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)

Specific activity and level of polynucleotide phosphorylase (PNPase) in polyribosomes of regenerating liver of adult rats, liver of newborn rats and in malignant tumours of rat (sarcoma M-1 and hepatoma 27) were studied. 24 hours after partial hepatectomy the specific activity and level of PNPase in regenerating liver decreased 3--4 times in the fraction of polyribosomes, bound to the endoplasmic reticulum membranes, and remained at a constantly low level in the fraction of free polyribosomes. The PNPase activity also showed a sharp decrease in the fraction of membrane-bound polyribosomes from newborn rats liver and could not be detected either in free or in bound polyribosomes from sarcoma M-1 or hepatoma 27. The PNPase activity in the fraction of bound polyribosomes increased with a decrease in the rate of liver growth (regenerating liver and newborn rats liver), and reached the level normal for adult animals. Possible mechanisms of regulation of the PNPase activity in animal tissue were studied. It was found that a 2-fold administration of cyclic 3,5'-AMP to intact animals (5 mg per 100 g of body weight) with an interval of 8 hours, corresponding to the interval between two peaks of the increase in cyclic 3,5'-AMP concentration following partial hepatectomy, diminished the PNPase specific activity in polyribosomes by 30%. A factor, presumably of protein origin, which induced a release of PNPase from polyribosomes of normal rat liver but did not affect the activity of the liberated enzyme, was detected in the cell sap of sarcoma M-1 and hepatoma 27.
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PMID:[The activity of polynucleotide phosphorylase in polyribosomes of regenerating liver of adult rats, liver of newborn rats and in some reinoculated tumours]. 19 Nov 6

The standard lead precipitation method was used for ultracytochemical localization of glucose-6-phosphatase (G-6-Pase) in the in vivo and in vitro forms of the Chang rat hepatoma and in the normal adult rat liver. Reaction product was visualized as very fine particulate within the cisternae of the nuclear envelope and endoplasmic reticulum. Cytochemically, the amount of the G-6-Pase reaction product in both forms of the tumor cells was obviously less than that in the normal hepatocytes. Apparently, the enzyme was not completely deleted from the hepatoma cells. The results supported some biochemical data of certain other hepatomas. The successful ultracytochemical localization of G-6-Pase in cultured hepatoma cells has not been reported previously.
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PMID:Ultracytochemical localization of glucose-6-phosphatase in Chang rat hepatoma in vivo and in vitro. 19 99

A case of hepatoma in a 79-year old woman is reported. The patient had an enlarged liver and a pathological liver scintigram. Percutaneous liver biopsies were performed both with Menghini-and fine needles. The most prominent feature was the presence of hyaline cytoplasmic PAS-negative inclusions in liver parenchymal cells. There was no nuclear atypia. Electron microscopy disclosed two types of cytoplasmic changes. One consisted of a lamellar ultrastructure and was interpreted as a hyperplasia of smooth-surfaced endoplasmic reticulum. The other change consisted of smooth globular non-membrane limited regions containing amorphous or finely fibrillar material. This was interpreted as corresponding to the hyaline inclusions visible in the light microscope. The presence of PAS-negative hyaline cytoplasmic inclusions may thus be a sign of hepatoma. This may be of relevance for the diagnostic considerations of material obtained by fine needle biopsy.
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PMID:Hyaline cytoplasmic inclusions in human hepatoma. A case report. 19 65

Some characteristics of the mitochondria of hepatocytes and of three hepatoma cell lines have been compared. By means of stereologic analysis of electron micrographs of cross-sections through cells the volume of mitochondria per unit volume of cell cytoplasm and the surface areas of the mitochondrial envelope and cristae membranes have been measured. The relative mitochondrial volume in the cytoplasm decreases with increasing growth rate but the surface area of outer and cristae membranes per unit volume of mitochondria is not altered. The internal organization of hepatoma mitochondria, however, differs distinctly from that of normal liver mitochondria as evident from electron micrographs; the hepatoma cells contain mitochondria in which parallel cristae appear to cross the whole mitochondrial profile unlike the irregular, short cristae seen in normal liver mitochondria. Furthermore, in the fast-growing hepatoma cells the mitochondrial matrix appears less dense than in the hepatocyte. Hepatoma cells contain less organized rough endoplasmic reticulum than normal liver cells and the spatial relationship of the mitochondria to the rough cisternae, seen in the hepatocyte, is absent in the fast-growing hepatoma cell lines. It is concluded that hepatoma cells have fewer mitochondria than normal liver cells, but that the organelles have a normal content of inner membranes.
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PMID:A morphologic and morphometric study of the mitochondria in several hepatoma cell lines and in isolated hepatocytes. 20 39

The subcellular and submitochondrial localization of CTP:phosphatidate cytidylyltransferase is altered in the Morris 7777 hepatoma. Mitochondria in this poorly differentiated tumor are the principal sites of CDP-diacylglycerol synthesis, in contrast to normal rat liver where the endoplasmic reticulum is most active. This enzyme activity was increased 17-fold in the outer mitochondrial membrane, and a 22% increase was noted in the inner mitochondrial membrane of the 7777 hepatoma as compared with the corresponding fractions from normal rat liver. Increased mitochondrial CTP:phosphatidate cytidylyltransferase was present in six other Morris hepatomas, but it was not found in fetal rat liver mitochondria, suggesting that rapid growth alone is not responsible for the difference. Evidence is presented which indicates that mitochondrial lipid degradation is similar in normal liver and the 7777 hepatoma, in vitro. The increased activity of CTP: phosphatidate cytidylytransferase is thought to be responsible in part for the moderately increased diphosphatidylglycerol content of 7777 hepatoma mitochondria.
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PMID:Altered subcellular and submitochondrial localization of CTP:phosphatidate cytidylyltransferase in the Morris 7777 hepatoma. 20 10

An electronmicroscopic study of STH cells from mice bearing transplanted hepatomas was performed at different time points, in a circadian period. Normal mice served as controls. The STH cells of control animals showed circadian variations inplasmic reticulum and lysosomes, which suggest increased secretion of growth hormone along the light peroid. In mice bearing hepatomas the morphologic aspect of these organelles would also indicate an increase of STH elaboration at 1200 and 1600. These changes were more remarkable than in controls and mainly consisted of hypertrophy of the Golgi complex, extended and compact endoplasmic reticulum and presence of large amounts of lysosomes. Besides, another peak of secretion seems to be present at 0000, considering the dilatation of the Golgi complex and endoplasmic reticulum cisternae. Some findings are coincident with observations made by others in the hypophysis of animals bearing transplantable tumors, where circadian periodicity was not studied. The STH cytological circadian variations could be correlated with other variations could be correlated with other variables, such as STH values in plasma and hypophysis, and DNA synthesis and mitotic activity of SS1-H hepatoma.
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PMID:Ultrastructure of somatotroph cells at different times in a circadian period, in mice bearing a slow growing transplanted hepatoma. 20 51

Line 10 guinea pigs hepatoma cells are resistant to killing by antibody and guinea pig complement. Metabolic inhibitors (adriamycin and actinomycin D) that increase the sensitivity of the cells to antibody-complement (C) killing were examined for their effects on the ability of the cells to synthesize and incorporate specific lipids into plasma membrane and intracellular membrane fractions. Drug-treated cells that had been rendered sensitive to antibody-C killing were inhibited in their incorporation of newly synthesized phosphatidylcholine and cholesteryl ester into the plasma membrane, as well as incorporation of phosphatidylcholine, cardiolipin, cholesteryl ester, and triglyceride into certain intracellular organelles including mitochondria, endoplasmic reticulum, nuclear membrane, or microsomes. Drug-treated cells recultured in the absence of the drug regained their ability to resist antibody-C killing and to synthesize and incorporate lipids into plasma and intracellular membranes. These data suggested that agents modifying the sensitivity of the tumor cells to humoral immune killing have a concomitant effect on plasma membrane and intracellular lipid synthesis.
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PMID:Plasma membrane and intracellular lipid synthesis in tumor cells rendered sensitive to humoral immune killing after treatment with metabolic inhibitors. 29 16

Line 10 guinea pig hepatoma cells are resistant to killing by antibody plus guinea pig complement but not by antibody plus human complement. Agents that increase (metabolic inhibitors) or decrease (hormones) the sensitivity of the cells to killing by antibody plus complement were examined for their effects on the chemical, physical, and enzymic composition of the cells. The effects of these agents on the chemical and enzymic characteristics of isolated plasma membrane and intracellular fractions of these cells were also measured. Adriamycin treatment resulted in a decrease in the amount of ribonucleoprotein and smooth endoplasmic reticulum isolated from the cells as compared to untreated cells. Hormone (insulin or hydrocortisone)-treated cells were enhanced in their yield of this fraction but were decreased in their yield of mitochondria as compared to controls. Generally, the drug-treated cells were decreased, whereas hormone-treated cells were enhanced, in protein, lipid phosphate, and total phosphate content, as compared to untreated controls. This pattern was also noted in the plasma membrane fraction of the cells and, in several cases, in intracellular membrane fractions. These data suggest that the protein, lipid phosphate, and total phosphate content of the plasma membrane and intracellular membranes of these cells may correlate with their ability to resist humoral immune attack.
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PMID:Physical and chemical composition of subcellular fractions from tumor cells treated with metabolic inhibitors or hormones. 42 Dec 20

Novikoff kepatoma microsomes catalyze the hydroxylation of benzphetamine and ethylmorphine at rates less than 1% of those of liver microsomes but catalyze the hydroxylation of p-nitroanisole and p-nitrophenetole at rates about 40% of those of liver microsomes. Benzo[a]pyrene hydroxylation is also catalyzed by Novikoff hepatoma microsomes at about 2% of the rate of liver microsomes. Like the hepatic microsomal system the rates of substrate hydroxylation by Novikoff hepatoma microsomes can be increased by pretreatment with phenobarbital/hydrocortisone or beta-naphthoflavone and inhibited by carbon monoxide, SKF-525A, and 7,8-benzoflavone. In addition, NADPH-cytochrome P-450 reductase (NADPH:ferricytochrome oxidoreductase, EC 1.6.2.4) has been partially purified from Novikoff hepatoma ascites cells and some properties are described. The induction and inhibition characteristics of the Novikoff hepatoma microsomal hydroxylation activities and the isolation of a cytochrome P-450 reductase from the hepatoma are consistent with the presence of a functional mixed function oxidase system in the Novikoff hepatoma, analogous to that present in liver endoplasmic reticulum.
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PMID:Drug metabolism in the Novikoff hepatoma: evidence for a mixed function oxidase system and partial purification of cytochrome P-450 reductase. 71 41

Livers of 6- to 7-week-old male C3H/He, CBA, A, and BALB/c mice were examined by electron microscopy for the presence of intracisternal A particles (ICAP) after administration of diethylnitrosamine (DEN) in drinking water. In control mice, ICAP were extremely rare; they were found in the livers of only 2 mice (strains C3H/He and A; none in the other strains). By contrast, the treatment of mice with DEN greatly enhanced the appearance of ICAP in the liver cells of all strains. Within 2 weeks of the treatment, ICAP were found in 8-26% of liver cells examined in all mice and the number of ICAP/cell ranged from 3 to 12. Aside from mild disorganization of the rough endoplasmic reticulum, such as segmentation and vesiculation, liver cells of carcinogen-treated mice showed none of the consistent abnormalities that characterize the appearance of ICAP. The reactivation of ICAP (which are usually suppressed in adult mice) by DEN may become a useful marker for analysis of the sequential alterations of the liver that lead to the development of hepatoma during carcinogenesis.
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PMID:Activation of intracisternal A particles in mouse liver by diethylnitrosamine. 84 86


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