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PubMed · 1322276

Epidermal growth factor, a phorbol ester, and 3',5'-cyclic adenosine monophosphate decrease the transcription of the luteinizing hormone/chorionic gonadotropin receptor gene in MA-10 Leydig tumor cells.

S Nelson·M Ascoli
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Abstract

In a recent series of experiments we have shown that the previously recognized ability of mouse epidermal growth factor (mEGF), cAMP, or phorbol 12-myristate 13-acetate (PMA) to reduce the density of LH/CG receptors in MA-10 cells is secondary to a reduction in receptor messenger RNA (mRNA). As a follow-up to these studies we now present experiments designed to determine if the reduction in LH/CG receptor mRNA is due to a decrease in transcription of the receptor gene and/or an increase in the rate of degradation of the mRNA. The potential effects of mEGF, cAMP, or PMA on the degradation of the LH/CG receptor mRNA were measured in MA-10 cells treated with Actinomycin D or in kidney cells permanently transfected with the LH/CG receptor complementary DNA driven by a heterologous promoter. Both experimental strategies revealed that none of these compounds increase the rate of degradation of the receptor mRNA. If anything, a stabilizing effect was noted. The potential effects of mEGF, cAMP, or PMA on the transcription of the LH/CG receptor gene in MA-10 cells were measured using nuclear run-off assays. All three compounds induced a rapid decrease in the transcription of the LH/CG receptor gene. The time course of these effects is similar, and by 2 h all of the stimuli had decreased transcription to 15-30% of control. Our studies show that the mEGF-, cAMP- and PMA-induced down-regulation of the LH/CG receptor in MA-10 cells is primarily (if not entirely) due to a decrease in the transcription of the receptor gene.

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8-Bromo Cyclic Adenosine MonophosphateCyclic AMPDNADactinomycinEpidermal Growth FactorHumansKineticsLeydig Cell TumorRNA, MessengerReceptors, LHTetradecanoylphorbol AcetateTranscription, GeneticTransfectionTumor Cells, CulturedJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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S Nelson, M Ascoli. 1992. Epidermal growth factor, a phorbol ester, and 3',5'-cyclic adenosine monophosphate decrease the transcription of the luteinizing hormone/chorionic gonadotropin receptor gene in MA-10 Leydig tumor cells.. https://doi.org/10.1210/endo.131.2.1322276

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