Synthesis and in vitro characterization of ionone-based compounds as dual inhibitors of the androgen receptor and NF-κB

Current therapeutic strategy for advanced prostate cancer is to suppress the androgen receptor (AR) signaling. However, lethal castration-resistant prostate cancer (CRPC) arises due to AR reactivation via multiple mechanisms, including mutations in the AR and cross-talk with other pathways such as NF-kappa B. We have previously identified two ionone-based antiandrogens (SC97 and SC245), which are full antagonists of the wild type and the clinically-relevant T877A, W741C and H874Y mutated ARs. Here, we discovered SC97 and SC245 also inhibit NF-kappa B. By synthesizing a series of derivatives of these two compounds, we have discovered a novel compound 3b that potently inhibits both AR and NF-kappa B signalling, including the AR F876L mutant. Compound 3b showed low micromolar antiproliferative activites in C4-2B and 22Rv1 cells, which express mutated ARs and are androgen-independent, as well as DU-145 and PC-3 cells, which exhibit constitutively activated NF-kappa B signalling. Our studies indicate 3b is effective against the CRPC cells.