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)

A human hepatocellular carcinoma line, HepG2, was found to secrete coagulation Factor V. Factor V activity in HepG2 culture fluid increased nearly linearly during a 20-h time course (5 ng Factor Va/h per 10(6) cells). Thrombin treatment increased Factor V activity in HepG2 culture medium six- to ninefold, indicating that the medium accumulates a mixture of Factors V and Va. To demonstrate de novo synthesis of Factor V, HepG2 cells were incubated in culture medium containing [35S]methionine. Labeled Factor V was immunoprecipitated from the medium and was shown to co-migrate with purified plasma Factor V upon sodium dodecyl sulfate polyacrylamide gel electrophoresis and fluorography. When medium was treated with thrombin before immunoprecipitation and fluorography, the 330,000-Mr [35S]methionine-labeled Factor V was converted to Factor Va. Factor Va coagulant activities from HepG2 cells and human plasma were inhibited in parallel by anti-Factor V antibody, indicating that HepG2 and plasma Factor Va have the same intrinsic activity. If normal hepatocytes synthesize Factor V at the same rate as HepG2 cells, then hepatocyte secretion can account for the total Factor V present in plasma. The production of Factor V by cultured human umbilical vein endothelial cells was also examined. Spent culture medium from endothelial cells contained only Factor Va and the amount was less than 1% of the activity found in medium from HepG2 cells under comparable conditions. The amount of Factor V activity in endothelial cell culture fluid did not change with time in culture.
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PMID:Biosynthesis of coagulation Factor V by a human hepatocellular carcinoma cell line. 620 Apr 98

A 17-year-old male with previously undiagnosed congenital Factor IX deficiency (13%) presented with gastrointestinal bleeding and a hepatic mass. Prolonged thrombin and Reptilase times, which partially corrected with CaCl2 and a discrepancy between thrombin-clottable and immunoreactive plasma fibrinogen, suggested a dysfibrinogenemia. Laparotomy disclosed metastatic hepatoma. Adequate hemostasis was obtained with clotting factor replacement, but wound healing was delayed. Patient fibrinogen purified with 2.1 M glycine migrated normally on immunoelectrophoresis and 7.5% polyacrylamide-SDS gel electrophoresis. However, fibrin monomers prepared from purified patient fibrinogen displayed impaired aggregation at high and low ionic strengths when compared with fibrin monomers from normal and control Factor IX deficient subjects. Aggregation of normal monomers was delayed when mixed 1:1 with patient monomers. Fibrinopeptide release was normal, and total sialic acid content was similar to that of normal and control fibrinogens. Chemotherapy, consisting of 5-FU given via intra-arterial hepatic infusion, was accompanied by significant transient clinical improvement which coincided with correction of thrombin clotting times and fibrin monomer aggregation. Reappearance of fibrinogen dysfunction occurred with clinical deterioration prior to death from metastatic hepatoma and sepsis. This case is the first to corroborate the postulated tumor marker role of dysfibrinogenemia in a patient with hepatoma by documenting a direct relationship with response to chemotherapy.
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PMID:Acquired dysfibrinogenemia in a hemophiliac with hepatoma: resolution of fibrinogen dysfunction following chemotherapy. 626 56

Insulin stimulates the growth and proliferation of a variety of somatic cells in culture, and evidence suggests that insulin is also an important regulator of growth in vivo. In cell culture, insulin interacts synergistically with other hormones and growth factors such as platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), tumor-promoting phorbol esters, and thrombin, to stimulate progression through the cell cycle of cells that have been arrested in G1 by deprivation for serum. In addition, insulin is required by most cells for optimal long term growth in hormone-supplemented serum-free media. In some cells, such as human skin fibroblasts, the growth-promoting effects of insulin appear to be mediated primarily by its low affinity interaction with receptors for insulin-like growth factor I (IGF-I). In other cells, such as hepatocytes, hepatoma cells, adrenocortical tumor cells, mammary carcinoma cells, and F9 embryonal carcinoma cells, insulin appears to stimulate growth by binding to high affinity insulin receptors. The insulin and IGF-I receptor proteins, like the receptor proteins for other growth-promoting hormones such as EGF and PDGF, are closely associated with tyrosine-specific protein kinase activities. The mechanism by which the binding of insulin to its receptor and activation of the receptor-associated tyrosine protein kinase activity control intracellular protein phosphorylation and dephosphorylation reactions, such as the phosphorylation of ribosomal protein S6, is a subject of considerable current interest. The phosphorylation of ribosomal protein S6 may be related mechanistically to the activation by insulin of protein synthesis, and hence the passage of cells through the G1 phase of the cell cycle. Malignant transformation does not generally result in a total loss of the growth requirement of cells for insulin or insulin-like growth factors, although transformation is accompanied in some cases by a qualitative reduction in the insulin/IGF requirement. Abnormalities in insulin production or sensitivity in vivo are accompanied by abnormalities in growth; thus, insulin appears to be an important regulator of growth in vivo. Some of the growth-promoting effects of insulin in vivo may be attributable to direct action of insulin, while other effects may be caused by the regulatory effect of insulin on somatomedin production, and possibly on somatomedin action.
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PMID:Growth-stimulatory actions of insulin in vitro and in vivo. 637 81

The addition of excess sodium citrate to plasma was found to inhibit fibrin polymerisation (clot opacity) from patients with cirrhosis, hepatitis and hepatoma but not from normal controls. Abnormal clot opacity in plasma from patients with liver disease could be partly or completely abolished by removal of citrate ions by dialysis against citrate-free buffer, but not by dialysis against buffer containing citrate. Similar results were observed in plasma freed of calcium ions by treatment with EGTA. Treatment of plasma with neuraminidase largely abolished the inhibitory effect of excess citrate, and the thrombin times and clot opacity of asialofibrinogen were less affected by citrate than native fibrinogen. In addition, the effects of citrate on the clotting of purified, calcium-free fibrinogen from cirrhotic patients correlated with the sialic acid content. It is concluded that binding of citrate ions to fibrinogen renders the molecule acutely more sensitive to elevations in the sialic acid content, and that a simple plasma clot opacity test in the presence of excess citrate may be a useful aid in the differential diagnosis of liver disease. These findings may also explain why defects in fibrin polymerisation observed in plasma are not always reproduced in purified fibrinogen or fibrin monomer preparations.
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PMID:The role of sodium citrate in the dysfibrinogenaemia of liver disease. 672 77

Vertebrate fibrinogen consists of two sets of three nonidentical polypeptides that are synthesized in the liver. The subunits of fibrinogen have been synthesized in a cell-free, membrane-free translation system and compared with (alpha), polypeptides of fibrinogen purified from rat plasma and (b) subunits synthesized and secreted by hepatoma cells grown in culture. Rat hepatoma monolayers were grown with or without tunicamycin to prevent or allow glycosylation of the B beta and gamma subunits, respectively. Sodium dodecyl sulfate polyacrylamide gel analysis indicated that each of the polypeptides translated in vitro from mRNA is larger than its corresponding nonglycosylated fibrinogen chain. The primary translation A alpha, B beta, and gamma chains are larger than their authentic nonglycosylated counterparts by 600, 1100, and 3000 daltons, respectively. Furthermore, the preA alpha and preB beta translation products are thrombin sensitive. These results strongly imply that signal peptides exist on each of the primary translation products of fibrinogen.
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PMID:In vitro synthesis of rat fibrinogen: identification of preA alpha, preB beta, and pre gamma polypeptides. 694 Dec 47

A protein showing lower electrophoretic mobility in acidic urea polyacrylamide gels than did the usual histone H1 subfractions has been detected among the H1 histones extracted from chromatin of a transplantable hamster hepatoma, originally induced by Kirkman and Robbins. It was proved to be a true H1 histone subfraction. It differs from the remaining ones by the total chain length, amino acid composition, and isoelectric point value. It is not a phosphorylated or phosphoribosylated metabolic form of another subfraction. Its proteolytic degradation products (obtained by thrombin and trypsin digestion) closely resembled those obtained from other H1 subfractions. The investigated hepatoma seems to provide an interesting model of neoplastic cells showing a distinct difference in histone composition from the homologous normal tissue.
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PMID:A low-electrophoretic-mobility H1 histone subfraction from Kirkman-Robbins hamster hepatoma. 723 41

A new platelet aggregation inhibitor compound, 5-(2-chlorobenzyl-4,5,6,7-tetrahydrothieno[3,2-C]pyridine hydrochloride (ticlopidine), was examined for its inhibitory effects on blood-borne metastasis using three different rodent tumors (B16 melanoma, Lewis lung carcinoma, and rat ascites hepatoma, AH130). Ticlopidine was administered p.o. to the rodents. It inhibited the aggregation of platelets induced by adenosine diphosphate, thrombin, crude extract of AH130, and viable AH130 and B16 melanoma cells and also resulted in a significant decrease of pulmonary metastasis induced by i.v. injection of B16 melanoma and AH130. Spontaneous pulmonary metastasis of Lewis lung carcinoma was also inhibited by p.o. administration of ticlopidine. This new compound may be a useful agent for inhibiting platelet aggregation caused by various agents and for suppressing hematogenous pulmonary metastasis.
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PMID:Effects of 5-(2-chlorobenzyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridine hydrochloride (Ticlopidine), a platelet aggregation inhibitor, on blood-borne metastasis. 730 88

Thrombomodulin (TM) converts thrombin from procoagulant into anticoagulant protein to activate protein C. Thrombin also plays an important role in the metastatic process of cancer cells. We performed an immunohistochemical and clinicopathological study of TM in 141 cases with resected hepatocellular carcinoma (HCC) measuring less than 6 cm in diameter. Twenty-five specimens (17.73%) stained positive for TM. TM was found in the cytoplasm and surface of cancer cells. The clinicopathological findings according to the positive of TM are examined in HCC. The preoperative plasma TM level of the patients with tissue that stained positive for TM was significantly higher than that of the patients with negative results; for the postoperative TM level, there were no differences between them. In addition, the frequencies of intrahepatic metastasis, tumor thrombus in the portal vein, and capsular infiltration were significantly lower in patients whose tissue stained positive for TM than in patients whose tissue stained negative for TM. The recurrence freedom rate was significantly higher in patients whose tissue stained positive for TM than patients whose tissue stained negative for TM. Thus, TM-producing HCC shows a slow intrahepatic spread. Therefore, these findings suggest that TM may inhibit the adhesion of tumor cells to the portal vein because of anticoagulant activity and thus prevent the spread of intrahepatic metastasis.
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PMID:Thrombomodulin inhibits intrahepatic spread in human hepatocellular carcinoma. 753 12

The blood coagulation and fibrinolysis of 33 patients with compensated liver cirrhosis and 31 patients with hepatocellular carcinoma were examined using several markers, namely thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC), antithrombin-III (AT-III) and prothrombin time, and the relationship between these markers, endotoxemia, and TNF-alpha was examined. These patients had no complications due to hepatic failure, such as infections, encephalopathy, ascites, G-I bleeding and clinical DIC. PIC was not elevated, but TAT tended to be elevated in LC and significantly elevated in HCC. AT-III was decreased in LC and HCC, and the blood endotoxin was partly positive in LC and HCC, but was not correlated with AT-III or PT. The TAT level in the blood-endotoxin-positive patients measured by endospecy methods was higher than that in the negative patients, and was significantly correlated with the blood endotoxin level in the LC and HCC patients (r = 0.57, r = 0.88, p < 0.01). No relationship was observed between TNF-alpha and blood endotoxin. In conclusion, (1) blood coagulability was activated already in compensated LC and HCC, but was not connected with fibrinolysis, (2) the activation of coagulability was closely related with endotoxemia, and (3) TNF-alpha was not correlated with blood endotoxin or TAT.
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PMID:[Blood coagulation and fibrinolysis in relation to endotoxemia in liver cirrhosis and hepatocellular carcinoma]. 756 21

Cultured adult rodent hepatocytes are extensively used as a model system for gene transfer in vitro. In the present study, we examined the influence differentiation status and growth capacity of the hepatocytes on their infectivity in vitro by a retroviral vector. These parameters were initially studied in primary cultures of rat hepatocytes transduced with an ecotropic retroviral vector containing Escherichia coli beta-galactosidase. However, significant differences observed in the infectivity of hepatocytes from 12-day-old and adult rats led us to also examine hepatocytes from a transgenic mouse strain in which the SV40 large T antigen is fused to the regulatory sequences of the human anti-thrombin III gene. The large T antigen is expressed in the liver and these mice develop hepatoma within 7 months. A comparison of infectivity of hepatocytes from normal and transgenic mice of different ages indicated that in contrast to previous reports, hepatocytes which express differentiated functions during the first week of culture can still be efficiently infected by retroviral vectors. Optimal infection was observed between the second and fourth day of culture and does not appear to be due to transient cell dedifferentiation, but is more likely due to transient mitotic activity of mice cells since the role of growth factors seems crucial for infection. The peak of infection did not appear to correspond to transient cell dedifferentiation. We also found differences of infectivity between hepatocytes from normal and transgenic mice of different ages. Such differences are correlated with differences in in vitro BrdU incorporation, which was used to determine the proportion of dividing hepatocytes. These results indicate that the efficiency of infectivity of hepatocytes by recombinant retrovirus is probably related to their normal proliferative potential and not to some dedifferentiated stage. Hence these findings provide a model for efficient gene transfer in differentiated cells and suggest an approach for studies of liver-specific gene regulation and for somatic gene therapy of metabolic diseases as well.
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PMID:Retroviral infection of primary hepatocytes from normal mice and mice transgenic for SV40 large T antigen. 768 Oct 9


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