Interaction of antiandrogen-androgen receptor complexes with DNA and transcription activation.
Human androgen receptor (hAR) is a ligand-dependent transcription factor that mediates androgen-induced actions on target tissues. Transfection studies in receptor deficient monkey kidney cells CV-1 in culture examine the ability of dihydrotestosterone (DHT) and of the antiandrogens hydroxylflutamide (HO-FLU), cyproterone acetate (Cypro.A) and RU 23908-10 to stimulate or to inhibit the transcription activation of mouse mammary tumor virus-bacterial chloramphenicol acetyltransferase (MMTV-CAT). CV-1 cells cotransfected with wild type hAR (hAR1-910) and MMTV-CAT, were treated with varying concentrations of DHT. DHT stimulated transcription activation of MMTV-CAT gene in a dose-dependent fashion. Cypro.A though only partially, also stimulated the transcription activation of MMTV-CAT. In the absence of steroids, HO-FLU induced the MMTV-CAT transcription in transfectants only 4% above the basal level. RU 23908-10 revealed the least agonistic activity at concentrations between 10 nM and 1 microM. Despite this, 100- to 1000-fold molar excess of all antiandrogens inhibited the agonistic activity of 10 nM DHT in this system. Receptor binding assays confirmed that HO-FLU, Cypro.A and RU 23908-10 competed with [3H]DHT for AR binding with hAR expressed in CV-1 cells. Western blot analysis using AR antipeptide antibodies raised in rabbits revealed the presence of two AR protein bands in extracts prepared from hAR1-910 transfected CV-1 cells. Incubation of labeled synthetic palindromic androgen responsive element (ARE) with the hAR containing CV-1 cell extracts followed by u.v. cross-linking demonstrated the specificity of AR-DNA interaction. Analysis by gel mobility shift assays showed that the interaction of AR-antiandrogen complexes with labeled ARE was specific.
Warriar
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MRC Group in Molecular Endocrinology, CHUL Research Center, Quebec, Canada.
Pagé
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Koutsilieris
M
M
Govindan
M V
MV
D000726:Androgen Antagonists / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D015153:Blotting, Western; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis / Q000378:metabolism; D002522:Chlorocebus aethiops; D017373:Cyproterone Acetate / Q000494:pharmacology; D004247:DNA / Q000378:metabolism*; D013196:Dihydrotestosterone / Q000378:metabolism; D005485:Flutamide / Q000031:analogs & derivatives / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D048289:Imidazolidines; D007668:Kidney; D007700:Kinetics; D008324:Mammary Tumor Virus, Mouse / Q000187:drug effects / Q000235:genetics; D015741:Metribolone / Q000378:metabolism; D011944:Receptors, Androgen / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism; D014157:Transcription Factors / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation / Q000187:drug effects; D014162:Transfection
D000726:Androgen Antagonists; D007093:Imidazoles; D048289:Imidazolidines; D011944:Receptors, Androgen; D011994:Recombinant Proteins; D014157:Transcription Factors; D013196:Dihydrotestosterone; D015741:Metribolone; C014290:hydroxyflutamide; D017373:Cyproterone Acetate; C021277:nilutamide; D005485:Flutamide; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase