title: Evidence that chlormadinone acetate exhibits antiandrogenic activity in androgen-dependent cell line.
abstract: Chlormadinone acetate (CMA), like other 17-hydroxyprogesterone derivatives, is thought to be a potential antiandrogen on the basis of its effect on spontaneous benign prostatic hyperplasia (BPH) in dogs. This work was undertaken to find out whether CMA presents antiandrogen activity in human androgen-dependent cell line. For this purpose, we used PALM cells, the PC-3 cell line stably transfected with human androgen receptor and a luciferase gene under transcriptional control of MMTV. Potential antiandrogenic activity was compared with that of cyproterone acetate (CPA), a standard steroidal antiandrogen. Both compounds were tested in competitive binding assays at 37 degrees C in the presence of 1 nM of [3H] R1881, a synthetic and non-metabolizable androgen. Their impact on AR transcriptional activity was evaluated by the measure of luciferase activity in the presence of R1881 with increasing concentrations of CMA or CPA (10(-8)-10(-6) M). In whole cell binding assays, competitive studies revealed that the Ki for CMA was 3.3 +/- 1.5 x 10(-8) M (versus 7.2 +/- 1.3 x 10(-8) M for CPA). Inhibition of AR transcriptional activity was 40 +/- 5% for CMA (3 x 10(-7) M) versus 59 +/- 6% for CPA at the same concentration. Moreover, CMA caused a slower import of green fluorescent protein (GFP)-AR to the nuclei of COS-7 cells than R1881. These data show that CMA exerted a competitive binding for AR and significantly decreased the AR transcriptional activity. In conclusion, this synthetic progestin presents simultaneous antiandrogenic activity that could be helpful as a new therapeutic option in women with luteal defect along with clinical signs of hyperandrogenism.
authors.affiliation: INSERM Unité 439, Pathologie Moléculaire des Récepteurs Nucléaires, 70 rue de Navacelles, 34090 Montpellier, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Térouanne
authors.forename: Françoise
authors.initials: F
authors.lastname: Paris
authors.forename: Nadège
authors.initials: N
authors.lastname: Servant
authors.forename: Virginie
authors.initials: V
authors.lastname: Georget
authors.forename: Charles
authors.initials: C
authors.lastname: Sultan
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology; D000726:Androgen Antagonists / Q000737:chemistry / Q000378:metabolism*; D000728:Androgens / Q000819:agonists / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D002715:Chlormadinone Acetate / Q000737:chemistry / Q000378:metabolism*; D017373:Cyproterone Acetate / Q000737:chemistry / Q000378:metabolism; D005260:Female; D017930:Genes, Reporter; D006801:Humans; D008297:Male; D015741:Metribolone / Q000378:metabolism; D015394:Molecular Structure; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D000726:Androgen Antagonists; D000728:Androgens; D011944:Receptors, Androgen; D011993:Recombinant Fusion Proteins; D002715:Chlormadinone Acetate; D015741:Metribolone; D017373:Cyproterone Acetate