by Propylthiouracil (PTU) (0.1% in Purina Chow), I131 (1 mCi/100 g body wt i.p.), or surgical thyroidectomy. After 11 wk of treatment, hepatoma weight was 66%, 87%, and 75% (after correction for total body wt) relative to controls in PTU-fed, I131 injected, and thyroidectomized rats, respectively. In each case, exogenous thyroxine (T4) (8 microgram/kg body wt i.p.) reversed these inhibitory effects, while T4 administered to euthyroid rats stimulated hepatoma growth. The degree of growth-inhibition achieved with PTU was not observed in pair-fed rats. In addition, after correction for differences in body weight, the sex of the tumor-bearing rats did not influence the response to PTU. Pretreatment with PTU for 2 wk before implantation did not give any added advantage over the effects of PTU administered approximately 10 days after implantation. Serum levels of triiodothyronine (T3) and T4, as well as the concentration of various biochemic parameters, were determined at the time of death. These results suggest that the growth rate of Morris Hepatoma No. 44 is thyroid hormone dependent.
Gastroenterology 1979 Sep
PMID:Inhibition of the growth of Morris hepatoma No. 44 in rats after induction of hypothyroidism: evidence that Morris hepatomas are thyroid dependent. 45 48

The possibility that carcinogens may affect methylase-mediated methylation of replicating DNA was investigated. A system eminently suitable for this purpose is liver regenerating after partial hepatectomy, as one injection of dimethylnitrosamine (DMN) given during the ensuing period of increased DNA synthesis induces hepatocellular carcinoma. Methylation of DNA by DNA methylase normally occurs only in proportion to DNA synthesis. Therefore simultaneous measurements were made of synthesis (incorporation of [14C]adenine into DNA adenine, or of d[5-3H]cytidine into DNA cytosine), and of methylation (incorporation of [methyl-3H]methionine into 5-methylcytosine of DNA) in liver regenerating after partial hepatectomy. After treatment with DMN, the ratio of methylation: synthesis remained within the normal range. Methyl methanesulphonate (MMS), a compound which damages DNA in regenerating liver in a similar but not identical way to DMN and which does not induce tumors in liver even when given after partial hepatectomy, caused an increase in methylation in relation to synthesis. These experiments therefore do not support the view that altered DNA methylase activity is involved in carcinogenesis.
Chem Biol Interact 1979 Sep
PMID:Effect of a single treatment with the alkylating carcinogens dimethylnitrosamine and methyl methanesulphonate on liver regenerating after partial hepatectomy. IV. Effect on methylase-mediated methylation of DNA. 47 54

Recurrent epistaxis is a common manifestation of patients with a bleeding diathesis. Two patients with epistaxis secondary to a bleeding diathesis managed by local conservative techniques are reviewed. (A case of polycythemia vera and a case of liver failure secondary to hepatoma are reviewed.) Recently bilateral, percutaneous carotid angiography examination was performed on a patient with a bleeding diathesis and intractable epistaxis. At the time of the angiographic examination, embolization of both internal maxillary arteries with Gelfoam particles was accomplished and dramatic control of the epistaxis was achieved. In a patient with severe epistaxis secondary to a bleeding diathesis that is unresponsive to local measures, percutaneous Gelfoam embolization offers substantial advantages over surgical intervention.
Laryngoscope 1979 Sep
PMID:Percutaneous embolization to control intractable epistaxis. 48 Oct 44

Normal rat hepatocytes have been fused with highly differentiated rat hepatoma cells. Some of the hybrids express a physiologically significant level of activity of the urea cycle enzyme ornithine carbamoyltransferase (OCT), a liver-specific function not found in the hepatoma cells. These hybrids have 10% of the adult rat liver OCT specific activity, incorporate 3H-ornithine into protein arginine, and can be selectively grown in arginine-free medium supplemented with ornithine. Somatic cell hybridization of normal differentiated cells with highly differentiated neoplastic cells of the same tissue type may be useful as a general method for obtaining permanent cell lines with new tissue-specific phenotypes.
J Cell Physiol 1979 Sep
PMID:Immortalization of normal liver functions in cell culture: rat hepatocyte-hepatoma cell hybrids expressing ornithine carbamoyltransferase activity. 48 65

The lipid composition of Morris hepatoma 5123c was analyzed together with that of liver and blood plasma from both normal and tumor-bearing rats. The results showed that the liver of tumor-bearing rats contained higher amounts of glycerides, choelsteryl esters, free fatty acids and phospholipids than the liver of normal rats. In the blood plasma of tumor-bearing rats, there was an increase of free cholesterol and triglycerides; this latter difference, however, was not statistically significant. Acyl chain changes in the liver of tumor-bearing rats consisted of an increase of palmitic and oleic acids and a decrease of stearic and arachidonic acids in phosphatidylinositol. Morris hepatoma 5123c contained a lower amount of triglycerides than the livers (both host and normal) and showed a significant decrease of total phospholipids when compared to the host liver. The major acyl chain changes found in Morris hepatoma 5123c compared with both normal and host rat livers were: a) a higher percentage of arachidonic acid together with a lower proportion of palmitic acid in cholesteryl esters; b) an increase of stearic and arachidonic acids and a decrease of palmitic acid in triglycerides; and c) a higher level of palmitic and oleic acids associated with a lower percentage of stearic and C22 polyunsaturated acids in phosphatidylcholine.
Lipids 1979 Sep
PMID:Lipid composition of Morris hepatoma 5123c, and of livers and blood plasma from host and normal rats. 49 62

Variations of endocytic and of lysosomal functions during the cell cycle have been investigated in synchronized hepatoma cells (derived from Morris hepatoma 7288c) by following the cellular uptake of horseradish peroxidase, dextran (mol wt. 70,000), and chloroquine. Cell fractionation and cytochemistry show that in asynchronously growing cells exposed for 1 h to 5 mg/ml peroxidase, the bulk of the enzyme taken up by the cells is found in phagosomes. By using the same experimental system with synchronized HTC cells, large variations of endocytosis are observed during the cell cycle. Peroxidase uptake is lowest during mitosis, increases 5--10 times during G1 phase, reaches a plateau, and finally decreases at the end of S phase and during G2 phase. A similar evolution is observed for the uptake of dextran (0.5 or 1 mg/ml), but it is likely that a significant part of the polysaccharide is still associated with the pericellular surface after 1 h. Moreover, dextran is transferred more slowly than peroxidase to lysosomes. Cellular accumulation of chloroquine is related to intralysosomal pH or to the buffering capacity of lysosomes. Our results show that this drug is taken up more rapidly during G1 and S phases while the rate of accumulation is lowest in mitotic cells. The results are discussed in relation to the modifications of the physical properties of lysosomes during the cell cycle observed previously by cell fractionation and electron microsocopy, and to the possible role of lysosomes in the initiation of mitosis. Cyclic changes of endocytosis in actively dividing cells are demonstrated by our observations and may induce large differences in the uptake rate of extracellular substances.
J Cell Biol 1979 Sep
PMID:Endocytosis and chloroquine accumulation during the cell cycle of hepatoma cells in culture. 51 30

The clonal variation in the rate of albumin production in cultured rat hepatoma cells has been studied on a cellular basis by immunoperoxidase techniques using specific antisera against rat serum albumin. Previously, it has been shown that an array of clonal hepatoma cell populations that produce serum albumin at different rates can be isolated simply by subcloning a single clonal hepatoma cell line (Fu5). The present study demonstrates conclusively that this phenotypic variation is the result of quantal shifts in the rate of albumin production in the individual cells and is not due to changes in the percentage of albumin-producing cells. Also, by analyzing individual colonies as they develop from single cells, it was possible to establish that the rate of variation in albumin content in several hepatoma cell clones is on the order of 0.5-1.4 10(-2) per cell per generation. This variation in albumin content probably reflects shifts in the rate of albumin synthesis. Even after several sequential subclonings, the same clonal variation persists. The variants are not the result of fluctuations in albumin synthesis with different phases of the cell cycle.
Somatic Cell Genet 1979 Sep
PMID:Analysis of discontinuous variation in albumin production by hepatoma cells at the cellular level. 53 34


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