scholarly journals Rapid and extensive lethal action of clofibrate on hepatoma cells in vitro

1997 ◽  
Vol 4 (3) ◽  
pp. 224-232 ◽  
Author(s):  
Rosa A Canuto ◽  
Giuliana Muzio ◽  
Marina Maggiora ◽  
Riccardo Autelli ◽  
Giuseppe Barbiero ◽  
...  
Keyword(s):  
Hepatoma Cells ◽  
Lethal Action

scholarly journals Expression of laminin γ 1 cultured hepatocytes involves repeated CTC and GC elements in the LAMC1 promoter

1996 ◽  
Vol 313 (3) ◽  
pp. 745-752 ◽  
Author(s):  
Françoise LEVAVASSEUR ◽  
Jocelyne LIÉTARD ◽  
Kohei OGAWA ◽  
Nathalie THÉRET ◽  
Peter D. BURBELO ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Hepatoma Cell ◽  
Primary Cultures ◽  
Regulatory Elements ◽  
Hepatoma Cells ◽  
Basement Membranes ◽  
Major Protein ◽  
Cultured Hepatocytes

Laminin γ1 chain is present in all basement membranes and is expressed at high levels in various diseases, such as hepatic fibrosis. We have identified cis- and trans-acting elements involved in the regulation of this gene in normal rat liver, as well as in hepatocyte primary cultures and hepatoma cell lines. Northern-blot analyses showed that laminin γ1 mRNA was barely detectable in freshly isolated hepatocytes and expressed at high levels in hepatocyte primary cultures, as early as 4 h after liver dissociation. Actinomycin D and cycloheximide treatment in vivo and in vitro indicated that laminin γ1 overexpression in cultured hepatocytes was under the control of transcriptional mechanisms. Transfection of deletion mutants of the 5´ flanking region of murine LAMC1 gene in hepatoma cells that constitutively express laminin γ1 indicated that regulatory elements were located between -594 bp and -94 bp. This segment included GC- and CTC-containing motifs. Gel-shift analyses showed that two complexes were resolved with different affinity for the CTC sequence depending on the location of the GC box. The pattern of complex formation with nuclear factors from freshly isolated and cultured hepatocytes was different from that obtained with total liver and similar to that with hepatoma cells. Southwestern analysis indicated that several polypeptides bound the CTC-rich sequence. Affinity chromatography demonstrated that a Mr 60000 polypeptide was a major protein binding to the CTC motif. This polypeptide is probably involved in the transcriptional activation of various proto-oncogenes and extracellular matrix genes that are expressed at high levels in both hepatoma cells and early hepatocyte cultures.

scholarly journals Estrogen Up-Regulates Hepatic Expression of Suppressors of Cytokine Signaling-2 and -3 in Vivo and in Vitro

Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5525-5531 ◽  
Author(s):  
Gary M. Leong ◽  
Sofia Moverare ◽  
Jesena Brce ◽  
Nathan Doyle ◽  
Klara Sjögren ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Hepatoma Cells ◽  
Cytokine Signaling ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Wild Type ◽  
Hepatic Expression ◽  
Suppressors Of Cytokine Signaling

Abstract Suppressors of cytokine signaling (SOCS) are important negative regulators of cytokine action. We recently reported that estrogen stimulates SOCS-2 expression and inhibits GH signaling in kidney cells. The effects of estrogen on SOCS expression in other tissues are unclear. The aim of this study was to investigate in vivo and in vitro whether estrogen affected SOCS expression in the liver, a major target organ of GH. The in vivo hepatic effects of estrogen on ovariectomized mice lacking estrogen receptor (ER)-α, ERβ, or both and their wild-type littermates were examined by DNA microarray analysis. In vitro, the effects of estrogen on SOCS expression in human hepatoma cells were examined by reverse transcription quantitative PCR. Long-term (3 wk) estrogen treatment induced a 2- to 3-fold increase in hepatic expression of SOCS-2 and -3 in wild-type and ERβ knockout mice but not in those lacking ERα or both ER subtypes. Short-term treatment (at 24 h) increased the mRNA level of SOCS-3 but not SOCS-2. In cultured hepatoma cells, estrogen increased SOCS-2 and -3 mRNA levels by 2-fold in a time- and dose-dependent manner (P < 0.05). Estrogen induced murine SOCS-3 promoter activity by 2-fold (P < 0.05) in constructs containing a region between nucleotides −1862 and −855. Moreover, estrogen and GH had additive effects on the SOCS-3 promoter activity. In summary, estrogen, via ERα, up-regulated hepatic expression of SOCS-2 and -3, probably through transcriptional activation. This indicates a novel mechanism of estrogen regulation of cytokine action.

Anti-tumoral efficiacy of four different histone deacetylase inhibitors on hepatoma cells in vitro

2003 ◽  
Vol 38 ◽  
pp. 95
Author(s):  
M. Ganslmayer ◽  
C. Herold ◽  
M. Ocker ◽  
S. Zopf ◽  
S. Kareth ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Histone Deacetylase Inhibitors ◽  
Hepatoma Cells

Differential sensitivity of AS-30D rat hepatoma cells and normal hepatocytes to anoxic cell damage

1992 ◽  
Vol 262 (6) ◽  
pp. C1384-C1387 ◽  
Author(s):  
C. E. Kobryn ◽  
G. Fiskum
Keyword(s):  
Tumor Cells ◽  
Cell Damage ◽  
Metabolic Stress ◽  
Metastatic Potential ◽  
Cell Types ◽  
Hepatoma Cells ◽  
Differential Sensitivity ◽  
Trypan Blue Exclusion ◽  
Lactate Dehydrogenase Release

A substantial fraction of cells present within hard tumors experience extremely hypoxic and hypoglycemic conditions that can lead to phenotypic alterations such as increased metastatic potential and chemotherapeutic drug resistance. Little is known regarding the influence of anoxic aglycemia on tumor cell energy metabolism and viability, and no direct comparisons have been made between the effects of this form of metabolic stress on tumor cells and their tissue of origin. In this study, the effects of in vitro aglycemic incubation under N2 (with or without iodoacetate) on trypan blue exclusion, lactate dehydrogenase release, cell surface blebbing, ATP levels, and mitochondrial respiratory capacity of rat AS-30D ascites hepatoma cells and normal hepatocytes were measured. Under anoxic-aglycemic conditions, the period of incubation during which 50% viability was lost was 2 h for hepatocytes and 6-8 h for AS-30D cells. In contrast, the rate of anoxia-induced loss of ATP was comparable for the two cell types, and mitochondrial damage was actually accelerated in the tumor cells. These findings suggest that tumor cells are more resistant to anoxic cell death because of their greater ability to withstand deenergization and subcellular injury.

scholarly journals VP22-mediated intercellular transport of p53 in hepatoma cells in vitro and in vivo

2002 ◽  
Vol 9 (6) ◽  
pp. 489-496 ◽  
Author(s):  
Lars Zender ◽  
Florian Kühnel ◽  
Reiner Köck ◽  
Michael Manns ◽  
Stefan Kubicka
Keyword(s):  
Hepatoma Cells ◽  
Intercellular Transport

scholarly journals Properties of phosphoenolpyruvate carboxykinase (guanosine triphosphate) synthesized in hepatoma cells in the presence of amino acid analogues

1975 ◽  
Vol 146 (3) ◽  
pp. 585-593 ◽  
Author(s):  
S E Knowles ◽  
J M Gunn ◽  
L Reshef ◽  
R W Hanson ◽  
F J Ballard
Keyword(s):  
Amino Acid ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Hepatoma Cells ◽  
Dibutyryl Cyclic Amp ◽  
Enzyme Degradation ◽  
Amino Acid Analogues ◽  
Enzyme Molecules ◽  
Natural Amino Acids

1. Phosphoenolpyruvate carboxykinase (GTP) was induced by a combination of dibutyryl cyclic AMP, theophyline and dexamethasone in Reuber H35 hepatoma cells under conditions where an amino acid in the medium was replaced by an appropriate analogue. 2. With canavanine replacing arginine or with 5-fluorotryptophan or 6-fluorotryptophan replacing tryptophan the induced enzyme had a lower catalytic activity-relative to antibody reactivity. 3. These aberrant enzyme molecules were heat-labile in vitro. 4. Measurements of enzyme degradation in vivo indicated that the canavanine-containing enzyme and the 6-fluorotryptophan-containing enzyme were degraded more rapidly than the enzyme containing all natural amino acids.

Adenosine nucleotides in bile

1996 ◽  
Vol 270 (2) ◽  
pp. G246-G252 ◽  
Author(s):  
R. S. Chari ◽  
S. M. Schutz ◽  
J. E. Haebig ◽  
G. H. Shimokura ◽  
P. B. Cotton ◽  
...  
Keyword(s):  
Purinergic Receptors ◽  
Purinergic Receptor ◽  
Receptor Activation ◽  
Hepatoma Cells ◽  
Human Bile ◽  
Nucleotide Release ◽  
Cholangiocarcinoma Cell ◽  
Adenosine Nucleotides ◽  
Vitro Model

Activation of purinergic receptors by ATP stimulates Cl- efflux in biliary epithelial cells. To determine whether purinergic agonists are present under physiological conditions, we have assayed mammalian bile for nucleotides and assessed whether hepatoma and cholangiocarcinoma cell lines are capable of nucleotide release. Bile samples were collected from human, rat, and pig donors and assayed for nucleotide concentrations by luminometry. ATP, ADP, and AMP were present in bile from each species, and the average total nucleotide concentration in human bile was 5.21 +/- 0.91 microM (n = 16). In an in vitro model of HTC rat hepatoma cells or Mz-ChA-1 cholangiocarcinoma cells on a superfused column, nucleotides were present in the effluent from each cell type. Addition of alpha, beta-methyleneadenosine 5'-diphosphate (50 microM) to inhibit 5'-nucleotidase activity increased AMP concentrations two- to threefold. Exposure to forskolin (100 microM) or ionomycin (2 microM) stimulated nucleotide release from cholangiocarcinoma but not hepatoma cells. These studies indicate that adenosine nucleotides are present in bile in concentrations sufficient to activate purinergic receptors. Purinergic receptor activation by local nucleotide release might constitute an autocrine and/or paracrine mechanism for modulation of biliary secretion.

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