title: Interlaboratory comparison of four in vitro assays for assessing androgenic and antiandrogenic activity of environmental chemicals.
abstract: We evaluated and compared four in vitro assays to detect androgen agonists and antagonists in an international interlaboratory study. Laboratory 1 used a cell proliferation assay (assay 1) with human mammary carcinoma cells stably transfected with human androgen receptor. The other laboratories used reporter gene assays, two based on stably transfected human prostate carcinoma cells (assay 2) or human mammary carcinoma cells (assay 4), and the third based on transient transfection of Chinese hamster ovary cells (assay 3). Four laboratories received four coded compounds and two controls: two steroidal androgens, two antiandrogens, an androgenic control, 5alpha-dihydrotestosterone (DHT), and an antiandrogenic control, bicalutamide (ICI 176,334). All laboratories correctly detected the androgenic activity of 4-androsten-3,17-dione and 17alpha-methyltestosterone. For both compounds, the calculated androgenic potencies relative to the positive control (RAPs) remained within one order of magnitude. However, laboratory 3 calculated a 50-fold higher RAP for 4-androsten-3,17-dione. All assays detected and quantified the antiandrogenic effect of vinclozolin [median inhibitory concentration (IC50) values ranging from 1.1 times symbol 10(-7) M to 4.7 times symbol 10(-7) M]. In assays 2 and 3, vinclozolin showed partial androgenic activity at the highest concentrations tested. For vinclozolin, calculated antiandrogenic potencies relative to bicalutamide (RAAPs) differed no more than a factor of 10, and IC50 values matched those of bicalutamide. Similarly, we found antiandrogenic activity for tris-(4-chlorophenyl)methanol. RAAP values were between 0.086 and 0.37. Three assays showed cytotoxicity for this compound at or above 1 times symbol 10(-5) M. In summary, all assays proved sensitive screening tools to detect and quantify androgen receptor-mediated androgenic and antiandrogenic effects of these chemicals accurately, with coefficients of variation between 8 and 90%.
authors.affiliation: Bayerisches Landesamt für Umweltschutz, Augsburg, Germany. wolfgang.koerner@lfu.bayern.de
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Körner
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Vinggaard
authors.forename: Béatrice
authors.initials: B
authors.lastname: Térouanne
authors.forename: Risheng
authors.initials: R
authors.lastname: Ma
authors.forename: Carise
authors.initials: C
authors.lastname: Wieloch
authors.forename: Margret
authors.initials: M
authors.lastname: Schlumpf
authors.forename: Charles
authors.initials: C
authors.lastname: Sultan
authors.forename: Ana M
authors.initials: AM
authors.lastname: Soto
mesh_terms: D000726:Androgen Antagonists / Q000494:pharmacology*; D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D001681:Biological Assay; D001943:Breast Neoplasms / Q000473:pathology; D016466:CHO Cells; D002455:Cell Division / Q000187:drug effects; D006224:Cricetinae; D004785:Environmental Pollutants / Q000494:pharmacology*; D005260:Female; D006801:Humans; D015588:Observer Variation; D011944:Receptors, Androgen / Q000187:drug effects*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured / Q000473:pathology
chemical_list: D000726:Androgen Antagonists; D000728:Androgens; D004785:Environmental Pollutants; D011944:Receptors, Androgen