The glucocorticoid domain: Steroid-mediated changes in the rate of synthesis of rat hepatoma proteins

Ivarie, Robert; O’Farrell, Patrick H.

doi:10.1016/0092-8674(78)90136-8

Cited by 220 publications

(67 citation statements)

References 22 publications

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“…Consistency of the induction pattern was very good in our hands. We did not find such an extensive variation in relative spot intensities as had been reported for HTC (Morris rat hepatoma HTC cell line) cells [12] probably because of two reasons: (a) cell densities were strictly controlled, so that one major source of variations in protein synthesis could be eliminated; (b) samples were prepared for electrophoresis in the presence of nucleases. This method was shown to reduce variability considerably among preparations [I I].…”

Section: Resultsmentioning

confidence: 84%

“…2B spots 15, 16) were found on the electrophoretogram of clone 2 cells, which were not detectable in Faza 967 ( Fig.2A) and H56 cells. Four spots were much more intense in Faza 967 than in the clone 2 electrophoretogram (spots 8,11,12,14), three of these (spots 11,12,14) were not seen in the case of clone 2 at all. It is interesting to note that spot 11 could not be detected in H56 cells either (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The glucocorticoid domain of these cells had been partially defined previously, by direct measurement of specific glucocorticoid effects [12]. The measure of this domain (i.e.…”

Section: Resultsmentioning

confidence: 99%

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Protein synthesis in differentiated and dedifferentiated hepatoma cell lines

Bösze¹,

Arányi²,

Venetianer³

1983

European Journal of Biochemistry

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The pattern of protein synthesis in hepatoma cell clones was analysed by two-dimensional separation of [3 5S]methionine-iabelled proteins. The clones were derived from the differentiated Reuber H 35 hepatoma and showed differences in the expression of a number of liver-specific functions and the resistance to the growthinhibitory effect of glucocorticoids.Five protein spots were observed in the extracts of the differentiated Faza 967 cells that were absent from the electrophoretogram of the dedifferentiated H56 cells. This clone, on the other hand, displayed six spots absent from Faza 967 cells. The growth of both Faza 967 and H56 cells was strongly inhibited by 1 pM dexamethasone.The dexamethasone-resistant clone 2, a dedifferentiated derivative of Faza 967 cells, synthesized two polypeptides that were not present in Faza 967 or H 56 cells and produced four polypeptides at a lower level than Faza 967 cells. The examination of the short-term effect of dexamethasone on protein synthesis in Faza 967 cells revealed nine induced and one repressed protein spots, which appeared to be in good agreement with earlier published data. It is concluded that dedifferentiation, although bringing about marked changes in certain liver-specific functions, such as enzyme activities or protein secretion, affects only a relatively small fraction of the genes expressed.Hormones play an essential role in gene regulation in multicellular organisms by eliciting specific responses from target cells. It is well known that glucocorticoid hormones have multiple effects in the development and maintenance of the differentiated state of cells [l]. Different cell lines have different phenotypes with respect to their hormone responsiveness. Hepatoma cells express a wide range of liverspecific functions, some of which are under glucocorticoid regulation. Cell lines derived from Reuber H35 rat hepatoma [2,3] express numerous functions of the hepatocytes of the adult liver (e.g. production and secretion of serum albumin, basal activity and inducibility of tyrosine aminotransferase and alanine aminotransferase by glucocorticoids, the liverspecific isozymes of aldolase and alcohol dehydrogenase and the activity of gluconeogenetic enzymes fructose-I ,6-diphosphatase and phosphoenolpyruvate carboxykinase). The hepatoma cells expressing all the above functions will be termed 'well differentiated' hepatomas, while the dedifferentiated ones fail to express the whole group of differentiated functions, and the partially dedifferentiated ones express only some of them [4 -61. The growth of the well-differentiated (Faza 967) and the spontaneously dedifferentiated variants (H56) of the Reuber H35 hepatomas are inhibited by glucocorticoids. We isolated a series of stable dexamethasoneresistant variants from the hormone-sensitive Faza 967 clone [7]. As we reported recently the expression of almost all the differentiated functions decreased or disappeared in these hormone-resistant cell lines during long-term cultivation, in contrast to the sensitive cells, where...

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Section: Resultsmentioning

confidence: 84%

Section: Resultsmentioning

confidence: 99%

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Protein synthesis in differentiated and dedifferentiated hepatoma cell lines

Bösze¹,

Arányi²,

Venetianer³

1983

European Journal of Biochemistry

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“…Indeed, dexamethasone increases the activity of tyrosine aminotransferase mRNA in HTC cells (30). The finding that nucleoside diphosphatase is inhibited by dexamethasone pertains to the question of whether glucocorticoids can repress as well as induce polypeptide synthesis (11). These hormones certainly inhibit several cell functions.…”

Section: Discussionmentioning

confidence: 99%

“…(10). In this system the hormonal response is very specific in that the number of glucocorticoidsensitive gene products is quite limited (11). Only seven proteins are reproducibly induced, including two unidentified membrane proteins.…”

Section: Introductionmentioning

confidence: 99%

Glucocorticoid hormones increase the activity of plasma membrane alkaline phosphodiesterase I in rat hepatoma cells.

Rousseau¹,

Amar-Costesec²,

Verhaegen³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

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In rat hepatoma cells the synthetic glucocorticoid dexamethasone causes a 3-fold increase in the activity of the plasma membrane enzyme alkaline phosphodiesterase I (oligonucleate 5'-nucleotidohydrolase, EC 3.1.4.1). The data are consistent with an induction phenomenon mediated by the glucocorticoid receptor involved in tyrosine aminotransferase induction. The Glucocorticoids modify several properties of cellular plasma membranes. One of the earliest effects of these hormones in lymphoid cells is an inhibition of hexose, nucleoside, and amino acid uptake (1). Glucocorticoid hormones also decrease hexose uptake by fibroblasts (2) and by adipocytes (3). In rat hepatoma tissue culture (HTC) cells, glucocorticoids promote cell adhesiveness and the reappearance of surface antigens present in normal hepatocytes (4). These hormones also inhibit the release of plasminogen activator (5) and the uptake of aminoisobutyric acid (6, 7), and they decrease the number of cell surface microvilli (8). Such modifications of HTC cell membrane functions have been considered as part of a program of glucocorticoid-induced reversal of the transformed phenotype (8). The biochemical reactions underlying these effects have not been elucidated.Glucocorticoid hormones appear to produce many of their physiological effects through a stimulation of the activity of specific enzymes in target cells, most often as a result of an increase in their rate of synthesis (9). This prompted us to examine whether enzymes located in the plasma membrane could be under glucocorticoid control, an effect that might be related to one or more of the phenomena described above. This possibility was investigated in HTC cells wherein the interaction of steroids with intracellular receptors and the ensuing induction of tyrosine aminotransferase (L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) have been extensively studied as a model of glucocorticoid action.(10). In this system the hormonal response is very specific in that the number of glucocorticoidsensitive gene products is quite limited (11). Only seven proteins are reproducibly induced, including two unidentified membrane proteins. We show here that, in HTC cells, glucocorticoid hormones specifically increase the activity of alkaline phosphodiesterase I (oligonucleate 5'-nucleotidohydrolase, EC 3.1. Enzyme Assays. For determination of alkaline phosphodiesterase I, frozen HTC cells were sonicated for 10 sec (Branson Sonifier) in an aqueous solution of Triton X-100 (1 g/liter). Enzyme activity was determined as described by Beaufay et al. (15) by incubating the sample for 10 min at 250C in a mixture containing 0.1 M glycine-NaOH (pH 9.6), 2 mM zinc acetate, and 3 mM p-nitrophenylthymidine 5'-phosphate (from Sigma or Boehringer Mannheim). The reaction rate was constant for at least 20 min and the assay was linear with protein concentration up to 120 ,ug per assay. For determination of tyrosine aminotransferase activity, cells were sonicated as described above in 50 mM potassium phosphate buffer...

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The Human Protein Index

Anderson¹

1981

JAMA

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The glucocorticoid domain: Steroid-mediated changes in the rate of synthesis of rat hepatoma proteins

Cited by 220 publications

References 22 publications

Protein synthesis in differentiated and dedifferentiated hepatoma cell lines

Protein synthesis in differentiated and dedifferentiated hepatoma cell lines

Glucocorticoid hormones increase the activity of plasma membrane alkaline phosphodiesterase I in rat hepatoma cells.

The Human Protein Index

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