Biochem/physiol Actions
Pyrvinium pamoate is a potent androgen receptor inhibitor. Androgen receptors (ARs) are nuclear hormone receptors/transcription factors that reside in the cytoplasm and activated by testosterone and dihydrotestosterone. AR inhibitors have potential therapeutic benefit in prostate cancer; competitive inhibitors and chemical castration methods have been discovered, but both therapies have undesirable side effects and/or resistance potential. A screen for non-competitive inhibitors was performed, resulting in the discovery of pyrvinium as an AR inhibitor. In comparison to competitive inhibitors, this compound does not bind to the ligand-binding domain of AR or block DNA occupancy by AR, but it inhibits AR-dependent gene expression via a distinct signaling mechanism. It is more potent than classical competitive AR antagonists and exhibits synergy with other AR inhibitors. |