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)

While the effects of insulin, dexamethasone and cytokines on alpha 1-acid glycoprotein gene expression have been investigated in various hepatoma cell lines, the individual and combined effects of these components on the expression of this gene have been rarely studied in cultured normal rat hepatocytes. In this cell model, we have shown that mRNA levels of alpha 1-acid glycoprotein were not decreased at least during the first 24 h of culture under basal conditions. During these short-term cultures, the expression of alpha 1-acid glycoprotein in normal hepatocytes showed a high degree of responsiveness to dexamethasone alone (20-fold increase) and to dexamethasone associated with various cytokines (interleukin-1 beta, interleukin-6 and tumor necrosis factor alpha) with a 40 to 100-fold increase depending on the cytokine. Insulin alone did not modify alpha 1-acid glycoprotein mRNA; however, this hormone exerted a positive effect (about 50% increase) in the presence of dexamethasone or dexamethasone with cytokines. These results indicate that the regulation of alpha 1-acid glycoprotein in cultured normal rat hepatocytes presents major differences when compared to reported observations in rat hepatoma cell lines.
 ...
PMID:Effects of insulin, dexamethasone and cytokines on alpha 1-acid glycoprotein gene expression in primary cultures of normal rat hepatocytes. 872 21

The early stage of the state in which coagulation or fibrinolytic pathway is activated has been difficult to estimate. It has become possible to detect disseminated intravascular coagulation (DIC) at an early stage due to the development of highly sensitive methods which quantitate so called "molecular markers". Herein, to evaluate the clinical usefulness of plasmin-alpha 2-plasmin inhibitor complex (PIC) and tissue factor activity in plasma were examined. The first time, monitoring the plasma levels of PIC might be useful for the diagnosis of a pre-DIC condition and for effective control of therapy. We believed that combination assay for both PIC and D dimer will be adequate to differentiate whether the hemostatic abnormalities are induced mainly by DIC or hepatic insufficiency. Recently, new clinical usefulness of PIC has been reported. The PIC/thrombin-antithrombin III complex ratio was lower in patients with poor prognosis than in those with good prognosis, and it was also lower in those with organ failure than in those without it. The tissue factor is a major activator of the coagulation cascade and may play a role in initiating thrombosis. A simple chromogenic substrate assay for the quantitation of tissue factor activity in plasma samples was developed. Abnormally high levels were found in 80% of the patients with DIC, predominantly in patients with non-hematological solid tumors and acute leukemia. Serial determinations of plasma tissue factor demonstrated that plasma tissue factor changes immediately with the course of DIC. Plasma tissue factor did not correlate with hemostatic markers of DIC such as thrombin-antithrombin III complex, PIC, FDP D-dimer. Tissue factor activity correlated well with membrane anchoring region of tissue factor protein levels. Tissue factor activity correlate with tumor necrosis factor alpha levels in patients with non-hematological solid tumors without hepatocellular carcinoma. These findings suggest that the plasma tissue factor is potentially valuable for monitoring the progress of DIC in a limited population of patients.
 ...
PMID:[Clinical usefulness of the measurements of plasmin-alpha 2-plasmin inhibitor complex and plasma tissue factor activity in patients with disseminated intravascular coagulation]. 881 61

Met and ron proto-oncogenes encode the cell surface receptors for hepatocyte growth factor (HGF) and hepatocyte growth factor-like (HLP) protein, respectively, and induce mitogenesis, motogenesis, morphogenesis, and metastatic activity in various cell types. Overexpression of met in human carcinoma has been reported by several groups including ours; however, the mechanisms that control met gene expression are thus far unclear. The present study focuses on the expression and regulation of the Met and Ron receptors in human hepatocellular carcinoma (HCC). We report here that abnormal expression of met and ron proteins occurs in some cases of human HCC. Using several HCC cell lines as a model system, we show that HGF, as well as other cytokines, such as epidermal growth factor (EGF), interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha), induce met and ron expression. Using several chimeric constructs consisting of various lengths of the met promoter region fused to the reporter gene of chloramphenicol acetyl transferase (CAT), and by performing transient transfection of these constructs into HepG2 cells, we show that induction of met gene expression by HGF and other cytokines is, at least in part, through up-regulation of met gene promoter activity. The DNA region conferring responsiveness to cytokine induction was located within 0.2 kb of the met core promoter. Interestingly, EGF did not stimulate met promoter activity in any of the met-CAT chimeric constructs. These results provide evidence that met and ron are modulated in the liver by a similar cytokine network. In the case of met expression, the 0.2-kb region in the met gene promoter may play an important role in mediating its gene induction in response to HGF and other cytokines. Our results also suggest that unregulated expression of met and ron may be associated with pathological conditions, such as HCC, in the liver.
 ...
PMID:Co-expression and regulation of Met and Ron proto-oncogenes in human hepatocellular carcinoma tissues and cell lines. 921 52

Persistent infection with hepatitis B virus (HBV) is a leading cause of human liver disease and is strongly associated with hepatocellular carcinoma, one of the most prevalent forms of human cancer. Apoptosis (programmed cell death) is an important mediator of chronic liver disease caused by HBV infection. It is demonstrated that the HBV HBx protein acutely sensitizes cells to apoptotic killing when expressed during viral replication in cultured cells and in transfected cells independently of other HBV genes. Cells that were resistant to apoptotic killing by high doses of tumor necrosis factor alpha (TNFalpha), a cytokine associated with liver damage during HBV infection, were made sensitive to very low doses of TNFalpha by HBx. HBx induced apoptosis by prolonged stimulation of N-Myc and the stress-mediated mitogen-activated-protein kinase kinase 1 (MEKK1) pathway but not by up-regulating TNF receptors. Cell killing was blocked by inhibiting HBx stimulation of N-Myc or mitogen-activated-protein kinase kinase 1 using dominant-interfering forms or by retargeting HBx from the cytoplasm to the nucleus, which prevents HBx activation of cytoplasmic signal transduction cascades. Treatment of cells with a mitogenic growth factor produced by many virus-induced tumors impaired induction of apoptosis by HBx and TNFalpha. These results indicate that HBx might be involved in HBV pathogenesis (liver disease) during virus infection and that enhanced apoptotic killing by HBx and TNFalpha might select for neoplastic hepatocytes that survive by synthesizing mitogenic growth factors.
 ...
PMID:Hepatitis B virus HBx protein sensitizes cells to apoptotic killing by tumor necrosis factor alpha. 923 48

We examined the antitumor effects of human recombinant tumor necrosis factor alpha (rhTNF-alpha) and its muteins with the N-terminal amino acid sequence altered by point mutations against transplantable Morris hepatoma 5123 in rats. In vivo studies showed antiproliferative activity of the drugs in the dose range tested. For in vivo studies rhTNF-alpha and muteins were administered intratumorly (i.t.). The preparations were given at a dose of 10 microg/rat, once daily for eight days. Although the therapy was significantly effective in inhibiting tumor growth, complete growth inhibition could not be achieved. Nevertheless, there was a significant increase in survival time of tumor-bearing rats.
 ...
PMID:Regression of Morris hepatoma in response to intralesional treatment with tumor necrosis factor muteins. 934 58

We isolated an 18-kilobase (kb) genomic selenoprotein P clone from a human placenta library and cloned, sequenced, and characterized the 5'-flanking region of the human selenoprotein P gene. Sequence analysis revealed an intron between base pairs (bp) -13 and -14 upstream of the ATG codon and another one between bp 534 and 535 of the coding region. The major transcription start site of selenoprotein P in human HepG2 hepatocarcinoma cells was mapped to bp -70 by 5'-rapid amplification of cDNA ends and by primer extension. 1.8 kb of the 5'-flanking sequence were fused to a luciferase reporter gene. They exhibited functional promoter activity in HepG2 hepatocarcinoma and Caco2 colon carcinoma cells in transient transfection experiments. Treatment of transfected HepG2 cells with the cytokines interleukin 1beta, tumor necrosis factor alpha, and interferon gamma repressed promoter activity. Nuclear extracts of interferon gamma-treated cells bound to a signal transducer and activator of transcription response element of the promoter in gel retardation experiments. By transfection of promoter-deletion constructs, a TATA box and a putative SP1 site were identified to be necessary for selenoprotein P transcription. These data indicate that the human selenoprotein P gene contains a strong promoter that is cytokine responsive. Furthermore, selenoprotein P, secreted by the liver, might react as a negative acute phase protein.
 ...
PMID:Cloning and characterization of the human selenoprotein P promoter. Response of selenoprotein P expression to cytokines in liver cells. 936 Oct 18

To explore the mechanisms of immuno-modulatory activities of bleomycin, we investigated interferon gamma (IFN gamma) mRNA expression, tumor necrosis factor alpha (TNF alpha) production, nitric oxide (NO) production and macrophage tumoricidal activities in rats bearing KDH-8 hepatoma cells, which secreted a large amount of transforming growth factor beta (TGF beta), and these processes in KDH-8 tumor-bearing rats treated with bleomycin. We found that IFN gamma mRNA expression, TNF alpha production, NO production and macrophage cytotoxic activities were lower in the KDH-8-bearing rats than in normal rats. On the other hand, low-dose bleomycin restored the macrophage cytotoxic activities, NO production, IFN gamma mRNA expression and TNF alpha production in the KDH-8-bearing rats. In vitro experiments showed that KDH-8-derived TGF beta decreased the IFN gamma mRNA expression and TNF alpha production in splenocytes, and NO production in peritoneal macrophages. These results suggest that low-dose bleomycin restored the cytokine production and macrophage tumoricidal activities in the KDH-8-bearing rats by decreasing KDH-8-derived TGF beta.
 ...
PMID:Restoration of macrophage tumoricidal activity by bleomycin correlates with the decreased production of transforming growth factor beta in rats bearing KDH-8 hepatoma cells. 939 Jan 97

The effect of orally administering cabbage juice on tumor necrosis factor alpha (TNF) and interleukin-1 (IL-1) productivity was studied in resident peritoneal macrophages from normal and hepatoma-bearing rats. The productivity of TNF and IL-1 was stimulated by gastric intubation of cabbage juice in the normal state, but not in the hepatoma-bearing state where the production of these cytokines had already been stimulated. From these results, cabbage may contain some effective component(s) that can be absorbed from the gastrointestinal tract to stimulate the production of TNF and IL-1.
 ...
PMID:Stimulation of tumor necrosis factor and interleukin-1 productivity by the oral administration of cabbage juice to rats. 940 76

Expression of the bradykinin B1 receptor gene is up-regulated in vascular smooth muscle cells (VSMCs) in response to a variety of inflammatory stimuli. We isolated the 5'-flanking region of the human bradykinin B1 receptor gene and examined its promoter activity by transient transfection analysis. This region (-2582 to +34) showed promoter activity inducible by lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), and interleukin-1beta (IL-1beta) in VSMCs. Further deletion analysis revealed that constructs containing 111 base pairs of 5'-flanking sequence were sufficient for transcriptional induction. Mutagenesis of a nuclear factor kappaB (NF-kappaB)-like site at -64 to -55 abolished most of the LPS, TNF-alpha, and IL-1beta inducibility, whereas a mutation of a cyclic AMP response element at -50 to -43 markedly reduced the basal promoter activity, and a mutation of the activator protein 1 (AP-1) site at -78 to -72 had minimal effects. Nuclear extracts from LPS, TNF-alpha, and IL-1beta-treated VSMCs, IL-1beta-treated human hepatoma HepG2, and human lung fibroblast IMR-90 cells showed strong inducible binding activity to the NF-kappaB-like site by gel shift assays. These results demonstrated that NF-kappaB-like nuclear factor was involved in the inducible expression of the human bradykinin B1 receptor gene during inflammatory processes.
 ...
PMID:Transcription factor nuclear factor kappaB regulates the inducible expression of the human B1 receptor gene in inflammation. 944 86

The hepatitis B virus-encoded HBx protein coactivates transcription of viral and cellular genes, and it is believed to play an important role in hepatitis B virus-related liver cancer. HBx has been shown to alter the coordinated balance between proliferation and programmed cell death, being able to either induce or block apoptosis. Here, we demonstrate for the first time that the HBx is a potent caspase 3 inhibitor. Rat fibroblasts (REV2) and hepatoma cells (Hep) synthesizing the HBx protein were resistant to various apoptotic stimuli such as growth factor depletion, tumor necrosis factor alpha, or anti-Fas antibodies administration. In these cells, HBx prevented DNA fragmentation and cell death in the absence of de novo protein synthesis, with a similar efficiency as the competitive caspase 3 substrates inhibitors VAD-FMK and DEVD-FMK. Protein extracts obtained from the HBx positive cells contained a very low caspase activity, and addition of anti-HBx antibody restored the endogenous caspase activity. To obtain a functional map of the anti-caspase activity of HBx, various cell lines were established that synthesized either N-terminally or C-terminally truncated HBx molecules. These gene dissection experiments revealed that the regions required for the anti-caspase activity overlap with the two known transactivation domains of HBx.
 ...
PMID:The hepatitis B virus HBx protein inhibits caspase 3 activity. 983 9


<< Previous 1 2 3 4 5 6 7 8 9 Next >>