Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

By immunoperoxidase histochemical staining of formalin-fixed paraffin-embedded sections, the production of alpha-fetoprotein(AFP), albumin(ALB), transferrin(TF), alpha-1-antitrypsin(AAT), and human chorionic gonadotropin(HCG) was examined in 35 operatively resected stomach cancers with elevated serum AFP levels (higher than 20 ng/ml as determined by radioimmunoassay). Cells positive for AFP were found in 19 cases (54%). In 29 cases (83%), some tumor cells contained normal serum proteins (ALB, TF, or AAT). All 19 tumors with AFP-positive cells also stained positively for two or three kinds of normal serum proteins. In some cases, AFP and normal serum proteins were localized in the same cells. There were two cases in which metastatic tumors produced AFP, whereas the primary sites did not. In nine cases (26%), HCG was present in tumor cells and HCG- and AFP-positive cells were coexistent in six tumors. Histologic examination of AFP-producing stomach tumors revealed medullary or papillotubular arrangements with marked nuclear atypia and eosinophilic granular or clear cytoplasms containing no glycogen or mucin. Some tumors with medullary patterns resembled liver cell carcinomas. Concordant phenotypic expression of AFP and normal serum protein production appears to be a general feature of AFP-producing tumors such as liver cell carcinoma, yolk sac tumor, and stomach cancer.
 ...
PMID:Production of alpha-fetoprotein, normal serum proteins, and human chorionic gonadotropin in stomach cancer: histologic and immunohistochemical analyses of 35 cases. 616 23

Clonal cell lines were isolated from rat hepatoma McA-RH7777 to study expression of alpha-fetoprotein (AFP) in these clones. AFP contained by the cells was determined by immunofluorescent and immunoperoxidase staining, while AFP secreted into the medium by aggregate-hemagglutination and immunoisotachophoresis. The existence of the clones that drastically differ in the intensity of AFP synthesis was demonstrated, with these clones being implicated in the monitoring of AFP synthesis. The differences between the clones gradually diminished in the course of long-term cultivation. It was also shown that the clones under consideration secreted, apart from AFP, at least 8 proteins of adult rat serum. One of the proteins was identified as transferrin. No albumin was detected in the cultural media tested. The level of AFP production did not correlate with the synthesis of other serum proteins and thus seems likely to be controlled by an independent mechanism.
 ...
PMID:[Independence of alpha-fetoprotein expression from production of adult rat serum proteins in hepatoma McA-RH7777]. 617 Mar 66

alpha-Fetoprotein (AFP) synthesis was studied in the presence and absence of glucocorticoids in rat hepatoma Mc-A-RH-7777 cells. Radioimmunoassay of media from cell cultures grown in the presence of glucocorticoid (dexamethasone or cortisol) showed a reduction in AFP, an increase in albumin, and no significant change in transferrin accumulation, as compared to controls. Labeling experiments with L-[35S]methionine indicated that in both cells and media of dexamethasone-treated cultures there was a 50--80% reduction in polypeptide precipitated by anti-AFP serum, as compared with controls; no change was seen in polypeptide precipitated by anti-transferrin serum. Pulse and pulse-chase experiments demonstrated that dexamethasone inhibited the synthesis of AFP but not its secretion. The half-time for secretion of AFP in the presence and absence of dexamethasone was 43 min.
 ...
PMID:Inhibition of synthesis of alpha-fetoprotein by glucocorticoids in cultured hepatoma cells. 617 43

Four diploid human cell types (lymphocytes, fibroblasts, amniotic fluid cells, and hepatocytes) were fused to mouse hepatoma cells, HH. HH synthesized and secreted several liver-specific gene products including albumin, transferrin, and alpha-fetoprotein. The resulting interspecific hybrids were compared to determine whether or not the pattern of human hepatic gene expression was similar when these various cells were fused with the mouse hepatoma line. The expression of six human hepatic genes was examined, including albumin, alpha-fetoprotein, ceruloplasmin, transferrin, alpha-1-antitrypsin, and haptoglobin. Albumin was most frequently expressed while alpha-fetoprotein was not detected in any of the hybrids studied. The patterns of expression of human serum proteins differed between the hybrid series. Hybrids derived from human fibroblasts produced primarily albumin, while those derived from lymphoblastoid cells and amniocytes had a higher frequency of clones secreting alpha-1-antitrypsin. The findings reported here suggest that the frequency of hybrid clones expressing human hepatic gene products and the array of proteins produced are influenced by the histogenetic state of the human parental cell type.
 ...
PMID:Expression of human hepatic genes in somatic cell hybrids. 618 Apr 90

Independent hybrid clones resulted from the whole cell and microcell-mediated transfer of hamster or mouse fibroblast chromosomes into mouse hepatoma XXIIa cells. The fusion was promoted with PEG, ethidium bromide alone, or in combination with HAT and ouabain, was used for selecting the hybrids. Using indirect immunoautoradiography, three clones (one intra- and one interspecies microcellular; one interspecies, whole cell fusion) have been found to express their hepatic function to synthesize transferrin. The liver specific protein--albumin--was extinguished in all the hybrid combinations. Possible mechanisms of gene expression are discussed. The hybrids selected could be used for mapping chromosomes, coding proteins, as well as for studying regulation in the tandem of albumin and alpha-fetoprotein genes in the mouse genome. The microcell mediated chromosome transfer into differentiated cells has been used to construct original genetical combinations of regulatory and structural elements of the mouse genome.
 ...
PMID:[Ability of the cells of intra- and interspecific hybrids of murine hepatoma XXIIa to synthesize the serum proteins albumin and transferrin]. 619 75

We have found a new 111In-bleomycin complex (BLMC), which has high affinity to tumor, does not bind to transferrin and is stable in vivo. Distribution in animals bearing glioma, hepatoma, or mammary adenocarcinoma at 48 hours showed: the ratios of tumor to blood, brain, heart, lung, liver, pancreas, stomach, and femur were 1.4-22.4 times as high for 111In-BLMC as for 67Ga-citrate. In mammary adenocarcinoma, 111In-BLMC bound more to viable and 57Co-Bleomycin (BLM) more to necrotic tumor. In viable tumor, the concentration of 111In-BLMC was similar to that of 57Co-BLM. The ratios of tumor to stomach and pancreas were higher, to blood, brain, muscle, heart, and femur were lower for 111In-BLMC than those for 57Co-BLM. The ratios of tumor to lung, liver, spleen, skin, and kidney were similar for the two compounds. Tumors were imaged more distinctly with the new 111In-BLMC and 57Co-BLM than with 67Ga-citrate. 111In-BLMC is promising for tumor imaging.
 ...
PMID:A new tumor imaging agent--111In-bleomycin complex. Comparison with 67Ga-citrate and 57Co-bleomycin in tumor-bearing animals. 620 27

1- Deoxynojirimycin is a specific inhibitor of glucosidases I and II, the first enzymes that process N-linked oligosaccharides after their transfer to polypeptides in the rough endoplasmic reticulum. In a pulse-chase experiment, 1- deoxynojirimycin greatly reduced the rate of secretion of alpha 1-antitrypsin and alpha 1-antichymotrypsin by human hepatoma HepG2 cells, but had marginal effects on secretion of the glycoproteins C3 and transferrin, or of albumin. As judged by equilibrium gradient centrifugation, 1- deoxynojirimycin caused alpha 1-antitrypsin and alpha 1-antichymotrypsin to accumulate in the rough endoplasmic reticulum. The oligosaccharides on cell-associated alpha 1-antitrypsin and alpha 1-antichymotrypsin synthesized in the presence of 1- deoxynojirimycin , remained sensitive to Endoglycosidase H and most likely had the structure Glu1- 3Man9GlcNAc2 . Tunicamycin, an antibiotic that inhibits addition of N-linked oligosaccharide units to glycoproteins, had a similar differential effect on secretion of these proteins. Swainsonine , an inhibitor of the Golgi enzyme alpha-mannosidase II, had no effect on the rates of protein secretion, although the proteins were in this case secreted with an abnormal N-linked, partially complex, oligosaccharide. We conclude that the movement of alpha 1-antitrypsin and alpha 1-antichymotrypsin from the rough endoplasmic reticulum to the Golgi requires that the N-linked oligosaccharides be processed to at least the Man9GlcNAc2 form; possibly this oligosaccharide forms part of the recognition site of a transport receptor for certain secretory proteins.
 ...
PMID:Glucose removal from N-linked oligosaccharides is required for efficient maturation of certain secretory glycoproteins from the rough endoplasmic reticulum to the Golgi complex. 623 87

A human hepatoma cell line, HuH-7, which was established from a hepatocellular carcinoma, was found to replicate continuously in a chemically defined medium when the medium was supplemented with Na2SeO3. The cells grew better in this medium than in serum-containing medium without any adaptation period. Other established human hepatoma and hepatoblastoma cell lines, HuH-6 cl-5, PLC/PRF/5, huH-1, and huH-4, also grew in the defined medium. Although HLEC-1 cells failed to proliferate continuously with Na2SeO3 alone, they grew if a cell-free conditioned medium from HuH-7 cells was added to the medium. These cell lines, except the HLEC-1 cell line, produced the following human plasma proteins among those examined: albumin, prealbumin, alpha 1-antitrypsin, ceruloplasmin, fibrinogen, fibronectin, haptoglobin, hemopexin, beta-lipoprotein, alpha 2-macroglobulin, beta 2-microglobulin, transferrin, lipoprotein, alpha 2-macroglobulin, beta 2-microglobulin, transferrin, Complement Components 3 and 4, and alpha 1-fetoprotein. Beside plasma proteins, the media from HuH-7, HuH-6 cl-5, PLC/PRF/5, and huH-1 contained anti-carcinoembryonic antigen-reactive proteins, and those from PLC/PRF/5, huH-1, and huH-4 medium contained hepatitis B surface antigen. These proteins were detected during periods of serial cultivation over 9 months under the above culture conditions. The hepatoma cell lines grown in the fully defined synthetic medium may provide a new approach for investigating the growth and metabolism of human hepatoma cells in vitro.
 ...
PMID:Growth of human hepatoma cells lines with differentiated functions in chemically defined medium. 628 15

Receptor-mediated endocytosis of specific ligands is mediated through clustering of receptor-ligand complexes in coated pits on the cell surface, followed by internalization of the complex into endocytic vesicles. We show that internalization of asialoglycoprotein by HepG2 hepatoma cells is accompanied by a rapid (t1/2 = 0.5-1 min) depletion of surface asialoglycoprotein receptors. This is followed by a rapid (t1/2 = 2-4 min) reappearance of surface receptors; most of these originate from endocytosed cell-surface receptors. The loss and reappearance of asialoglycoprotein receptors is specific, and depends on prebinding of ligand to its receptor. HepG2 cells also contain abundant receptors for both insulin and transferrin. Endocytosis of asialoglycoprotein and its receptor has no effect on the number of surface binding sites for transferrin or insulin. We conclude that binding of asialoglycoprotein to its surface receptor triggers a rapid and specific endocytosis of the receptor-ligand complex, probably due to a clustering in clathrin-coated pits or vesicles.
 ...
PMID:The asialoglycoprotein receptor internalizes and recycles independently of the transferrin and insulin receptors. 629 85

Human hepatoma cells, infected by vesicular stomatitis virus, offer a good system to study simultaneously the intracellular localization of a well defined transmembrane glycoprotein (VSV-G), a secretory glycoprotein (transferrin), and a nonglycosylated secretory protein (albumin). We used monospecific antibodies in combination with 5- and 8-nm colloidal gold particles complexed with protein A to immunolabel these proteins simultaneously in thin frozen sections of hepatoma cells. VSV-G, transferrin, and albumin are present in the same rough endoplasmic reticulum cisternae, the same Golgi compartments, and the same secretory vesicles. In the presence of the ionophore monensin intracellular transport is blocked at the trans cisternae of the Golgi complex, and VSV-G, transferrin, and albumin accumulate in dilated cisternae, which are apparently derived from the trans-Golgi elements. Glycoproteins, synthesized and secreted in the presence of monensin, are less acidic than those in control cultures. This is probably caused by a less efficient contact between the soluble secretory proteins and the membrane-bound glycosyltransferases that are present in the most monensin-affected (trans) Golgi cisternae.
 ...
PMID:Vesicular stomatitis virus glycoprotein, albumin, and transferrin are transported to the cell surface via the same Golgi vesicles. 631 44


<< Previous 1 2 3 4 5 6 7 8 9 10