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)

Several hepatoma cell lines and hepatic ascite tumour cells were studied for the presence of glycoprotein ligands of an endogenous lectin, the "Cerebellar Soluble Lectin" (CSL). This lectin is also present in hepatocytes in vivo and in vitro and can be detected biochemically and immunologically. In transformed cells, the level of CSL glycoprotein ligands is increased 50-fold as compared to the control cells. Such an increase is not observed for the ligands of the plant lectin, concanavalin A, which is, as CSL, a D-mannose-binding lectin. These results indicated that the changes in glycans during malignant transformation, in these cells, is specifically important for minor glycans binding to CSL.
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PMID:Malignant transformation in hepatocytes is associated with the general increase of glycoprotein ligands specifically binding to the endogenous lectin CSL. 193 33

Wheat germ agglutinin binding to a rat hepatoma cell line dRLa 74 treated with concanavalin A was studied. It increased depending on the concanavalin A concentration in the culture medium. The cells exhibited about twofold increase in wheat germ agglutinin-binding when pretreated with 50 micrograms/ml of concanavalin A for 48 h. The wheat germ agglutinin binding sites were shown to be localized at the cell surface by lectin-histochemistry. Wheat germ agglutinin blotting of microsomal membrane proteins showed a broad wheat germ agglutinin-reactive band with an apparent molecular weight of 90 to 100 kDa. Loss of wheat germ agglutinin binding to dRLa 74 cells and the glycoprotein after neuraminidase treatment suggested that wheat germ agglutinin reacted with cell surface sialyl residues of dRLa 74 cells. The induced change was reversible. Increased wheat germ agglutinin binding returned to the pretreatment level when the concanavalin A-treated cells were subcultured in the absence of concanavalin A. These observations suggest that environmental factors interacting with tumor cell surface sugar moieties may induce reversible epigenetic changes on cell surface carbohydrate structures.
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PMID:Increase in cell surface wheat germ agglutinin binding in a rat hepatoma cell line dRLa 74 treated with concanavalin A. 196 34

The third component of complement (C3) plays key roles in complement activation of both the classical and alternative pathways. The liver is the major site of C3 synthesis; monocytes, B-lymphocytes and leukemic cell lines of the myeloid lineage also synthesize C3. Here we report that the C3 gene is inactive in fresh T-cells, but active in T-cells treated with the lectin phytohemagglutinin (PHA). Northern blot hybridization studies show that PHA-activated T-cells and all the T-cell lines tested express the 5.3 kb RNA transcript reported for C3 in HepG2, a hepatoma cell line, and monocytes. We used radioimmune precipitation followed by polyacrylamide gel electrophoresis to show that PHA-stimulated T-cells and T-cell lines, which are not infected with the human T-lymphotropic virus (HTLV), synthesize and release C3 proteins with molecular masses of 185, 115 and 80 kD; HTLV-infected T-cell lines release C3 proteins of 170, 115 and 70 kD. In contrast, monocytes produced C3 proteins of 115 and 70 kD similar to the serum form of this protein. The role of T-lymphocyte C3 and the implications of HTLV-infection are discussed.
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PMID:Synthesis of the third component of complement (C3) by lectin-activated and HTLV-infected human T-cells. 197 21

In Madin-Darby canine kidney (MDCK) cells, specific plasma membrane binding of [125I]insulin was undetectable. Correspondingly, neither insulin-stimulated incorporation of [14C]glucose into glycogen nor insulin-induced uptake of radiolabeled alpha-aminoisobutyrate ([ 3H]AIB) could be demonstrated. These results suggested that MDCK cells lack specific cell surface insulin receptors. To further examine this question intact MDCK cells were preincubated with antireceptor serum and subsequently labeled with [125I]protein A; however, insulin receptors were not detected. Control H4 hepatoma cells bound insulin, responded with increased glycogen synthesis and amino acid uptake, and possessed immunologically recognizable insulin receptor components. The insulin-associated response of stimulated [3H]AIB uptake was induced in MDCK cells by the insulinomimetic lectins concanavalin A (130-140% of basal value at concentrations of 10-40 micrograms/ml) and wheat germ agglutinin (140-160% of basal value at concentrations of 10-30 micrograms/ml). This stimulation was abolished by the respective lectin-specific monosaccharides D-mannose and N-acetyl-D-glucosamine. Together, these data indicate that the insulin-like activity of concanavalin A and wheat germ agglutinin can be elicited in MDCK cells even in the apparent absence of specific plasma membrane insulin-binding sites.
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PMID:Effect of wheat germ agglutinin and concanavalin A on insulin binding and response by Madin-Darby canine kidney cells. 217 60

The use of conditional mutants as a genetic approach to study protein secretion in mammalian cells requires the isolation of a large number of mutants. Because a procedure for the direct selection of mutants with secretion defects is not available, their isolation depends upon the selective enrichment of mutant phenotypes in a cell population. We have devised an enrichment strategy in which rat hepatoma cells unable to replace surface membrane receptors of a plant lectin, concanavalin A, are resistant to the cytotoxic effects of this lectin when administered at a nonpermissive temperature. This treatment yields a population highly enriched in cells that demonstrate temperature-sensitive secretion. Therefore, this selection strategy has important application in isolating temperature-sensitive mutants for use in the study of the mammalian cell secretion pathway.
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PMID:Selective enrichment for temperature-sensitive secretion mutants of mammalian cells using plant lectin, concanavalin A. 221 19

Lymphocytes were propagated with interleukin 2 from liver tissue removed at transplantation from patients with primary biliary cirrhosis or autoimmune chronic active hepatitis. Phenotypic analysis of the cultured lymphocytes as well as the infiltrating cells in situ indicated that the culture technique did not select for a particular phenotype. Eight cultures were tested for cell-mediated lympholysis activity against a bile duct tumor line as well as a hepatocellular carcinoma line, but no specific killing was seen. In addition, no natural killer activity was detected. However, the lymphocyte cultures were able to kill the targets in a lectin-dependent cytotoxicity assay, indicating their cytolytic effector activity. Preliminary studies have demonstrated that lymphocytes extracted from hepatic tissue and hilar lymph nodes from a patient with primary biliary cirrhosis proliferated in response to autologous biliary epithelial cells. These methods might be useful in studying the pathogenesis of primary biliary cirrhosis and other liver diseases with autoimmune features.
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PMID:Propagation and characterization of lymphocytes infiltrating livers of patients with primary biliary cirrhosis and autoimmune hepatitis. 235 71

alpha-Fetoprotein specimens were prepared from the sera of four patients with hepatocellular carcinoma. The lentil lectin-reactive and lectin-nonreactive variants of this glycoprotein were also prepared from the serum of one of the four patients by affinity chromatography with immobilized lectin. The correlation between the carbohydrate structure of these compounds and their reactivity in crossed immuno-affinoelectrophoresis with lentil lectin was studied by chemical analysis and affinity chromatography of the glycopeptides with lectin columns. It was found that the lentil lectin-reactive variant contained a carbohydrate chain of the fucosylated biantennary complex type. These data together with previous findings indicate that most of the patients with hepatocellular carcinoma have an elevated serum concentration of fucosylated alpha-fetoprotein.
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PMID:Fucosylation of serum alpha-fetoprotein in patients with primary hepatocellular carcinoma. 241 Dec 92

Human squamous carcinoma (COLO-16) cells release factors which specifically stimulate the synthesis of major acute-phase plasma proteins in human and rodent hepatic cells. Anion exchange, hydroxyapatite, lectin, and gel chromatography of conditioned medium of COLO-16 cells result in separation into three distinct forms of hepatocyte-stimulating factors (designated HSF-I, HSF-II, and HSF-III) with apparent molecular weights of 30,000, 50,000 and 70,000, respectively. None of the preparations contains detectable amounts of thymocyte-stimulating activity. Each of the three HSF forms stimulates the accumulation of mRNA for alpha 1-antichymotrypsin in the human hepatoma cell line, HepG2. When the same factors were added to primary cultures of adult rat hepatocytes, the expression of the same set of plasma proteins was modulated as by nonfractionated medium. The hormonally induced accumulation of mRNA for acute phase proteins is qualitatively comparable to that occurring in the liver of inflamed rats. Unlike in human cells, in rat liver cells dexamethasone acts additively and synergistically with HSFs. The only functional difference between the three HSF forms lies in the level of maximal stimulation. HSF-I represents the predominant form produced by normal human keratinocytes and closely resembles in molecular size and isoelectric point the activity produced by activated peripheral blood monocytes while the larger molecular weight forms are more prevalent in human as well as mouse squamous carcinoma cells. The observation that HSFs from different sources elicit essentially the same pleiotropic response in hepatic cells led to the hypothesis that the species-specific reaction of adult liver cells to inflammatory stimuli is pre-programmed and that the function of any HSF is to trigger and tune the execution of this fixed cellular process.
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PMID:Regulation of major acute-phase plasma proteins by hepatocyte-stimulating factors of human squamous carcinoma cells. 241 29

Using a modified method of concanavalin A (Con A), lentil lectin (LCH) or phytohemagglutinin-E (PHA-E) affinity crossed-line immunoelectrophoresis (ACIE), we studied alpha-fetoprotein (AFP) subfractions in 69 sera, including 58 from patients with primary liver cancer and 11 from patients with hepatic metastasis of gastric cancer. We found that Con A non-reactive subfraction (type b) or LCH weakly-reactive subfraction (type B) was more frequently detected in metastatic liver cancer, as compared with liver cancer hepatoma. The amount of Con A non-reactive subfraction (type b) or of PHA-E reactive subfraction (type X) was significantly higher in case of metastatic liver cancer than in primary liver cancer. Since different affinities between AFP and lectins are due to the microheterogeneity in AFP sugar chain, our findings suggest that AFP in primary liver cancer and metastatic liver cancer is glycosylated in a different manner. It is also indicated that different patterns of AFP subfractions identified by the combination of Con A, LCH or PHA-E ACIE facilitate a differential diagnosis of these hepatic malignancies.
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PMID:Serum alpha-fetoprotein subfractions in hepatic malignancies identified by different reactivities with concanavalin A, lentil lectin or phytohemagglutinin-E. 242 Oct 34

Allomyrina dichotoma lectin (allo A) with a specificity to beta-D-galactose was used to fractionate human alpha-fetoprotein (AFP) by affinity electrophoresis. AFP from cord sera and serum of a patient with fulminant hepatitis showed single bands with a high affinity for allo A. Some patients with hepatocellular carcinoma and patients with gastric cancer and yolk sac tumor had two additional AFP bands, one weakly reactive and the other nonreactive with allo A. Patterns of AFP bands obtained with Ricinus communis agglutinin-I (RCA-I) and erythroagglutinating phytohemagglutinin from Phaseolus vulgaris were entirely different from those obtained with allo A. Of the two common bands reactive with RCA-I, the weakly reactive one was relatively intense in some malignant patients and the strongly reactive one was detected in patients with extrahepatic tumors. Thus, affinity electrophoresis with those lectins provides a potentially useful adjunct for the discrimination between benign and malignant conditions with increased serum levels of AFP.
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PMID:Allomyrina dichotoma lectin-nonreactive alpha-fetoprotein in hepatocellular carcinoma and other tumors: comparison with Ricinus communis agglutinin-I. 242 91


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