Reporter cell lines are useful tools for monitoring biological activity of nuclear receptor ligands

To characterize the specificity of synthetic compounds for nuclear receptors, we established stable cell lines expressing the luciferase gene and different wild‐type or chimaeric receptors. MCF‐7 cells, which express the oestrogen receptor α (ERα), and HeLa cells, which do not express the oestrogen receptor, were transfected with a plasmid containing the luciferase gene downstream from a minimum promoter (β‐globin) and an oestrogen‐responsive element, generating the MELN and the HELN cell lines, respectively. MELN cells enabled the detection of compounds that bind to the ERα or interfere with its pathway. HELN cells were used to establish stable transfectants expressing different nuclear receptors containing the DNA‐binding domain of the oestrogen receptors. We thus established ERα or ERβ reporter cell lines by transfecting ERα or ERβ expression plasmids, and also retinoic acid receptor α, β or γ reporter cell lines by transfecting the chimaeric RAR gene, in which the DNA‐binding domain was replaced by the ERα DNA‐binding domain. Copyright © 2001 John Wiley & Sons, Ltd.