Figure 3.

Functional assays of the novel antagonists. HeLa cells were transfected with a Gal4-hRARα-LBD expression vector and a Gal4-CAT reporter gene (results were similar in studies using the three hRAR isoforms). The cells were incubated with 5 nM all-trans RA to stimulate CAT activity, and the effect of each antagonist on inhibiting CAT was examined at 2 and 20 μM concentration (the known antagonist RO-41–5253 was used as a positive control).