Determination of androgen bioactivity in human serum samples using a recombinant cell based in vitro bioassay

Anti-androgenic endocrine disrupting activities of chlorpyrifos and piperophos

“…The basic principle of a robust AR-mediated assay is the utilization of an AR transfected cell line that does not express endogenous 5␣-reductase, 17␤-HSD and 3␤-HSD enzymes that are responsible for metabolizing test steroids or environmental EDCs [18]. Transactivation assays with AR and androgen-responsive reporter genes have been performed using various mammalian cell lines like PC-3, COS, CHO, CV-1, MCF-7 and HepG2, HEK293, MDA-MB-453 cells [2,4,6,7,9,18,[27][28][29]. Of these various transactivation assays many of them utilized the recombinant cell lines stably or transiently expressing AR and androgen-responsive reporter genes both of which are suitable for screening androgenic and anti-androgenic compounds albeit the former one with greater efficiency.…”

“…For the development of reporter based assays, generally, cell lines lacking the endogenous AR are stably or transiently co-transfected with either human or rat AR expression plasmid in combination with a reporter plasmid containing either chloramphenicol acetyl transferase (CAT) or a luciferase gene under transcriptional control of the MMTV promoter. A wide range of cell lines like CHO-K1, COS1, COS7, CV1, MDA-kb-2, PC3, human U2-OS have been used for this purpose [2,[4][5][6][7][8][9][10].…”

Structure–activity relationships of synthetic progestins in a yeast-based in vitro androgen bioassay

“…The most potent androgen tested in this study, altrenogest, had a 17␣-allyl substitution in the 4,9,11-triene backbone. The potency of this substitution was not maintained however in the 4-ene derivatives of 17␣-allylnandrolone (16) and 17␣-allyl-18-methylnandrolone (19) (Fig. 2).…”

“…Measurement of receptor interaction by yeast assay has proven robust and reproducible in a wide variety of pharmacological and toxicological contexts and is a rapid and inexpensive first pass screen to determine relative relationships between structure and bioactivity [15][16][17][18][19][20]. Yeast lack homologous steroid hormone receptors yet contain enough conserved basal transcriptional machinery to allow a recombinant human receptor to facilitate the transcription of a co-transformed reporter vector (␤-galactosidase) linked to a steroid responsive promoter [21].…”

Serum oestrogen receptor α and β bioactivity are independently associated with breast cancer: a proof of principle study

“…Over the last decade, several groups have developed bioactivity assays for steroid hormones mainly to detect very-low hormone levels in children (Klein et al, 1994(Klein et al, , 1998Paris et al, 2002;Roy et al, 2006). Recently, we have described a receptor ERE-green fluorescent protein (GFP)-reporter test system in Saccharomyces cerevisiae, which measures activation of ER-a and ER-b independently.…”