Enhanced RAR transcriptional activity in EML/GM-CSF cells.

The indicated cells were transfected with the RXR/RAR-responsive RARE tk-LUC reporter and then cultured for 5 hours in the indicated concentrations of ATRA. Relative luciferase activity was then determined on harvested cell extracts using a β-galactosidase reporter as an internal control as detailed in “Materials and methods.” The results represent the mean of at least 3 independent experiments.