Christian Gege

Structure-based design, synthesis and in vitro characterization of potent 17β-hydroxysteroid dehydrogenase type 1 inhibitors based on 2-substitutions of estrone and D-homo-estrone

In search for specific drugs against steroid-dependent cancers we have developed a novel set of potent inhibitors of steroidogenic human 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD 1). The X-ray structure of 17beta-HSD 1 in complex with estradiol served as basis for the design of the inhibitors. 2-Substituted estrone and D-homo-estrone derivatives were synthesized and tested for 17beta-HSD 1 inhibition. The best 17beta-HSD 1 inhibitor, 2-phenethyl-D-homo-estrone, revealed an IC(50) of 15 nM in vitro. The inhibitory potency of compounds is comparable or better to that of previously described inhibitors. An interaction within the cofactor binding site is not necessary to obtain this high binding affinity for substances developed.

Identification of the first inverse agonist of retinoid-related orphan receptor (ROR) with dual selectivity for RORβ and RORγt

Retinoic acid receptor-related orphan nuclear receptor gamma t (RORγt) is a key transcription factor for the development of Th17 cells. Inhibiting RORγt activity is thought to be beneficial in targeting a variety of inflammatory and autoimmune disorders. Recently N-(5-(arylcarbonyl)thiazol-2-yl)amides were described as RORγt antagonists with in vivo efficacy in experimental autoimmune encephalomyelitis (EAE) and collagen-induced arthritis (CIA) via oral administration. So far no selective small molecule ligands have been revealed for RORβ. We show, that one compound of this class, namely N-[5-(2-chloro-benzoyl)-4-(3-chlorophenyl)-thiazol-2-yl]-2-(4-ethanesulfonyl-phenyl)-acetamide (4) is a potent dual inverse agonist towards RORγt and RORβ devoid of activity to 18 other human nuclear receptors and thus can serve as chemical probe to deepen our understanding about RORβ and its biology.