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)

In the hepatoma cells, AFP synthesis was found to occur through ribosomes of the rough endoplasmic reticulum, since AFP was demonstrated around ribosomes of the rough endoplasmic reticulum by the peroxidase antibody technique. The secretory process was suggested to be as follows: smooth endoplasmic reticulum takes a part and the Golgi apparatus does not. Concerning the early transitory appearance of AFP in the course of hepatocarcinogenesis by 3'Me-DAB, AFP might be produced by proliferated ampulla cells, which exist between the cholangioles and liver cell cords.
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PMID:Immunoelectronmicroscopic study of alpha-fetoprotein synthesis in hepatoma cells. 5 22

The presence of hepatitis B virus (HBV) antigens was examined in specimens of liver tissue obtained at necropsy from black Senegalese patients suffering from primary hepatocellular carcinoma (PHC). The results were correlated with markers of hepatitis B infection in serum. Hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) were sought for in 15 liver extracts. HBsAg was found in the liver in 10 of 12 cases with HBsAg-positive serum. HBcAg was detected in three livers. The HBsAg was detected in seven of eight livers by immunofluorescence and orcein staining. HBsAg-positive cells were mainly located in the peri-tumoral cirrhotic tissue, although positive hepatocytes were also found in tumour nodules in liver from one of the patients. HBcAg was found in five of seven cases by immunofluorescence in hepatocytes of the cirrhotic areas. HBcAg fluorescence was primarily nuclear but, in some lobules, a patchy cytoplasmic fluorescence was observed. This suggests a cytoplasm-nucleus pathway in the synthesis of the HBV core antigen. Electron microscopy was performed on two HBsAg- and HBcAg-positive cases. Fibrillar and crystalline cytoplasmic inclusions were observed in tumour cells. In the same cells, 20-25 nm virus-like particles were present in swollen cisternae of the endoplasmic reticulum.
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PMID:Hepatitis B virus antigens in human primary hepatocellular carcinoma tissues. 9 79

Differences in the binding sites for polyribosomes, template-depleted ribosomes and large ribosomal subunits were found in microsomal derivatives of the rough endoplasmic reticulum. 1. The stoicheiometry of polyribosome and ribosome interaction in vitro with membranes was shown to be influenced by the relative concentration of interactants and the duration of their mixing. Large ribosomal subunits required a more prolonged mixing schedule to achieve saturation of membranes than did polyribosomes. 2. By using a procedure which minimized the effects on binidng by the stoicheiometric variables, competition between populations of polyribosomes, ribosomes and subunits for membrane sites showed that subunits, and to a lesser extent ribosomes, failed to block polyribosome attachment. 3. Polyribosomes isolated from liver, kidney and hepatoma 5123C entirely bound to a common membrane site, but some polyribosomes from myeloma MOPC-21 bound to other sites, perhaps influenced by their unique nascent proteins. 4. Subunit-binding sites appear on rough membranes only after endogenous polyribosomes have been removed, but no evidence that resulting changes in surface constituents are responsible was found. Large-subunit binding was largely abolished by lowering MgC12 concentration of 0.1 mM, whereas under the same conditions polyribosome binding was undiminished. 5. The large-subunit site appears to be distinct from the polyribosome site not only in the restriction of its affinity for particles but also spatially, to the extent that bound subunits do not hinder access of polyribosomes to their sites.
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PMID:The selectivity and stoicheiometry of membrane binding sites for polyribosomes, ribosomes and ribosomal subunits in vitro. 16 19

Albumin molecules appeared to be synthesized in the light hepatocytes of rats by bound polysomers on rough and endoplasmic reticulum and the nuclear envelope. The molecules were discharged directly into the cytosol, then to the external cellular spaces. This conclusion failed to support the current theory from biochemical studies that albumin is synthesized by bound ribosomes, discharged into the cisternae of rough endoplasmic reticulum, and transported to the smooth endoplasmic reticulum and then to the Golgi apparatus. In addition to the liver, positive syntheic activities were observed in the aorta, kidney, and hepatoma cells of rat. Earlier investigators have reported that only liver cells can synthesize albumin.
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PMID:Electron microscopy of albumin synthesis. 17 Jun 82

The effects of AC-3579 (NSC-170561), a new experimental antitumour drug which depresses phospholipid catabolism in liver, were compared in rat aflatoxin-induced hepatoma and in non-neoplastic hepatocytes surrounding the tumour. Ultrastructural lesions, characterized by the hypertrophy of the smooth endoplasmic reticulum and the presence of lamellate cytosomes appeared in both tissues. They were less marked in hepatoma than in non-neoplastic cells. As in control livers, they were related to an invrease in pohspholipid concentration due to the decrease of phospholipid breakdown. In addition, chemical analysis demonstrated differences between hepatoma, non-neoplastic aflatoxin-treated liver and control liver: total and free cholesterol were decreased, relative concentration of sphingomyelin increased and that of phosphatidylethanolamine decreased by about 50%, in both hepatoma and non-neoplastic liver. Phospholipid concentration was decreased by 50% in tumour cells. After AC-3579 treatment total cholesterol was increased 3.2 fold in non-neoplastic liver and 2.5 fold in hepatoma but not in control liver.
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PMID:Effects of the diazafluoranthen derivative AC-3579 (NSC-170561), a new experimental antitumour drug, on rat hepatoma. 17 50

Smooth and rough endoplasmic reticulum from rat liver and hepatomas exhibited endogenous protein kinase activity independent of adenosine 3':5'-monophosphate. The phosphorylation of smooth membranes by this process was consistently higher than that of rough membranes. When histone was added along with the smooth endoplasmic reticulum, cyclic AMP stimulated protein phosphorylation. Analysis of membrane-phosphorylated proteins by gel electrophoresis showed 5 major phosphorylated bands with estimated molecular weights of 155 000, 62 000, 50 000, 46 000 and 43 000, whereas major bands having estimated molecular weights of 62 000, 50 000 and 43 000 were found in membranes of the smooth endoplasmic reticulum of the Morris hepatoma 5123 C. Since previous studies in this and other laboratories have demonstrated the similarity of the protein components of membranes of the endoplasmic reticulum of normal liver and hepatoma, our findings indicate an inability of the protein kinase of hepatoma intracellular membranes to phosphorylate protein species that are found in membranes of both liver and the neoplasm.
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PMID:Protein phosphorylation of the smooth and rough endoplasmic reticulum in normal and neoplastic liver of the rat. 18 Dec 47

Mitonchondria isolated from the Morris hepatoma 7777 demonstrated a markedly different phospholipid composition from those of control mitochondria, both with respect to the amounts of the various types present and the fatty acid composition. The level of polyunsaturated fatty acids in the mitochondrial phospholipids was lowered, wheras there was an increase in the level of monounsaturated fatty acids. Moreover, the usual distribution of saturated fatty acids at position 1 and polyunsaturated fatty acids at position 2 does not exist in hepatoma phospholipids; a high percentage of monounsaturated fatty acids was found at both positions. The cardiolipin content was lower in hepatoma mitochondria (3.7%) than in livers of animals with hepatomas (5.2%). There was, however, some compensation in the amount of acidic phospholipids in these mitochondria due to an increase in phosphatidylserine (4.9% versus 1.3%). The force-area curves of the hepatoma phospholipids spread on a monomolecular film demonstrated a smaller area per molecule than those from liver mitochondria. The zeta potential of liposomes of the hepatoma phospholipids (-45) was less than those of control mitochondria (-81), as determined by microelectrophoresis. The calcium-stimulated phospholipase A activity of the hepatoma mitochondria appeared to be more readily expressed than the same activity in liver organelles. The maximal activity was lower, however, than that noted in liver mitochondria. Furthermore, by following the incorporation of [3H]ethanolamine into mitochondria phospholipids, it was established that the conversion of glycerophosphorylethanolamine to glycerophosphorylcholine was increased in the hepatoma. These observations suggest dramatic changes in phospholipid metabolism in the hepatoma, at the level of both the endoplasmic reticulum and the mitochondrion. Accompanying the changes in phospholipid compositon and metabolism were alterations in mitochondrial energy-linked processes. The hepatoma mitochondria demonstrated lower respiratory control ratios even when isolated in an isotonic solution containing 1mM ethylenediaminetetraacetate and bovine serum albumin (0.5 mg/ml). This was due to increased state 4 respiration.
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PMID:Alteration of mitochondrial function and lipid composition in Morris 7777 hepatoma. 18 46

The morphology and occurrence of tubuloreticular and undulating membraneous structures (TRS and UMS) associated with the endoplasmic reticulum were examined under normal and pathologic conditions. It was concluded that TRS and UMS are cytoplasmic inclusions of similar type but of different organization. The occurrence of UMS in a human cell line derived from a carcinoma of the lung and in a transplantable chicken hepatoma derived from an MC-29 virus-induced liver tumour is described.
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PMID:Undulating membraneous structures associated with the endoplasmic reticulum in tumour cells. 18 16

We examined whether hormones would modify the carcinogenic action of aflatoxin B1 (AFB1). Four groups of inbred Fischer rats received AFB1, 125 mug per animal, weekly per os. In three of the groups, certain hormones were administered simultaneously: One group received 1 U growth hormone (GH) sc weekly, another was given 4 U adrenocorticotropin (ACTH) weekly, and a third received 0.5 U insulin weekly sc. AFB1, ACTH, and insulin were given for 20 weeks; GH was given for only 10 weeks. The control group did not receive hormone adjuvant. In each group, 4 animals were killed at 7, 14, 21, 28, and 35 weeks; the remaining rats were killed at 77 weeks. Their livers were carefully examined and samples prepared for light and electron microscopy. Animals receiving AFB1 and ACTH failed to exhibit hepatocellular carcinoma. On the other hand, malignant lymphoma appeared at 56 weeks in 3 of the 6 surviving males on this regime. AFB1, alone or when given with insulin or GH, caused hepatocellular carcinoma in all animals; in these, lymphoma was not observed. Lymphoma comprised two cell types, each with similar neclear characteristics but differing in their nucleocytoplasmic ratios and in the amount and distribution of cytoplasmic organelles. Alterations leading to hepatocellular carcinoma were examined at various stages of development. "Basophilic hyperplasia" reflected an increase in free ribosomes. "Hyperplastic nodules" were composed of hepatocyte aggregates with characteristics similar to those encountered in the earlier stage. Both the "neoplastic nodules" and hepatocellular carcinomas were formed by cells containing large, "smooth fingerprints" and free ribosomal aggregates. These features supported the concept that AFB1 impairs ribosomal binding to endoplasmic reticulum membranes. The failure of ACTH-treated animals to develop hepatocellular carcinoma was ascribed to the effect of adrenal cortical stimulation upon membrane-polysome binding.
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PMID:Inhibition of hepatocarcinogenesis by adrenocorticotropin in aflatoxin B1-treated rats. 18 49

Mallory bodies (MBs) were isolated from the livers of 8 alcoholic patients and a malignant hepatoma occurring in a non-alcoholic patient. MBs were isolated in large quantity and high purity. The isolates were devoid of liver cell organelles except in the case of malignant hepatoma where dense and membranous material resembling nuclear substances and endoplasmic reticulum were found. The "nuclear" material had continuity with MBs. Electron microscopic examination suggested the presence of a dense body and very fine filaments within in situ and isolated MBs in addition to the tubular structure of so-called MB fibers. Amino acid analysis indicated that the major component of MBs is a protein which does not contain unusual amino acids or any particular amino acid in a large quantity to characterize this protein. The isolated fractions were solubilized in 6 M guaindine hydrochloride by sonication or in 1% sodium dodecyl sulfate (SDS) with 2 mercaptoethanol and 8 M urea. The solubilized MB protein produced 3 peaks by Sephadex G 100 chromatography and at least five intense protein bands by SDS polyacrylamide gel electrophoresis. Serum sample and the fractions from control livers contained several protein bands which were similar to the major components of isolated MB protein. These morphological and biochemical findings suggest that MBs are not homogeneous protein, but they are probably complexes of various proteins and that some components of MBs are present in normal hepatocytes.
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PMID:A study on Mallory bodies. Isolation, ultrastructure and preliminary biochemical characterization of Mallory bodies from livers of alcoholic cirrhosis and malignant hepatoma. 18 65


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