Development of an Androgen Receptor Inhibitor Targeting the N-Terminal Domain of Androgen Receptor for Treatment of Castration Resistant Prostate Cancer

Prostate cancer patients undergoing androgen deprivation therapy almost invariably develop castration-resistant prostate cancer. Resistance occurs when mutations in the androgen receptor (AR) render anti-androgen drugs ineffective or when constitutively active splice variants lacking the androgen binding domain entirely (e.g. ARV7) is expressed. In this study, we are reporting the discovery of novel AR-NTD covalent inhibitor 1-chloro-3-[(5-([(2S)-3-chloro-2-hydroxypropyl]amino)naphthalen-1-yl)amino]propan-2-ol (VPC-220010) targeting the AR-N-terminal Domain (AR-NTD). VPC-220010 inhibits AR-mediated transcription of full length and truncated variant ARV7, downregulates AR response genes, and selectively reduces the growth of both full-length AR- and truncated AR-dependent prostate cancer cell lines. We show that VPC-220010 disrupts interactions between AR and its known coactivators and interactors, such as CHD4, FOXA1, ZMIZ1, and several SWI/SNF complex proteins. Taken together, our data suggest that VPC-220010 is a promising small molecule AR-NTD inhibitor for the treatment of CRPC. Overall design: Polyadenylated RNA profiles of LNCaP cells treated with dihydrotestosterone (DHT) plus either DMSO (Control), Enzalutamide, or VPC-220010, in three biological replicates, obtained using BGISeq500 platform.