Design, synthesis and biological evaluation of tetrazole-containing RXRα ligands as anticancer agents.

Nuclear receptor RXRα plays an important role in many biological and pathological processes. The nongenomic action of RXRα is implicated in many cancers. K-8008, a non-canonical RXRα ligand derived from sulindac, inhibits the TNFα-activated PI3K/AKT pathway by mediating the interaction between a truncated form of RXRα (tRXRα) and the p85α regulatory subunit of PI3K and exerts potent anticancer activity in animal model. Herein we report our studies of a novel series of K-8008 analogs as potential anticancer agents targeting RXRα. Two compounds 8b and 18a were identified to have slightly stronger binding to RXRα and improved apoptotic activities in breast cancer cells.