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

5 human cases of hepatoma have been chosen with respect to their different seric alpha-fetoprotein (alpha-FP) level and histological characters. Cells producing alpha-FP have been studied with specific horseradish-peroxidase-labelled immunoglobulins. Ultrastructural examination shows that alpha-FP is present in the cytoplasm of some tumoral hepatocytes. alpha-FP is also present in the cytoplasm of some rare nontumoral hepatocytes of a nonsecreting hepatoma. Ultrastructural differences are described in tumoral hepatocytes according to the grade of differentiation of the tumoral cell population. alpha-FP production appears to be restricted to moderately differentiated tumoral hepatocytes. These observations led to the hypothesis that production of alpha-FP may transiently develop either during the differentiation of tumoral hepatocytes, or during the new differentiation of nontumoral hepatocytes involved in a proliferative process.
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PMID:Tissular immunoenzymatic detection of hepatic alphafetoprotein in human hepatomas. 8 73

A variety of antigens may be detected in the serum of patients with hepatocellular carcinoma (HCC). The incidence and distribution of five antigens in 37 HCC and their relation to each other in a given tumor was examined by the peroxidase-antiperoxidase technique using formalin-fixed paraffin-embedded tissues. alpha 1-Antitrypsin was frequently expressed in HCC (73 per cent of cases), whereas alpha-fetoprotein and carcinoembryonic antigen were less common. HBsAg, but not HBcAg, was observed in tumor cells in seven of nine HCC from HBsAg-positive patients. In 20 HCC (54 per cent), two or more antigens, most frequently alpha 1-antitrypsin and alpha-fetoprotein, were detected. Double staining for simultaneous localization of two antigens in the same tissue section revealed that different antigens were usually present in different tumor cells, although some cells displayed two antigens simultaneously. These findings suggest that hepatocellular carcinoma cells are functionally heterogeneous, even if they appear histologically monomorphic.
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PMID:Distribution of five antigens in hepatocellular carcinoma. 8 43

The bilirubin-binding ability of human alpha-fetoproteins, which were purified from fetal cord serum and from ascites fluid of a hepatoma-bearing patient, was examined by the difference spectrum and the Jacobsen peroxidase methods. The difference spectrum observed as a result of the specific binding of bilirubin to alpha-fetoprotein had a maximum at 482 nm, and this pattern was quite similar to that observed for serum albumin. The result obtained by the difference spectrum method showed that 1 mol of each alpha-fetoprotein bound 1 mol of bilirubin at pH 8.3 and that the dissociation constants of the complexes of bilirubin with fetal alpha-fetoprotein and hepatoma-derived alpha-fetoprotein were 2.6 x 10(-7) and 5.0 x 10(-7) M, respectively. The Jacobsen enzymatic method using horseradish peroxidase gave the same values for molar binding ratios and similar dissociation constants, 7.1 x 10(-7) M for fetal alpha-fetoprotein and 7.4 x 10(-7) M for hepatoma-derived alpha-fetoprotein. These results indicate that alpha-fetoprotein may function as a carrier protein for bilirubin as has been shown for serum albumin.
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PMID:alpha-Fetoprotein as a carrier protein in plasma and its bilirubin-binding ability. 8

HBsAg has been sought by light microscopy in liver specimens from patients with cirrhosis (79 cases) and hepatoma (99 cases). The study was carried out on fixed material using orcein staining, immunoperoxidase technique and indirect immunofluorescence. HBsAg was detected in the serum by radio-immunoassay (RIA) using Ausria II-125 in 38 patients with cirrhosis and in 36 with hepatoma. In the 38 seropositive cases of cirrhosis HBsAg-positive cells were observed in 31 (81.6%) by the orcein staining and in 32 (84.2%) by the peroxidase and immunofluorescence staining. Among the 36 seropositive patients with hepatoma, HBsAg was detected in the surrounding non-neoplastic part of the liver, cirrhotic or not, in 30 (83.3%) by orcein staining and in 34 (94.4%) by the immunoperoxidase method and immunofluorescence. Positive solitary-cells were seen occasionally in the tumor tissue in 16 cases using orcein, in 9 using peroxidase and in 7 by fluorescence, out of the 36 seropositive patients with hepatoma. The results of this study do not support the hypothesis of a direct oncogenic effect of HBsAg on the liver cells, since this antigen was detected mainly in the non-neoplastic part of the liver tissue and only occasionally in the tumor cells. Of the 63 cases of seronegative hepatoma, 3 showed some round orcein-positive inclusion bodies in the cytoplasm of the neoplastic and the non-neoplastic cells; these bodies were not stained by the two immunological methods.
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PMID:Detection of hepatitis B surface antigen in fixed tissues of patients with cirrhosis and hepatoma. 23 Jun 34

The fate of lectin labeled internalized plasma membrane in the ascites tumor form of the Chang rat hepatoma growing under in vivo and in vitro conditions was investigated cytochemically. Ascites cells were incubated in Convanavalin A (Con A) and horseradish peroxidase (PO), either with or without prior glutaraldehyde fixation and subsequently treated with 3',3-diaminobenzidine. In cells fixed before Con-A-PO labeling the reaction product was localized as a continuous and even layer upon the external surface of the plasma membrane. If unfixed cells were treated with Con A, coupled with PO at 4 degrees C and reincubated in phosphate buffered saline at 37 degrees C for varying periods of time, the Con-A-PO layer was of irregular thickness. In as little as 15 min of reincubation endocytotic vesicles containing PO positive material were closely associated with GERL components of the Golgi Apparatus. Localization of acid phosphatase (ACPase) within GERL vesicles, similar in size and location to those containing Con-A-PO reaction product, indicates that the Con-A-PO labeled vesicles may be a component of the Golgi apparatus in hepatoma cells.
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PMID:Cytochemical localization of lectin labeled vesicles in GERL region of hepatoma ascites cells. 38 67

The mechanism of the cytostatic action of dimerized ribonuclease A toward cultured hepatoma cells was investigated. A decrease in mitotic index, modifications of adsorptive properties of the pericellular membrane and inhibition of the degradation of two different proteins taken up by endocytosis are the first cell functions to be affected by the dimer. This effect on protein digestion is not due to an inhibition of proteolytic enzymes. The intracellular localization of exogenous protein and of ribonuclease dimer was studied by cell fractionation. When proteins (horseradish peroxidase or rabbit immunoglobulin G) are taken up by control hepatoma cells, they are first associated with phagosomes equilibrating at a lower density than lysosomes; their density distribution gradually becomes similar to that of lysosomes. When cells are pre-exposed to ribonuclease dimer, this modification of the density distribution as a function of time no longer occurs, although these proteins are still intracellular, as indicated by fractionation by differential centrifugation. During the first hour after addition of ribonuclease dimer, kinetic studies show an increased fixation of peroxidase to the cell membrane. Protein release into the culture medium is also increased. These results can be explained either by an absence of fusion between phagosomes and lysosomes, or by an inhibition of the discharge of peroxidase adsorbed to the phagosomal membrane after fusion.
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PMID:Inhibition of the discharge of endocytosed protein from phagosomes into lysosomes in hepatoma cells exposed to dimerized ribonuclease A. 44 21

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.
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PMID:Endocytosis and chloroquine accumulation during the cell cycle of hepatoma cells in culture. 51 30

An antigen-antibody complex of horseradish peroxidase, peroxidase-antiperoxidase (PAP), was found to selectively bind to Mallory bodies (MBs). Specific PAP binding to MBs was consistently demonstrated in liver sections from 14 patients with alcoholic cirrhosis and from one patient with hepatoma. Mallory bodies in isolated fractions also bound PAP. No structures stained with PAP in six control sections. The PAP-binding method is useful in the identification of MBs in situ and in isolated fractions. The nature of the affinity of MBs for PAP is not known, but it is postulated that nonspecific protein-immunoglobulin binding is involved.
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PMID:Peroxidase-antiperoxidase complex. Binding by Mallory bodies in unfixed tissue. 98 79

The distribution of the Lens culinaris lectin receptors on normal rat liver cells, on rat liver cells in vivo transformed by diethylnitrosamine and on Zajdela ascites hepatoma cells of the rat is investigated by means of the Lens culinaris lectin-peroxidase method and by ferritin conjugated Lens culinaris lectin. The normal rat liver cells show a continuous labeling at the outer membrane surface by the lectin complexes, whereas the transformed rat liver cells exhibit a strong tendency for patchy distribution of the cell surface label. The discontinuous cell surface label in the transformed rat liver cells is obviously caused by an internalization of plasma membrane areas. The importance of these morphological findings in their relationship to Lens culinaris lectin mediated agglutination of rat liver cells and the membrane fluidity in general are discussed. In the experiments no hints to a rotation of the Lens culinaris lectin receptors from the outer membrane surface to the inner membrane surface of rat liver cells can be found.
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PMID:Lens culinaris lectin receptors in the plasma membrane of rat liver cells: comparative electron microscopic studies on normal cells, on cells in vivo transformed by diethylnitrosamine and on Zajdela ascites hepatoma cells. 123 3


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