scholarly journals The effect of bromodeoxyuridine and dibutyryl cyclic AMP on the induction of placental alkaline phosphate in human choriocarcinoma cells

1981 ◽  
Vol 198 (1) ◽  
pp. 29-35 ◽  
Author(s):  
T A Hamilton ◽  
H H Sussman
Keyword(s):  
Alkaline Phosphatase ◽  
Cyclic Amp ◽  
Polyacrylamide Gel Electrophoresis ◽  
Specific Protein ◽  
Placental Alkaline Phosphatase ◽  
Dibutyryl Cyclic Amp ◽  
Specific Enzyme ◽  
Alkaline Phosphate ◽  
Choriocarcinoma Cells ◽  
Human Choriocarcinoma Cells

The effect of 5-bromo-2′-deoxyuridine (BrdUrd) and dibutyryl cyclic AMP (Bt2cAMP) on the expression of the placental isoenzyme of human alkaline phosphatase was examined in BeWo choriocarcinoma cells. By using a combination of specific immunoprecipitation and polyacrylamide-gel electrophoresis of cells labelled either metabolically with [35S]methionine or cell-surface-labelled with 125I, both BrdUrd (5 micrograms/ml) and 1 mM-Bt2cAMP were shown to result in the enhanced accumulation of a specific protein. This protein has immunochemical identity and co-electrophoreses with placental alkaline phosphatase in two-dimensional gels. These results clearly demonstrate that the induction of placental alkaline phosphatase activity in choriocarcinoma cells treated with these agents is a consequence of the accumulation of specific enzyme protein rather than of altered catalytic activity.

scholarly journals Expression of the Germ Cell Alkaline Phosphatase Gene in Human Choriocarcinoma Cells

1989 ◽  
Vol 264 (21) ◽  
pp. 12611-12619
Author(s):  
S Watanabe ◽  
T Watanabe ◽  
W B Li ◽  
B W Soong ◽  
J Y Chou
Keyword(s):  
Alkaline Phosphatase ◽  
Germ Cell ◽  
Choriocarcinoma Cells ◽  
Human Choriocarcinoma Cells

scholarly journals Expression of different-sized placental alkaline phosphatase mRNAs in placenta and choriocarcinoma cells.

1986 ◽  
Vol 83 (11) ◽  
pp. 3781-3785 ◽  
Author(s):  
C. E. Ovitt ◽  
A. W. Strauss ◽  
D. H. Alpers ◽  
J. Y. Chou ◽  
I. Boime
Keyword(s):  
Alkaline Phosphatase ◽  
Placental Alkaline Phosphatase ◽  
Choriocarcinoma Cells

scholarly journals Induction of germ-cell alkaline phosphatase by butyrate and cyclic AMP in BeWo choriocarcinoma cells

1993 ◽  
Vol 296 (1) ◽  
pp. 59-65 ◽  
Author(s):  
J F Telfer ◽  
C D Green
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Cyclic Amp ◽  
Germ Cell ◽  
Cholera Toxin ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Sodium Butyrate ◽  
Dibutyryl Camp ◽  
Choriocarcinoma Cells

BeWo choriocarcinoma cells synthesize two alkaline phosphatase isoenzymes: germ-cell alkaline phosphatase and tissue-unspecific alkaline phosphatase. We have made use of the differential heat-stabilities of these two isoenzymes to study the induction of germ-cell alkaline phosphatase by sodium butyrate and cyclic AMP (cAMP). Sodium butyrate causes a large induction of germ-cell alkaline phosphatase activity (approx. 35-fold after 96 h) after an initial lag period of 12-24 h. We showed that butyrate increases germ-cell alkaline phosphatase mRNA. Dibutyryl cAMP also induces germ cell alkaline phosphatase (approx. 2.5-fold after 96 h). When optimal concentrations of butyrate and dibutyryl cAMP were added simultaneously to cells, they caused a synergistic induction of activity. This suggested that these compounds use separate mechanisms to induce germ-cell alkaline phosphatase activity and that it is the cAMP moiety of dibutyryl cAMP that induces enzyme activity. This was confirmed by the use of two additional cAMP analogues, 8-(4-chlorophenylthio) cAMP and 8-bromo cAMP, and of two compounds, 3-methyl-1-isobutylxanthine and cholera toxin, which raise the endogenous concentration of cAMP. All four compounds caused a 2-fold increase in enzyme activity. Treatment of cells with 8-(4-chlorophenylthio) cAMP, 8-bromo cAMP and cholera toxin increased germ-cell alkaline phosphatase mRNA between 2- and 7-fold. These data suggest that this alkaline phosphatase isoenzyme is regulated at the level of its mRNA by cAMP, in a manner distinct from that of butyrate.

scholarly journals Regulation of the synthesis of lutropin-induced protein in rat testis Leydig cells

1978 ◽  
Vol 170 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Felix H. A. Janszen ◽  
Brian A. Cooke ◽  
Maria J. A. Van Driel ◽  
Henk J. Van Der Molen
Keyword(s):  
Protein Synthesis ◽  
Cyclic Amp ◽  
Leydig Cells ◽  
Actinomycin D ◽  
Polyacrylamide Gel Electrophoresis ◽  
Phosphodiesterase Inhibitor ◽  
Dibutyryl Cyclic Amp ◽  
Rat Testis ◽  
Stimulation Of

The mechanism of action of lutropin on the stimulation of the synthesis of a specific lutropin-induced protein in rat testis Leydig cells was investigated. Lutropin-induced protein has a mol.wt. of approx. 21000 and is detected by labelling the Leydig-cell proteins with [35S]methionine, followed by separation by polyacrylamide-gel electrophoresis and radioautography of the dried gel. The incorporation of35S into lutropin-induced protein was used as an estimate for the synthesis of the protein. Incubation of Leydig cells with dibutyryl cyclic AMP or cholera toxin also resulted in the stimulation of synthesis of the protein. Synthesis of lutropin-induced protein, when maximally stimulated with 100ng of lutropin/ml, could not be stimulated further by addition of dibutyryl cyclic AMP. Addition of 3-isobutyl-1-methylxanthine, a phosphodiesterase inhibitor, further increased synthesis of the protein in the presence of a submaximal dose of lutropin (10ng/ml) but not in the absence of lutropin or with maximal amounts of lutropin (100 and 1000ng/ml). Actinomycin D prevented the effect of lutropin on the stimulation of lutropin-induced protein synthesis when added immediately or 1h after the start of the incubation, but not when added after 5–6h. This is interpreted as reflecting that, after induction of mRNA coding for lutropin-induced protein, lutropin had no influence on the synthesis of the protein in the presence of actinomycin D. Synthesis of the protein was also stimulated in vivo by injection of choriogonadotropin into rats 1 day after hypophysectomy, and the time course of this stimulation of lutropin-induced protein synthesis in vivo was similar to that obtained by incubating Leydig cells in vitro with lutropin. From these results it is concluded that stimulation of lutropin-induced protein synthesis by lutropin is most probably mediated by cyclic AMP and involves synthesis of mRNA.

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