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)

Tissue factor pathway inhibitor (TFPI) is a plasma serine protease inhibitor that directly inhibits coagulation factor Xa and regulates blood coagulation via inhibition of factor VIIa-tissue factor enzymatic activity. We previously demonstrated that >90% of TFPI bound to a single population of low affinity binding sites on hepatoma cells (2 x 10(6) sites/cell, Kd = 30 nM), and, that following binding, the low density lipoprotein receptor-related protein (LRP) mediated TFPI uptake and degradation. We subsequently reported heparan sulfate proteoglycans (HSPGs) constitute a second receptor system involved in TFPI catabolism. In the present study, mouse embryonic fibroblasts heterozygous and homozygous-negative for disruption of the LRP gene were used to further examine the roles of LRP and HSPGs in TFPI endocytosis. We demonstrate that LRP is absolutely required for degrading 125I-TFPI. LRP heterozygous and homozygous-negative cells bind 125I-TFPI similarly, and the 39-kDa protein, an inhibitor of all known ligand interactions with LRP, does not alter 125I-TFPI binding to these cells. TFPI can be cross-linked to LRP on [35S]cysteine-labeled hepatoma and LRP-heterozygous cells but not LRP-negative cells. When HSPGs are blocked with protamine, 125I-TFPI binds in a 39-kDa protein-inhibitable manner to 41,000 high affinity sites/hepatoma cell (Kd = 2.3 nM). Blockade of HSPGs with protamine results in significantly more 125I-TFPI degradation by LRP-positive cells. TFPI can be cross-linked to LRP in the absence and presence of protamine. However, in the presence of protamine, relative to the total pool of cross-linked proteins, 5-fold more TFPI is cross-linked to LRP. Finally, we show TFPI inhibits 125I-alpha2-macroglobulin-methylamine binding to hepatoma cells and that carboxyl-terminal residues 115-319 of the 39-kDa protein inhibit both 125I-TFPI degradation and binding when binding conditions contain protamine. Together, our results suggest that while the majority of TFPI binds to cell surface HSPGs, LRP can function independently from HSPGs in the binding and uptake of TFPI.
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PMID:The low density lipoprotein receptor-related protein can function independently from heparan sulfate proteoglycans in tissue factor pathway inhibitor endocytosis. 882 19

A circulating anticoagulant was isolated from the plasma of a 42-year-old man with cirrhosis and hepatocellular carcinoma who had an unusual coagulation test profile. The patient developed a fatal coagulopathy, unresponsive to protamine therapy or plasma exchange following liver biopsy. However, at presentation, routine hemostasis assays were normal. The patient had mucocutaneous bleeding but the sole laboratory abnormality was a prolonged thrombin time (TT = 99 s, normal 25-35 s). Protamine titration indicated activity equivalent to a heparin concentration of 6-7 U/ml. Antithrombin III (AT III) antigen and activity were markedly elevated. The anticoagulant activity, purified from plasma by DEAE chromatography, was identified as a glycosaminoglycan (GAG). GAG anti-thrombin activity was completely abolished by heparin lyase III. Based on the degree of sulfation and HPLC pattern, the GAG was classified as heparan sulfate. Low levels (4 microM) of purified GAG markedly prolonged the TT (>120 s) but not the activated partial thromboplastin time (PTT) (31.4 s). In a Factor Xa assay, the GAG exhibited a potency equivalent to 0.06 U of low molecular weight heparin per nmol of uronic acid. Patients with endogenous circulating glycosaminoglycans can present with unusual laboratory coagulation test profiles. These reflect complex dysfunction of hemostasis, leading to difficulty in providing diagnosis and effective care.
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PMID:Structural characterization and functional effects of a circulating heparan sulfate in a patient with hepatocellular carcinoma. 969 91

Plasmids containing PCR-amplified hepatitis B virus e antigen (HBeAg) genes (HBeAg-MV and HBeAg-SV) were constructed and expressed in E. coli strain DH5alpha. The induced intracellular glutathione S-transferase (GST) fusion proteins of HBeAg-MV and HBeAg-SV were recovered and purified from bacterial lysates by affinity chromatography with glutathione-sepharose beads. The HBeAg-MV protein contained an additional 19 amino acids at its amino terminus. These two proteins were specifically cleaved from GST by the protease factor Xa and recognized by a monoclonal antibody against HBeAg. HBeAg-MV and HBeAg-SV were found to be the two major components of the post-modified HBcAg during viral infection. The antigenic specificities of the fusion and purified HBeAgs (factor Xa-digested) were confirmed by the Abbott HBe enzyme immunoassay (EIA) detection system. Sera from patients with confirmed hepatocellular carcinoma (HCC) specifically reacted only with HBeAg moiety of fusion proteins. HCC sera bound more strongly to the HBeAg-SV protein than to the HBeAg-MV one. This indicates that HBeAg-SV is either more antigenic than -MV or is the major target protein for the elicitation of antibody production after HBV infection. Thus, the two recombinant HBeAgs expressed and obtained in this study are appropriate immunological agents for the diagnostic detection of hepatitis B virus infection in humans.
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PMID:Immunological characterization of two major secreted forms of recombinant hepatitis B virus e antigens. 1008 91

In the present study, we established an animal model for dengue virus infection using severe combined immunodeficient mice transplanted with a human hepatocarcinoma cell line (HepG2). At 7-8 weeks after transplantation, the HepG2-grafted mice were infected intraperitoneally with dengue virus type 2 (DEN-2). A higher titer of the virus was detected in the liver and serum but not in the brain in the early stage of postinfection. When the mice showed paralysis, the highest titer of virus was detected in the serum and brain. DEN-2 antigens were also found in HepG2 cells of the liver in the early stage and some neurons of the brain in the late stage. Upon clinical examination, thrombocytopenia, prolonged partial thromboplastin time, and increased hematocrit, blood urea nitrogen, and tumor necrosis factor alpha were seen in the paralyzed mice. Moreover, mild hemorrhage in the liver and tarry stool in the small intestine were observed in some mice. Our results show some similarities to human DEN infection and this mouse model might be valuable for studying some aspects of pathogenesis of this disease.
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PMID:Development of a novel mouse model for dengue virus infection. 1054 83

We report a 71-year-old man who exhibited hepatocellular carcinoma and the inhibitor for coagulation factor V (FV). The inhibitor was found when his coagulation screening tests revealed an abnormally prolonged prothrombin time (71.1 sec) and activated partial thromboplastin time (more than 120 sec) but normal values of fibrinogen (241 mg/dl), the thrombo test (84%) and hepaplastin test (71%). In addition, FV-coagulation activity of the patient's plasma showed less than 1% of the pooled normal plasma and inhibitory activity for FV of his plasma was 32 Bethesda units. This inhibitory activity was neutralized by the addition of anti-human immunoglobulin-gamma-chain serum. The patient was treated with a fibrin sealant including human thrombin when he underwent an partial hepatectomy (32 months before onset) and received 2 doses of thrombin orally (5 months and 2 weeks before onset) to stop bleeding from phlebeurysm. Several studies have reported that the inhibitor for FV was produced after treatment with bovine thrombin containing FV as a contaminant. These findings suggest that our patient may produce an immunoglobulin specific for FV after similar stimulation of human thrombin containing FV.
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PMID:[A case positive for the inhibitor for coagulation factor V]. 1059 Jun 73

Asparaginase (ASNase) is a widely used and successful agent against childhood acute lymphoblastic leukemia (ALL). Asparaginase cleaves asparagine (Asn) to give aspartic acid and ammonia, thereby depleting free Asn in the blood. However, treatment with ASNase has been implicated in significant reduction of plasma levels of the coagulation serine protease inhibitor (serpin) antithrombin III (AT3), predisposing patients to thromboembolic complications. Our investigation was designed to delineate the biochemical mechanism of AT3 depletion that can occur in the plasma of ALL patients undergoing ASNase therapy. SDS-PAGE showed no cleavage of purified AT3 following treatment with ASNase. Furthermore, purified AT3 treated with ASNase demonstrated no decrease in inhibitory activity. Human plasma and whole blood treated with approximate therapeutic concentrations of ASNase showed no loss of AT3 activity as detected by a plasma-based factor Xa inhibition assay. Treatment of a confluent monolayer of HepG2 (hepatocarcinoma) cells with ASNase showed no gross loss in AT3 message levels detected by rtPCR. However, a decrease of cell viability was observed in cultures treated with ASNase. Interestingly, medium from HepG2 cells treated with ASNase showed a marked decrease in secretion of AT3 and another serpin, heparin cofactor II. Collectively, these data show that ASNase has no direct effect on AT3 in blood or plasma, but that ASNase may affect plasma levels of AT3 by interfering with translation and/or secretion of the protein in liver cells.
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PMID:Insight into the mechanism of asparaginase-induced depletion of antithrombin III in treatment of childhood acute lymphoblastic leukemia. 1086 29

Hepatitis B virus X protein (HBx) expressed in Escherichia coli DH5alpha by recombinant DNA technology was purified to homogeneity by use of glutathione-Sepharose beads. Immunological characterization of the recombinant HBx protein was performed. Specific binding between the anti-HBx monoclonal antibody and HBx protein showed the specificity of the recombinant HBx protein. The intact HBx protein of the factor Xa-digested glutathione S-transferase-HBx fusion protein was further purified and was used as an antigen for screening the titers of anti-HBx antibodies in sera. Titers of anti-HBx in sera from 20 patients with hepatocellular carcinoma (HCC), 20 patients with chronic hepatitis (CH), and 20 healthy individuals were evaluated by Western blotting and a quantitative enzyme-linked immunosorbent assay. The results indicated that 70% of sera from HCC patients and 5% of sera from CH patients contained antibodies with significant binding to the HBx protein. Western blotting of HBx protein in liver extracts from 20 HCC patients was also performed by using the anti-HBx monoclonal antibody. Results showed that 85% of HCC patients' liver tissues contained a specific HBx protein with the same molecular size as the purified intact HBx. Full correlation was found between anti-HBx antibody positivity in serum and HBx protein positivity in HCC tissues. The data demonstrated that the etiology of HCC is involved with hepatitis B virus (HBV) infection and that HBx in particular plays a role in the development of HBV-related HCC.
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PMID:Detection of the hepatitis B virus X protein (HBx) antigen and anti-HBx antibodies in cases of human hepatocellular carcinoma. 1466 47

The isolation, purification and structural characterization of human liver heparan sulfate are described. 1H-NMR spectroscopy demonstrates the purity of this glycosaminoglycan (GAG) and two-dimensional 1H-NMR confirmed that it was heparan sulfate. Enzymatic depolymerization of the isolated heparan sulfate, followed by gradient polyacrylamide gel, confirmed its heparin lyase sensitivity. The concentration of resulting unsaturated disaccharides was determined using reverse phase ion-pairing (RPIP) HPLC with post column derivatization and fluorescence detection. The results of this analysis clearly demonstrate that the isolated GAG was heparan sulfate, not heparin. Human liver heparan sulfate was similar to heparin in that it has a reduced content of unsulfated disaccharide and an elevated average sulfation level. The antithrombin-mediated anti-factor Xa activity of human liver heparan sulfate, however, was much lower than porcine intestinal (pharmaceutical) heparin but was comparable to standard porcine intestinal heparan sulfate. Moreover, human liver heparan sulfate shows higher degree of sulfation than heparan sulfate isolated from porcine liver or from the human hepatoma Hep 2G cell line.
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PMID:Structural characterization of human liver heparan sulfate. 1565 73

Blood coagulation factor VII (fVII) is physiologically synthesized in the liver and released into the blood. Binding of fVII to tissue factor (TF) at sites of vascular injury triggers coagulation and hemostasis. TF/fVIIa complex formation on the surface of cancer cells plays important roles in cancer biology. Although fVII is synthesized by hepatocellular carcinoma, it remained unclear how TF/fVIIa complex formation and promigratory signaling can occur for most other cancers in extravascular locations. Here, we show by reverse transcription-PCR analysis that nonhepatic cancer cell lines constitutively express fVII mRNA and that endogenously synthesized fVIIa triggers coagulation activation on these cells. fVIIa expression in cancer cells is inducible under hypoxic conditions and hypoxia-inducible factor-2 alpha bound the promoter region of the FVII gene in chromatin immunoprecipitation analyses. Constitutive fVII expression in an ovarian cancer cell line enhanced both migration and invasion. Enhanced motility was blocked by anti-TF antibodies, factor Xa inhibition, and anti-protease-activated receptor-1 antibody treatment, confirming that TF/fVIIa stimulated migration by triggering cell signaling. This study shows that ectopic synthesis of fVII by cancer cells is sufficient to support proinvasive factor Xa-mediated protease-activated receptor-1 signaling and that this pathway is inducible under hypoxia.
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PMID:Activation of cancer cell migration and invasion by ectopic synthesis of coagulation factor VII. 1701

Accelerated fibrinolysis associated with liver disease can be demonstrated by various tests that are either nonspecific in liver disease or that demonstrate only an extrinsic pathway. In the present study we used a new method to assess the global fibrinolytic capacity (GFC) of both the intrinsic and extrinsic pathways in patients with chronic liver disease. Forty patients with the diagnosis of chronic liver disease were included in the study. Seventeen age-matched and gender-matched healthy control individuals were enrolled as a control group. The GFC was studied with semiquantitative macrolatex agglutination. The study population consisted of 40 patients with chronic liver disease (group 1, patients with chronic hepatitis; group 2, patients with cirrhosis; group 3, patients with hepatocellular carcinoma), mean age 53.3 +/- 13 years, and a control group (group 4) consisting of 17 healthy individuals (mean age 55 +/- 12.2 years). The GFC was significantly higher in patients than in control individuals (13.8 +/- 9 microg/ml, 13.6 +/- 11 microg/ml, 14.1 +/- 14 microg/ml, 1.9 +/- 2.2 microg/ml, respectively; P < 0.05). There was no difference between the patient groups (P > 0.05). There was a significant positive relationship between the GFC and the prothrombin time and activated partial thromboplastin time values (P < 0.05). A negative correlation was also observed between the GFC and thrombocyte counts (P < 0.05). In conclusion, our results suggest that patients with chronic liver disease have hyperfibrinolysis, as reflected by the increased GFC. Elucidation of the GFC in chronic liver disease can reflect the net fibrinolytic capacity of those patients who are prone to hyperfibrinolysis resulting in bleeding tendencies and hemorrhages.
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PMID:Hemostasis and global fibrinolytic capacity in chronic liver disease. 1789 Sep 49


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