functional GR was stably integrated to make the EcR-GR cells, a generalized repression of SEPP1 was observed compared to the 293-EcR cells. This data supports the idea that the GR may indirectly regulate expression of this gene, and this effect was further validated by the evaluation of the protein levels of SelP expressed in the EcR-GR cells. An indirect mechanism of GR modulation of transcription has been described previously through the interaction with CCAAT/enhancer-binding proteins (Rudiger et al. 2002). These proteins are involved in a broad spectrum of biological activities including development and differentiation (Ramji & Foka 2002). Whether a GR interaction with a CCAAT/enhancer-binding protein might be involved in SEPP1 regulation will require further study, and the precise cause for the repression observed in this study is unknown; however, transfection of GRs has previously been shown to be sufficient for the repression of hormone-responsive genes (Gougat et al. 2002).
