Test No. 455: Performance-Based Test Guideline for Stably Transfected Transactivation
In Vitro Assays to Detect Estrogen Receptor Agonists and Antagonists
This Performance-Based Test Guideline (PBTG) describes in vitro assays, which provide
the methodology of Stably Transfected Transactivation to detect Estrogen Receptor
Agonists and Antagonists (ER TA assays). It comprises mechanistically and functionally
similar test methods for the identification of estrogen receptor agonists and antagonists
and should facilitate the development of new similar or modified test methods. The
two reference test methods that provide the basis for this PBTG are: the Stably Transfected
TA (STTA) assay using the (h) ERα-HeLa-9903 cell line, derived from a human cervical
tumor, and the BG1Luc ER TA assay using the BG1Luc-4E2 cell line, derived from a human
ovarian adenocarcinoma. The cell lines used in these assays express ER and have been
stably transfected with an ER responsive luciferase reporter gene. The assays are
used to identify chemicals that activate (i.e. act as agonists) and also suppress
(i.e. act as antagonists) ER- dependent transcription. ER are activated following
ligand binding, after which the receptor-ligand complex binds to specific DNA response
elements and transactivates the reporter gene, resulting in increased cellular expression
of a marker enzyme (e.g. luciferase in luciferase based systems). The enzyme then
transforms the substrate to a bioluminescent product that can be quantitatively measured
with a luminometer. These test methods are being proposed for screening and prioritisation
purposes, but also provide mechanistic information that can be used in a weight of
evidence approach.
Available from June 17, 2021Also available in: French
In series:OECD Guidelines for the Testing of Chemicals, Section 4: Health Effectsview more titles