Abstract
Treatment of MCF-7 cells with the phorbol ester 12- O-tetradecanoylphorbol-13-acetate (TPA) (10 −7 M) was associated with a time-dependent increase in specific binding of [ 3H]dexamethasone (34.8 ± 4.6 fmol/mg protein after9 h of TPA treatment compared with 16.0 ± 2.3 fmol/mg protein in control cells) as well as a transient induction in the level of glucocorticoid receptor (GR) mRNA (4- to 8-fold stimulation after 2–3 h, followed by a decline towards the control value after 6h). In the presence of the transcription inhibitor actinomycin D (AMD) 5.0 μg/ml) the TPA-dependent induction of GR mRNA was completely abolished, and GR mRNA showed a gradual decline with a half-life of 2–3 h. In contrast , treatment with TPA and the protein synthesis inhibitor cycloheximide (50 μM) resulted in a superinduction of GR mRNA ( > 50-fold after 6 h). Inhibition of transcription by AMD after 3 h of TPA treatment was associated with a decay of GR mRNA with a half-life of 2–3 h, which is identical to that observed in non-treated cells. We conclude that the increase in GR mRNA in the presence of TPA is dependent on ongoing transcription, whereas the rate by which GR transcripts are degraded, is not altered by TPA.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Steroid Biochemistry and Molecular Biology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
