Optimization and prevalidation of the in vitro ERα CALUX method to test estrogenic and antiestrogenic activity of compounds

• Published in: Reproductive toxicology (Elmsford, N.Y.) Vol. 30; no. 1; pp. 73 - 80
• Main Authors: van der Burg, Bart, Winter, Roos, Weimer, Marc, Berckmans, Pascale, Suzuki, Go, Gijsbers, Linda, Jonas, Arjen, van der Linden, Sander, Witters, Hilda, Aarts, Jac, Legler, Juliette, Kopp-Schneider, Annette, Bremer, Susanne
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-08-2010
• Subjects: androgen; Antiestrogen; beta; bioassays; cell-line; chemicals; endocrine disruptors; Estrogen; In vitro; panel; Reporter gene assay; transactivation assay; Uterotrophic assay; Validation; Validation; Reporter gene assay; Uterotrophic assay; In vitro; Estrogen; Antiestrogen
• ISSN: 0890-6238; 1873-1708
• DOI: 10.1016/j.reprotox.2010.04.007

Estrogenicity of chemicals has received significant attention and is linked to endocrine-disrupting activities. However, there is a paucity of validated methods to assess estrogenicity
in vitro. We have established a robust method to test estrogenic and antiestrogenic activity of compounds
in vitro, as an alternative to using animal models such as the uterotrophic assay. To this end we optimized protocols to be used in combination with CALUX reporter gene assays and carried out an in house prevalidation, followed by two rounds of tests to establish transferability. Problems in the initial test with transferability were solved by isolation of a novel cell clone of the ERα CALUX line with greatly improved stability and luciferase levels. This cell line proved to be a very suitable and reliable predictor of estrogenicity of chemicals and was able to readily rank a range of chemicals on the basis of their EC50 values.