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Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell-substratum adhesion of rat hepatocytes was inhibited by antisera raised against purified plasma membranes of rat liver (anti-liver-antiserum) and Morris hepatoma 7777 (anti-hepatoma-antiserum). It is assumed that substances which block the adhesion-inhibiting activity of the antisera are involved in cell-substratum adhesion. Adhesion-involved molecules of rat liver monitored as 'blocking activity' were compared with those of Morris hepatoma 7777 and 9121. They were found to be integral membrane glycoproteins, which could be solubilized only by detergents. Fractionation of plasma membrane extracts by size exclusion HPLC revealed two blocking activity peaks representing molecules involved in the adhesion to plastic (P-AIM) and collagen (C-AIM). In rat liver both adhesion-involved molecules were found; yet P-AIM seemed to be the major type of adhesion-involved molecule. In the relatively well differentiated Morris hepatoma 9121 also both types were detected. In membrane extracts of the high malignant and poorly differentiated Morris hepatoma 7777, however, no P-AIM but only C-AIM were found. Estimation by size exclusion HPLC revealed molecular weights of 120 kD for C-AIM and approx. 105 kD for P-AIM. On SDS gel electrophoresis proteins in the region of 95 kD were found in C-AIM containing fractions, whereas proteins of 105 kD are likely candidates for P-AIM.
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PMID:Integral membrane antigens involved in cell-substratum adhesion of hepatocytes and hepatoma cells. 670 41

Cell-substratum adhesion of rat hepatocytes was inhibited by antisera raised against plasma membranes of liver (anti-liver antiserum) and Morris hepatoma 7777 (anti-hepatoma antiserum). Similar concentrations of both antisera inhibited adhesion on collagen. Anti-liver antiserum also inhibited the adhesion of hepatocytes on plastic, whereas anti-hepatoma antiserum was only able to inhibit the adhesion on collagen completely. These results suggest the existence of at least two different adhesion-involved molecules. Cells adhere to plastic by means of both molecules, whereas adhesion on collagen is mediated by only one of them. The results further suggest that hepatoma cells lost the molecule involved in adhesion on plastic.
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PMID:Different adhesion inhibiting activities of antisera against plasma membranes of liver and Morris hepatoma 7777. 672 50

Iron, as ferric nitrilotriacetate or ferric ammonium citrate, was administered to rat hepatoma cells (H4AZC2) that were grown in serum-containing media or in hormone-supplemented defined media on collagen matrices. High levels of iron either retarded growth or were cytotoxic, so conditions were established for maximum iron loading where cells survived at near normal growth rates. In all cases, cells exposed to iron produced more ferritin than those grown in its absence, and elevated ferritin levels were paralleled by higher intracellular iron contents. Cells grown in serum-free media, however, took up iron more rapidly than corresponding cells in serum-supplemented media, and intracellular iron and ferritin also reached much higher levels. During exponential growth stages, for example, ferritin levels in iron-stimulated cells were 35-fold greater than those in control cells. These results indicate that transferrin is not required as an iron donor as the inorganic iron was taken up effectively and utilized to stimulate ferritin synthesis. Twenty-four hours after iron administration, endocytotic mechanisms were evident by the appearance of coated vesicles and pits and visible cytoskeletal structures. Subsequently, clusters of iron micelles appeared in the cell. Ferritin isolated from iron-overloaded cells were rich in L-type subunits, but newly synthesized ferritins in iron-stimulated or control cells had almost equivalent amounts of heavy and light subunit constituents.
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PMID:Iron uptake and regulation of ferritin synthesis by hepatoma cells in hormone-supplemented serum-free media. 683 99

The ability of retinoids to prevent or alter the course of experimental tumorigenesis is well established. We have extended these observations to include effects on establishment of tumors and tumor metastases. A diet containing excess retinyl acetate fed to rats prior to injection of a metastatic line of transplantable hepatoma, prevented establishment of secondary tumor foci while 75% of the animals fed adequate retinyl acetate showed pulmonary metastases. Metastatic ability may be related to the ability to bind fibronectins, proteins that link cells to an underlying stroma. Findings suggest involvement of higher gangliosides in the attachment of cells to a fibronectin-collagen complex. Prior to metastasis, hepatoma lines become depleted in the putative fibronectin receptor gangliosides as an end result of a complex cascade of altered glycosyltransferase activities. After metastasis, fibronectin receptors are apparently restored in those secondary tumor foci that become established. Analyses suggest that excess vitamin A may prevent the reappearance of fibronectin receptor gangliosides so that secondary tumor foci do not establish.
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PMID:Glycosylation reactions and tumor establishment: modulation by vitamin A. 694 82

Examination of 51 human liver specimens with the modified Kupffer's gold impregnation method confirmed the presence and distribution of fat-storing cells in various kinds of diseased livers such as fatty liver, acute centrolobular necrosis, subacute massive necrosis and cirrhosis as well as in liver cell carcinoma. In normal liver, gold-reactive fat-storing cells were distributed in the central area or diffusely in lobules. In the liver with marked fatty change and obstructive jaundice, presence of fat-storing cells was able to be clarified by this method. In cases of acute hepatocellular necrosis, the necrotic areas contained a large number of fat-storing cells in contrast to adjacent areas. In cases of subacute massive hepatic necrosis and cirrhosis, the areas with abundant newly formed collagen fibers (type III collagen) contained many gold-reactive fat-storing cells. In the septa consisting of dense type I collagen fibers, by contraries, fat-storing cells were hardly visible. The features suggested that fat-storing cells are closely related to intralobular fibrogenesis. In one case of liver cell carcinoma, there were many gold-reactive fat-storing cells in tumour tissue.
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PMID:Pathological study on gold impregnation of fat-storing cells in human liver. 723 21

Epithelial cells of normal rat liver origin (strain RL34) synthesized the alpha 1 peptide of type I collagen. In nononcogenic cultures (RL34 and RL34EC) and a marginally oncogenic culture (RL34HII), the peptide was continuously secreted from the proliferating cells. Part of the soluble peptide was incorporated into the intercellular matrix of contact-inhibited cells after confluency, while the remainder was degraded. The intercellular matrix contained characteristic collagen fibrils which were argyrophilic and revealed a 64 nm axial periodicity. Epithelial cells of an oncogenic culture (RL34HT) secreted procollagen into the medium continuously throughout their proliferative phases and were unable to accumulate collagen fibrils in the intercellular matrix. The depletion of collagen accumulation in the hepatocarcinoma cell culture was ascribed to lack of the binding of native collagen molecules to the cell membrane and the persistence of high proteolytic activity on the cell surface.
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PMID:Formation of intercellular collagen matrix by cultured liver epithelial cells and loss of its ability in hepatocarcinogenesis in vitro. 732 13

Sera from 101 patients with liver disease were studied for the presence of antibodies to three types of denatured bovine collagens by passive haemagglutination assay. A high incidence and titres were found especially in chronic active hepatitis, liver cirrhosis and primary hepatoma. The incidence and titres of antibodies to Type I and Type III collagens were significantly higher than those of antibodies to Type II collagen. Analysis by gel filtration on Sephadex G-200 or absorption with anti-IgG and IgM antisera revealed that the antibodies belonged to both IgG and IgM classes. They correlated with serum gamma-globulin levels, but not with rheumatoid factor.
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PMID:Antibodies to denatured bovine collagens in sera of patients with liver disease. 738 87

Quantitative analysis has shown that the cells of mouse ascites hepatoma 22a (AH-22a) possess a very low capacity for establishing steady contacts with various solid substrata (glass, carbon, collagen). This capacity considerably increased after the first formation of cell-substratum contact and was further enhanced as a result of repeated formations of such contacts (during the passaging of AH-22a cells in a monolayer culture). The effect observed was reversible since the cells of ascites tumour that developed in syngeneic mice after intraperitoneal inoculation of AH-22a cell culture rapidly lost previously acquired high capacity for adhesion to solid substrata. These modulations of cell adhesiveness are presumably related to reversible alterations in the cell surface.
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PMID:[Contact interaction between ascitic hepatoma 22a cells and solid substrate]. 739 63

A human hepatocyte line (HHY41) was established from normal human liver tissue. This cell line was derived from a primary culture of human hepatocytes maintained between two layers of collagen gel for 4 weeks. It differs from other human hepatocyte lines in that transfection with the simian virus 40 gene was not used for cellular transformation and nonhepatocellular coculture cells were not present. HHY41 cells have proliferated freely in serum and hormone-supplemented medium after more than 1 year in continuous culture, exhibiting typical morphological characteristics of hepatocytes. HHY41 cells retain glucose-6-phosphatase activity. They also retain the ability to secrete liver-specific proteins such as albumin, transferrin, and alpha-fetoprotein. Northern blot analysis confirmed the presence of albumin mRNA. Cytochromes P450 induced by polycyclic aromatic hydrocarbons are maintained in these cells. Detection of cell surface antigens revealed that HHY41 cells express alpha 1 beta 1-integrin, which is expressed by normal hepatocytes and not by bile duct epithelial cells. High-molecular-weight cytokeratin, a marker for bile duct cells, is also absent in HHY41. Cytogenetic analysis showed hyperdiploid karyotype with a consistent deletion in the short arm of chromosome 1. HHY41 can be considered a new human hepatocyte line which retains liver-specific functions of differentiated hepatocytes. Derived from normal liver tissue, not a hepatocellular carcinoma, it provides a new model system for studying the regulation of cell growth and differentiated functions in human hepatocytes.
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PMID:Establishment of a human hepatocyte line derived from primary culture in a collagen gel sandwich culture system. 749 48

A cell culture model was developed to investigate the involvement of gangliosides in cell-matrix adhesion. Two cell lines with different adhesive properties derived from solid Morris hepatoma 7777 were established. Cultured in horse serum-containing medium, the adhesive cell line (MH 7777A) adheres and spreads on uncoated culture dishes, whereas the revertant cell line (MH 7777A > N) does not adhere and grows in suspension. The adhesiveness of both cell lines is dependent on the coating protein used (none, bovine serum albumin, fibronectin or collagen I) and the horse serum concentration in the culture medium. Both cell lines, although of the same origin, differed in their ganglioside composition. The most abundant ganglioside of both MH 7777A and MH 7777A > N cell lines was fucosyl-GM1, 0.78 and 0.72 microgram per mg cellular protein, respectively. The GM3 and GD1a content of MH 7777A > N cells was significantly higher than that of MH 7777A cells. Furthermore, a matrix-dependency of the ganglioside pattern of both cell lines was demonstrated.
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PMID:Influence of extracellular matrices on ganglioside pattern of two hepatoma cell lines with different adhesive properties. 749 32


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