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 order to evaluate geographical differences in the liver pathology of ducks infected with duck hepatitis B virus (DHBV), ducks in Chiba and Shimane, Japan, and Shanghai, China, were investigated. The numbers (DHBV positive/negative) and the maximum age of the ducks examined were 18/10 at 19 mo, 15/1 at 3 yr 4 mo, and 72/27 at 18 mo, respectively. DHBV infection was induced experimentally in ducks from Chiba and Shimane but was present congenitally in those from Shanghai. Ducks were examined regarding liver function tests, conventional histology, immunohistology, electron microscopy, and molecular hybridization for DHBV DNA in the serum and liver. There was no significant difference between DHBV-positive and -negative ducks in bilirubin and transaminase and alkaline phosphatase activities in the sera. Histologically, while the livers of ducks from Chiba and Shimane did not show necroinflammatory (hepatitis) activity, those from Shanghai frequently did (52.5%). Necroinflammatory activity of the Shanghai ducks was present almost equally in both DHBV-positive and -negative livers. The livers of Shanghai ducks but not the other two areas often (8.3%) had ground-glass inclusions which corresponded ultrastructurally to numerous virus particles in the dilated cisternae of the proliferated endoplasmic reticulum. No advanced liver disease, such as cirrhosis or hepatocellular carcinoma, was observed. There was no significant difference in the amount of DHBV DNA in the sera or in its pattern in the liver tissue among ducks of the three areas. In addition, the livers of Chiba ducks frequently had amyloidosis, while those of Shanghai ducks were contaminated with parasites. In conclusion, DHBV infection did not appear to provoke significant hepatitis activity or advanced liver disease in the examined ducks of all three areas, and the DHBV-positive livers from Shanghai ducks showed a different morphological appearance from those of the other two areas. This variation might reflect the difference in the strain of ducks, subtypes of DHBV, environmental factors, or a combination of these influences.
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PMID:Geographical pathology of duck livers infected with duck hepatitis B virus from Chiba and Shimane in Japan and Shanghai in China. 334 10

The effect of carcinogenesis on various hepatic microsomal parameters and related cell functions was studied in two tumor models. Hepatocarcinoma was produced by diethylnitrosamine (DEN) and 2-acetylaminofluorene (2-AAF) (Solt-Farber model) and mammary adenocarcinoma using R3230 AC cancer cell line. In these models the effect of the tumor on metabolic functions of hepatocytes was studied. In the DEN/2AAF tumor model in nodules phase I components (cytochrome P-450, aminopyrine N-demethylase, arylhydrocarbon hydroxylase) were reduced, together with microsomal progesterone content and total and specific progesterone binding. Phase II components (glutathione, glutathione S-acyltransferase, UDP-glucuronyl transferase, epoxide hydrolase) were increased. In hepatoma the effects were more enhanced. Nodules grown in the speen retained the dedifferentiated enzyme characteristics. In the R3230 AC mammary adenocarcinoma phase I components of the hepatic endoplasmic reticulum were reduced, and phase II components increased. Progesterone content and receptor binding were also increased. These results indicate that enzymatic abnormalities in the liver cell are connected with cancer production and the hepatic dedifferentiation seems to be indistinguishable in tumor-bearing liver from those seen with extrahepatic neoplasms.
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PMID:Hepatic metabolism and carcinogenesis. Its role in hepatoma and adenocarcinoma. 338 80

Rough and smooth endoplasmic reticulum (ER) membranes and trans-Golgi apparatus (GA) fraction, intermediate GA fraction, and cis-GA fraction from White Leghorn chicken liver and hepatoma Mc-29 were isolated. Their purity was checked by electron microscopy and by determination of the activity of the marker enzymes. Rough and smooth membranes were also identified by calculation of the ratio between the content of RNA and the total phospholipids. It was found that the membrane fractions were pure enough. The tumor exhibited a decreased amount of ER and a small GA when compared when the ER and GA in the liver. The biogenesis of membrane glycoconjugates was followed by in vivo experiments either with [14C]glucosamine or by double labeling with [14C]N-acetylmannosamine and [3H]leucine. The radioisotope studies indicated that the synthesis rate of protein in liver and hepatoma rough ER was nearly the same, but in the tumor cells the glycosylation of the nascent polypeptide chain and the formation of glycolipids were significantly decreased.
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PMID:Isolation and characterization of chicken liver and hepatoma Mc-29 endoplasmic reticulum and Golgi apparatus membranes and biosynthesis of their glycoconjugates. 347 May 44

Surgical specimens of 175 cases of primary hepatocellular carcinoma were prepared by routine paraffin section and HE stain. The clear cell cancer specimens were stained with PAS. All the specimens were observed by light microscope. Ultrathin sections were made for 50 samples and studied by electron microscope. Under the light microscope, 79 (45.1%) showed varying amounts of clear cells. According to the proportion and distribution of these cells, clear cell carcinoma of the liver was divided into three types: scattered type (16 cases, 20.3%), localized (43, 54.4%) and diffuse types (20, 25.3%). The clear cancer cells could be found in hepatoma with various degrees of differentiation. Of these 79 cases, 4 (5.1%) were grade I, 53 (67%) and 22 (27.9%) were grades II and III. Positive PAS stain gives an evidence of glycogen in the clear cell cytoplasm. 7 diffuse type clear cell hepatomas were observed with electron microscope. The cytoplasm had only fewer organelles, leading to a void appearance. The amount of the rough endoplasmic reticulum, free ribosome and polyribosome was markedly decreased. So was mitochondria, usually showing swelling and abnormality. The residual rough endoplasmic reticulum and mitochondria were out of normal arrangement. They often aggregated on one side of the nucleus or near the cell membrane. Glycogen particles were increased in some cell cytoplasms. Some particles were even and fine, some were aggregated into masses or scattered. Nuclei showed abnormalities mild to moderate. The nature of the clear cells in liver cancer is the variance of glycogen or lipid in the cytoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Ultrastructure of primary clear cell carcinoma of the liver]. 358 12

Subcellular fractions of nuclei, mitochondria, endoplasmic reticulum, plasma membrane and cytosol were prepared from liver and hepatoma 7288CTC. Marker enzyme activities, biochemical compositions and electron microscopy were used to establish purity. Hepatoma NADH: cytochrome C reductase and 5'-nucleotidase exhibited abnormal subcellular distributions. The lipids from the subcellular fractions were examined in detail. Mitochondria and plasma membranes were characterized by elevated percentages of diphosphatidylglycerol and sphingomyelin, respectively, in both tissues. All hepatoma subcellular fractions contained dramatically elevated levels of sphingomyelin and cholesterol, two components that form preferential strong complexes in vitro. The fatty acid composition of hepatoma sphingomyelin differed markedly from liver and, unlike liver, did not exhibit organelle specific compositions. Some hepatoma lipid classes contained reduced percentages of palmitate while others contained higher levels. Hepatoma phosphatidylcholine and phosphatidylethanolamine from organelles contained lower percentages of long chain polyunsaturated fatty acids than liver. Generally, unique fatty acid profiles exhibited by individual phospholipid classes of liver subcellular fractions were absent or much reduced in the hepatoma. The ratios of oleate to vaccenate were near one for most of the phospholipid classes of most liver fractions, but all hepatoma classes, with few exceptions, contained a much higher percentage of oleate in all subcellular fractions. The hypothesis is proposed that the origin of some acyl moieties for the biosynthesis of various hepatoma lipid classes differs from liver sources. The possible changes in acyl pools, sources and compartments for complex lipid biosynthesis could result in change in the quantities of molecular species that could contribute to the abnormal properties of the hepatoma membranes.
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PMID:A comparison of lipids from liver and hepatoma subcellular membranes. 371 48

We investigated the biosynthesis of the human insulin receptor in IM-9 lymphocytes and HEP-G2 hepatoma cells. Cells were first pulse labeled for 15 min with [35S]methionine and then chased for up to 4 h. At each time, the cells were solubilized in 1% Triton X-100; the insulin receptor was immunoprecipitated and then analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (6%) and fluorography. At 15 min, a major precursor protein of 190,000 Mr was precipitated. During the chase period, two smaller proteins became apparent, which evolved into two major species of 130,000 and 95,000 Mr, the mature alpha- and beta-subunits, respectively. When IM-9 cells were trypsinized after pulse chase, the alpha- and beta-subunits were completely digested, whereas the 190,000-Mr precursor was unaffected. 125I-surface labeling of cells, followed by immunoprecipitation, revealed the presence of only the alpha- and beta-subunits, indicating that only these two species were on the cell surface. To study this biosynthetic pathway, several inhibitors were used (tunicamycin, monensin, and swainsonine). These inhibitors revealed the following. The receptor is first synthesized as a 170,000-Mr protein that is cotranslationally N-glycosylated to yield a high-mannose 190,000-Mr precursor. This precursor is rapidly transported from the endoplasmic reticulum to the Golgi apparatus where it is cleaved into two subunits of 120,000 Mr (alpha) and 90,000 Mr (beta). These subunits then increase in molecular weight by processing of the high-mannose oligosaccharides to the low-mannose complex type. The two subunits then migrate to the cell surface where they function to transmit the insulin signal.
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PMID:Biosynthesis and processing of the human insulin receptor. 372 Oct 67

Four hybrid clones obtained by fusion of mouse hepatoma cells with mink fibroblasts treated with polyethyleneglycol were studied morphologically and morphometrically using electron microscopy. The clones studied contained a double set of mouse chromosomes and different numbers of mink chromosomes. It is demonstrated that clones containing different mink chromosomes differ considerably from each other and from the parental cells in the manifestation of some morphological characters (form and type of cell growth, form of the nucleus, structure of mitochondria, distribution of membranes of the granular endoplasmic reticulum), as well as in some quantitative parametres of organelles (area of the cut of the cell and of the nucleus, a relative volume of the nucleus). The data obtained witness for the fact that some morphological traits characteristic of cells of a certain parental type may appear in hybrids independently of each other, and that the degree of their manifestation may depend on the number of chromosomes of one of the parents or, possibly, on one particular chromosome.
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PMID:[Characteristics of the submicroscopic structure of hybrid clone cells obtained by the fusion of mouse hepatoma cells and mink fibroblasts and containing different numbers of mink chromosomes]. 375 Apr 10

The processing and secretion of newly synthesized hepatic lipase was characterized in FU5AH rat hepatoma cells. Pulse-chase experiments revealed two immunoreactive species with apparent molecular weights of 55,400 and 57,600. The 55.4 kDa species was detectable only in cell extracts, whereas the 57.6 kDa species was present in both cell extracts and media. Following a 5 min pulse with L-[35S]methionine and a 10 min chase, these two species represented only 0.003% of the total labelled protein. Quantitation of the 55.4 kDa and 57.6 kDa species in a chase time course taken together with their respective sensitivity and resistance to digestion with endo-beta-N-acetylglucosaminidase H indicates that the 55.4 kDa species is a high mannose precursor to the mature 57.6 kDa enzyme which contains only complex N-linked oligosaccharides. From a time course of endo-beta-N-acetylglucosaminidase H digestion, it was determined that hepatic lipase contains a minimum of two N-linked oligosaccharides. Treatment of the 55.4 kDa species with endo-beta-N-acetylglucosaminidase H yields a protein with a kDa value similar to that observed after treatment of the mature secreted enzyme with endo-beta-N-acetylglucosaminidase F or trifluoromethanesulfonic acid. Therefore, processing of N-linked oligosaccharides is probably the only post-translational modification responsible for the observed change in the apparent molecular weight of hepatic lipase. The half-residence times of hepatic lipase in the endoplasmic reticulum-cis Golgi region and in the cell were estimated at 34 min and 57 min, respectively. Newly synthesized hepatic lipase in Fu5AH cells is secreted constitutively and is not stored in an intracellular pool. Finally, little of the newly synthesized enzyme is degraded during the course of a 1 h chase.
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PMID:Characterization of the intracellular processing and secretion of hepatic lipase in FU5AH rat hepatoma cells. 381 25

A soluble lectin, the core-specific lectin (CSL), is synthesized and secreted by rat hepatocytes and the rat hepatoma cell line, H-4-II-E. This lectin binds mannose and N-acetylglucosamine residues in the "core" region of Asn-linked oligosaccharides. Secretion of the CSL was found to occur over an extended period of time, greater than 4 h being required for secretion of 50% of the lectin (Brownell, M. D., Colley, K. J., and Baenziger, J. U. (1984) J. Biol. Chem. 259, 3925-3932). We have determined that following synthesis in the endoplasmic reticulum, the CSL is rapidly transported to the Golgi where it is retained for an extended period of time prior to secretion. The lectin undergoes two post-translational modifications within the Golgi: an increase from Mr 24,000 to 25,000 and a progressive decrease in pI with an accompanying increase in Mr to a final value of 26,000. The lectin is also assembled into high molecular weight complexes of 150-260 X 10(3) and acquires the ability to bind carbohydrate in the Golgi. In hepatoma cells, the 24,000-25,000 modification is completed 20 min after initiation of synthesis. Assembly of the CSL subunits into high molecular weight complexes, acquisition of carbohydrate binding activity, and the 25,000-26,000 modification occur between 20 and 80 min after initiation of synthesis. These events have slower kinetics in primary hepatocytes and this allowed us to determine that the sequence of these biosynthetic events is: the 24,000-25,000 modification, complex assembly, the 25,000-26,000 modification, and acquisition of carbohydrate binding activity. The 24,000-25,000 modification occurs prior to complex assembly. Complex assembly may occur prior to, or concomitant with, the 25,000-26,000 modification. Assembly into the oligomeric form and the 25,000-26,000 modification correlate with the attainment of carbohydrate binding activity. The kinetics of CSL modification and assembly cannot account for its retention within the Golgi. Interaction with Golgi components either through carbohydrate binding or another interaction, may act to selectively retain the lectin within the Golgi.
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PMID:Biosynthesis and secretion of the rat core-specific lectin. Relationship of post-translational modification and assembly to attainment of carbohydrate binding activity. 381 49

The synthesis, transport and processing of cathepsin C was studied in Morris hepatoma 7777 cells by metabolic labelling, immunoprecipitation and characterization of labelled polypeptides by gel electrophoresis and fluorography. The largest detectable precursor of cathepsin C was a polypeptide of Mr = 92 500. Even 3 min after synthesis this precursor was accompanied by four polypeptides with Mr values ranging from 63 000 to 54 000, indicating cleavage of the precursors within the endoplasmic reticulum. The early forms of cathepsin C were associated with low-buoyant-density organelles containing the markers of endoplasmic reticulum and Golgi complex. About 30% of these early forms were secreted within 3 h after synthesis. The remaining 70% were transferred into dense lysosomes and processed between 2 and 3 h after synthesis to a mixture of the least five major and nine minor polypeptides with Mr values ranging from 73 000 to 12 000. These forms remained stable for at least 3 days. In freshly isolated hepatocytes cathepsin C was processed to forms closely related to those found in the hepatoma cells. Cathepsin C was synthesized in Morris hepatoma 7777 cells as a glycoprotein with mannose-6-phosphate residues that mediated mannose-6-phosphate-specific receptor-dependent uptake in human skin fibroblasts. In contrast to hepatocytes, synthesis of mannose-6-phosphate receptors in Morris hepatoma 7777 cells was below the limit of detection. The hepatoma cells did not express at the cell surface these or other receptors mediating endocytosis of lysosomal enzymes. Further, processing and transport of newly synthesized cathepsin C was largely resistant to NH4Cl. Apparently, cathepsin C is transferred in Morris hepatoma 7777 cells by a mechanism independent of mannose-6-phosphate-specific receptors.
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PMID:Synthesis, transport and processing of cathepsin C in Morris hepatoma 7777 cells and rat hepatocytes. 406 48


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