scholarly journals Glucocorticoid and developmental regulation of amylase mRNAs in mouse liver cells.

1988 ◽  
Vol 8 (9) ◽  
pp. 3857-3863 ◽  
Author(s):  
L C Samuelson ◽  
P R Keller ◽  
G J Darlington ◽  
M H Meisler
Keyword(s):  
Cell Line ◽  
Mouse Liver ◽  
Hepatoma Cell ◽  
Hepatoma Cells ◽  
Liver Cells ◽  
Mouse Serum ◽  
Hepatoma Cell Line ◽  
Glucocorticoid Treatment ◽  
Mouse Tissues

We characterized alpha-amylase expression in the hepatoma cell line Hepa 1-6 and in normal mouse liver. Both Amy-1 and Amy-2 were expressed in Hepa 1-6 and were regulated by glucocorticoids. Transcription in the hepatoma cells was initiated at the same start sites as in mouse tissues. Glucocorticoid treatment increased the abundance of Amy-1 and Amy-2 transcripts by 10 to 20-fold. This increase was detected within 4 h and was maximal by 24 h. The pattern of amylase expression in this hepatoma cell line accurately reflects amylase expression in the liver in vivo. During liver development, we observed a large increase in the abundance of Amy-1 transcripts just before birth, at a time when circulating glucocorticoids are also elevated. Adult mouse liver expressed Amy-1 and Amy-2 at levels comparable to those of fully induced hepatoma cells. Liver is thus a likely source of both amylase isozymes in mouse serum. These studies demonstrate that Amy-2 expression is not limited to the pancreas but also occurs at a low level in liver cells.

Glucocorticoid and developmental regulation of amylase mRNAs in mouse liver cells

1988 ◽  
Vol 8 (9) ◽  
pp. 3857-3863
Author(s):  
L C Samuelson ◽  
P R Keller ◽  
G J Darlington ◽  
M H Meisler
Keyword(s):  
Cell Line ◽  
Mouse Liver ◽  
Hepatoma Cell ◽  
Hepatoma Cells ◽  
Liver Cells ◽  
Mouse Serum ◽  
Hepatoma Cell Line ◽  
Glucocorticoid Treatment ◽  
Mouse Tissues

We characterized alpha-amylase expression in the hepatoma cell line Hepa 1-6 and in normal mouse liver. Both Amy-1 and Amy-2 were expressed in Hepa 1-6 and were regulated by glucocorticoids. Transcription in the hepatoma cells was initiated at the same start sites as in mouse tissues. Glucocorticoid treatment increased the abundance of Amy-1 and Amy-2 transcripts by 10 to 20-fold. This increase was detected within 4 h and was maximal by 24 h. The pattern of amylase expression in this hepatoma cell line accurately reflects amylase expression in the liver in vivo. During liver development, we observed a large increase in the abundance of Amy-1 transcripts just before birth, at a time when circulating glucocorticoids are also elevated. Adult mouse liver expressed Amy-1 and Amy-2 at levels comparable to those of fully induced hepatoma cells. Liver is thus a likely source of both amylase isozymes in mouse serum. These studies demonstrate that Amy-2 expression is not limited to the pancreas but also occurs at a low level in liver cells.

Activation of the silent endogenous cholesterol-7-alpha-hydroxylase gene in rat hepatoma cells: a new complementation group having resistance to 25-hydroxycholesterol

1991 ◽  
Vol 11 (4) ◽  
pp. 2049-2056
Author(s):  
J K Leighton ◽  
S Dueland ◽  
M S Straka ◽  
J Trawick ◽  
R A Davis
Keyword(s):  
Cell Line ◽  
Cholesterol Biosynthesis ◽  
Hepatoma Cell ◽  
Regulatory Elements ◽  
Hepatoma Cells ◽  
Complementation Group ◽  
Hepatoma Cell Line ◽  
Cytotoxic Action ◽  
Hydroxylase Activity ◽  
Rat Hepatoma

The oxysterol 25-hydroxycholesterol acts both as a regulatory sterol determining the expression of genes governed by sterol regulatory elements and as a substrate for 7-alpha-hydroxylase, the first and rate-limiting enzyme in the bile acid synthetic pathway. Most wild-type nonhepatic cells are killed by the cytotoxic action of 25-hydroxycholesterol. In contrast, liver cells, which express 7-alpha-hydroxylase activity, are resistant to killing by 25-hydroxycholesterol. We examined the possibility that selection for resistance to 25-hydroxycholesterol might lead to the derivation of a cell line expressing 7-alpha-hydroxylase. A rat hepatoma cell line (7-alpha-hydroxylase minus) was transfected with human DNA and screened for resistance to 25-hydroxycholesterol. Although parental hepatoma cells were all killed within a week, a 25-hydroxycholesterol-resistant cell line (L35 cells) which showed stable expression of 7-alpha-hydroxylase activity and mRNA was obtained. These cells exhibited normal inhibition of cholesterol biosynthesis by 25-hydroxycholesterol. Blocking 7-alpha-hydroxylase activity with ketoconazole also blocked the resistance of L35 cells to 25-hydroxycholesterol. Isolation of microsomes from these cells showed levels of 7-alpha-hydroxylase activity (22.9 pmol/min/mg of protein) that were comparable to the activity (33.2 pmol/min/mg) of microsomes isolated from the livers of rats killed during the high point of the diurnal cycle. Parental cells had no detectable activity. These data show a new complementation group for 25-hydroxycholesterol resistance: expression of 7-alpha-hydroxylase. Dexamethasone increased both the activity and the cellular content of mRNA coding for 7-alpha-hydroxylase. Since dactinomycin blocked the ability of dexamethasone to induce mRNA, active transcription is required. Southern analysis of genomic DNA showed that L35 cells contain the rat (endogenous) gene but not the human gene. Furthermore, the RNA expressed by L35 cells is similar in size to rat RNA and is distinct from the human form of 7-alpha-hydroxylase. The combined data indicate that L35 cells are resistant to 25-hydroxycholesterol because they express 7-alpha-hydroxylase. The mechanism responsible involves activation of the endogenous (silent) gene of the parental rat hepatoma cell.

scholarly journals Evidence for trans regulation of apoptosis in intertypic somatic cell hybrids.

1994 ◽  
Vol 14 (9) ◽  
pp. 6125-6134 ◽  
Author(s):  
H Gourdeau ◽  
P R Walker
Keyword(s):  
Cell Death ◽  
Somatic Cell ◽  
Cell Line ◽  
Hepatoma Cell ◽  
Hepatoma Cell Line ◽  
Suspension Cells ◽  
Glucocorticoid Treatment ◽  
Cell Hybrids ◽  
Genetic Components ◽  
Cell Death Pathway

The genetic components required for glucocorticoid induction of apoptosis were studied by using somatic cell hybridization. Intertypic whole-cell hybrids were generated by crossing the glucocorticoid-resistant rat liver cell line Fado-2 with the glucocorticoid-sensitive mouse thymoma cell line BW5147.3. Morphological and biochemical criteria were used to assess sensitivity or resistance to glucocorticoid-induced cell death. Both phenotypes were observed, and all of the hybrids retained a functional glucocorticoid receptor as judged by their abilities to induce the metallothionein gene in response to dexamethasone (Dex). Sensitivity to apoptosis did not correlate with morphological phenotype in that not all suspension cells were sensitive. The effect of glucocorticoids on the expression of apoptosis-linked genes was analyzed in a subset of Dex-sensitive and Dex-resistant hybrids. p53 and c-myc mRNAs were present in parental cells as well as sensitive and resistant hybrid cells, and their levels were not affected by glucocorticoid treatment. bcl-2 expression was restricted to the thymoma cell line and was also not affected by glucocorticoids. We did not detect any bcl-2 mRNA in the hepatoma cell line and the hybrids, suggesting that, as with most tissue-specific genes, bcl-2 is regulated in trans. Furthermore, while the majority of hybrids analyzed retained a full complement of mouse chromosomes, sensitive hybrids were missing some rat chromosomes (preferentially chromosomes 16 and 19), indicating that apoptosis is subject to trans repression. Resistant cells thus appear to repress the activity or synthesis of a nuclear factor that interacts with a glucocorticoid-dependent gene(s) to activate the cell death pathway.

Non-genotoxic hepatocarcinogenesis in vitro: the FaO hepatoma line responds to peroxisome proliferators and retains the ability to undergo apoptosis

1993 ◽  
Vol 104 (2) ◽  
pp. 307-315 ◽  
Author(s):  
A.C. Bayly ◽  
N.J. French ◽  
C. Dive ◽  
R.A. Roberts
Keyword(s):  
Cell Death ◽  
Cell Line ◽  
Cell Lines ◽  
Hepatoma Cell ◽  
Hepatoma Cell Line ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferators ◽  
Hepatoma Cell Lines

A range of hepatoma cell lines (RH1, HTC, FaO, 7800C1 and MH1C1), has been studied with the aim of establishing an in vitro model to investigate the molecular mechanisms of hepatocarcinogenicity induced by the peroxisome proliferator class of non-genotoxic carcinogens. In view of speculation that peroxisome proliferators suppress hepatocyte apoptosis in vivo, we have placed particular emphasis on evaluating whether hepatoma cell lines retain the ability to undergo apoptotic cell death. Expression of the liver-specific differentiation marker albumin and the peroxisome proliferator-activated receptor (PPAR) was highest in the Reuber hepatoma cell line, FaO. This cell line also demonstrated the most marked response to the peroxisome proliferator nafenopin with a 2.2-fold induction of the microsomal enzyme cytochrome p450IVA1. This response was found to display intercellular heterogeneity by immunocytochemistry. Thus, the FaO cell line maintained characteristics of hepatocytes, both in vivo and in vitro, in terms of expression of constitutive and inducible markers. However, none of the cell lines tested mirrored the hyperplastic response of hepatocytes to nafenopin, since no increase in cell growth kinetics was observed on addition of nafenopin to the growth medium. The mode of cell death in confluent FaO cultures was characterised as apoptosis, by fluorescence microscopy and agarose gel electrophoresis of extracted DNA. Cells detaching from confluent FaO cultures exhibited chromatin condensation and DNA fragmentation patterns characteristic of cels undergoing apoptotic death.Interestingly, no apoptosis was seen in monolayer cells, suggesting that apoptosis in vitro is associated with cell shrinkage and detachment similar to that documented for the liver in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous expression of salivary and pancreatic amylase genes in cultured mouse hepatoma cells

1986 ◽  
Vol 6 (4) ◽  
pp. 969-975
Author(s):  
G J Darlington ◽  
C C Tsai ◽  
L C Samuelson ◽  
D L Gumucio ◽  
M H Meisler
Keyword(s):  
Hepatoma Cell ◽  
Experimental System ◽  
Hepatoma Cells ◽  
Hepatoma Cell Line ◽  
Cell Type ◽  
Specific Expression ◽  
Consensus Sequences ◽  
Mouse Hepatoma ◽  
Amylase Genes

The tissue-specific expression of two types of mouse amylase genes does not overlap in vivo; the Amy-1 locus is transcribed in the parotid gland and the liver, while expression of Amy-2 is limited to the pancreas. We identified a mouse hepatoma cell line, Hepa 1-6, in which both amylase genes can be simultaneously expressed. Amy-1 is constitutively active in these cells and is inducible by dexamethasone at the level of mRNA. We demonstrated that the liver-specific promoter of Amy-1 is utilized by the dexamethasone-treated hepatoma cells, and that glucocorticoid consensus sequences are present upstream of this promoter. Amy-2 is not detectable constitutively, but can be activated if the cells are cultured in serum-free medium containing dexamethasone. Expression of Amy-2 in a nonpancreatic cell type has not previously been observed. We speculate that induction of Amy-1 and activation of Amy-2 may involve different regulatory mechanisms. Hepa 1-6 cells provide an experimental system for molecular analysis of these events.

scholarly journals Activation of the silent endogenous cholesterol-7-alpha-hydroxylase gene in rat hepatoma cells: a new complementation group having resistance to 25-hydroxycholesterol.

1991 ◽  
Vol 11 (4) ◽  
pp. 2049-2056 ◽  
Author(s):  
J K Leighton ◽  
S Dueland ◽  
M S Straka ◽  
J Trawick ◽  
R A Davis
Keyword(s):  
Cell Line ◽  
Cholesterol Biosynthesis ◽  
Hepatoma Cell ◽  
Regulatory Elements ◽  
Hepatoma Cells ◽  
Complementation Group ◽  
Hepatoma Cell Line ◽  
Cytotoxic Action ◽  
Hydroxylase Activity ◽  
Rat Hepatoma

The oxysterol 25-hydroxycholesterol acts both as a regulatory sterol determining the expression of genes governed by sterol regulatory elements and as a substrate for 7-alpha-hydroxylase, the first and rate-limiting enzyme in the bile acid synthetic pathway. Most wild-type nonhepatic cells are killed by the cytotoxic action of 25-hydroxycholesterol. In contrast, liver cells, which express 7-alpha-hydroxylase activity, are resistant to killing by 25-hydroxycholesterol. We examined the possibility that selection for resistance to 25-hydroxycholesterol might lead to the derivation of a cell line expressing 7-alpha-hydroxylase. A rat hepatoma cell line (7-alpha-hydroxylase minus) was transfected with human DNA and screened for resistance to 25-hydroxycholesterol. Although parental hepatoma cells were all killed within a week, a 25-hydroxycholesterol-resistant cell line (L35 cells) which showed stable expression of 7-alpha-hydroxylase activity and mRNA was obtained. These cells exhibited normal inhibition of cholesterol biosynthesis by 25-hydroxycholesterol. Blocking 7-alpha-hydroxylase activity with ketoconazole also blocked the resistance of L35 cells to 25-hydroxycholesterol. Isolation of microsomes from these cells showed levels of 7-alpha-hydroxylase activity (22.9 pmol/min/mg of protein) that were comparable to the activity (33.2 pmol/min/mg) of microsomes isolated from the livers of rats killed during the high point of the diurnal cycle. Parental cells had no detectable activity. These data show a new complementation group for 25-hydroxycholesterol resistance: expression of 7-alpha-hydroxylase. Dexamethasone increased both the activity and the cellular content of mRNA coding for 7-alpha-hydroxylase. Since dactinomycin blocked the ability of dexamethasone to induce mRNA, active transcription is required. Southern analysis of genomic DNA showed that L35 cells contain the rat (endogenous) gene but not the human gene. Furthermore, the RNA expressed by L35 cells is similar in size to rat RNA and is distinct from the human form of 7-alpha-hydroxylase. The combined data indicate that L35 cells are resistant to 25-hydroxycholesterol because they express 7-alpha-hydroxylase. The mechanism responsible involves activation of the endogenous (silent) gene of the parental rat hepatoma cell.

scholarly journals Development of an interleukin (IL) 6 receptor antagonist that inhibits IL-6-dependent growth of human myeloma cells.

1994 ◽  
Vol 180 (6) ◽  
pp. 2395-2400 ◽  
Author(s):  
F D de Hon ◽  
M Ehlers ◽  
S Rose-John ◽  
S B Ebeling ◽  
H K Bos ◽  
...  
Keyword(s):  
Cell Line ◽  
Inflammatory Diseases ◽  
Hepatoma Cell ◽  
Myeloma Cell ◽  
Oncostatin M ◽  
Mutant Protein ◽  
Hepatoma Cell Line ◽  
Wild Type ◽  
Human Hepatoma Cell

The pleiotropic cytokine interleukin 6 (IL-6) plays a role in the pathogenesis of various diseases, such as multiple myeloma, autoimmune and inflammatory diseases and osteoporosis. Therefore, specific inhibitors of IL-6 may have clinical applications. We previously succeeded in developing receptor antagonists of IL-6 that antagonized wild-type IL-6 activity on the human Epstein-Barr virus (EBV)-transformed B cell line CESS and the human hepatoma cell line HepG2. However, these proteins still had agonistic activity on the human myeloma cell line XG-1. We here report the construction of a novel mutant protein of IL-6 in which two different mutations are combined that individually disrupt the association of the IL-6/IL-6 receptor (R) alpha complex with the signaltransducing "beta" chain, gp130, but leave the binding of IL-6 to IL-6R alpha intact. The resulting mutant protein (with substitutions of residues Gln160 to Glu, Thr163 to Pro, and replacement of human residues Lys42-Ala57 with the corresponding residues of mouse IL-6) was inactive on XG-1 cells and weakly antagonized wild-type IL-6 activity on these cells. By introducing two additional substitutions (Phe171Leu, Ser177Arg), the affinity of the mutant protein for IL-6R alpha was increased fivefold, rendering it capable of completely inhibiting wild-type IL-6 activity on XG-1 cells. Moreover, this mutant also antagonized the activity of IL-6, but not that of leukemia inhibitory factor, oncostatin M, or GM-CSF on the human erythroleukemia cell line TF-1, demonstrating its specificity for IL-6. These data demonstrate the feasibility of developing specific IL-6R antagonists. The availability of such antagonists may offer an approach to specifically inhibit IL-6 activity in vivo.

scholarly journals In Vivo and In Vitro Effect of a Nutrient Mixture on Human Hepatoma Cell Line SK‐Hep‐1

2007 ◽  
Vol 21 (6) ◽  
Author(s):  
M. Waheed Roomi ◽  
Vadim Ivanov ◽  
Aleksandra Niedzwiecki ◽  
Matthias Rath
Keyword(s):  
Cell Line ◽  
Hepatoma Cell ◽  
Hepatoma Cell Line ◽  
Human Hepatoma ◽  
Human Hepatoma Cell ◽  
Human Hepatoma Cell Line ◽  
Vitro Effect

scholarly journals Suitability of hepatocyte cell lines HepG2, AML12 and THLE-2 for investigation of insulin signalling and hepatokine gene expression

Open Biology ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 180147 ◽  
Author(s):  
Stephanie Sefried ◽  
Hans-Ulrich Häring ◽  
Cora Weigert ◽  
Sabine S. Eckstein
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Hepg2 Cells ◽  
Insulin Signalling ◽  
Hepatoma Cell ◽  
Human Cell Line ◽  
Hepatoma Cell Line ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Immortal hepatocyte cell lines are widely used to elucidate insulin-dependent signalling pathways and regulation of hepatic metabolism, although the often tumorigenic origin might not represent the metabolic state of healthy hepatocytes. We aimed to investigate if murine cell line AML12 and human cell line THLE-2, which are derived from healthy liver cells, are comparable to hepatoma cell line HepG2 for studying acute insulin signalling and expression of gluconeogenic enzymes and hepatokines. Insulin responsiveness of AML12 and THLE-2 cells was impaired when cells were cultured in the recommended growth medium, but comparable with HepG2 cells by using insulin-deficient medium. THLE-2 cells showed low abundance of insulin receptor, while protein levels in HepG2 and AML12 were comparable. AML12 and THLE-2 cells showed only low or non-detectable transcript levels of G6PC and PCK1 . Expression of ANGPTL4 was regulated similarly in HepG2 and AML12 cells upon peroxisome proliferator-activated receptor δ activation but only HepG2 cells resemble the in vivo regulation of hepatic ANGPTL4 by cAMP. Composition of the culture medium and protein expression levels of key signalling proteins should be considered when AML12 and THLE-2 are used to study insulin signalling. With regard to gluconeogenesis and hepatokine expression, HepG2 cells appear to be closer to the in vivo situation despite the tumorigenic origin.

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