show Abstracthide AbstractAndrogen receptor (AR) splice variants (ARVs) are implicated in developing castration-resistant (CR) prostate cancer (CRPC). Little is known about the ARV-mediated transcription program in CRPC. We identified ARV-preferred binding sites (ARV-PBS) and unique transcriptome in CRPC cells. ARVs preferentially bind to enhancers located in nucleosome-depleted regions with the full AR-response element (AREfull), while full-length AR (ARFL)-PBS are enhancers resided in closed chromatin regions with the composite FOXA1-nnnn-AREhalf motif. ARV-PBS exclusively overlapped with AR binding sites in CR patients. ARV-driven genes were up-regulated in abiraterone-resistant patient specimens and promote CRPC growth. We uncover distinct genomic and epigenomic characteristics of ARV-PBS and a unique ARV-dependent transcriptional program that not only drives CR progression but could also offer new targets for therapy. Increasing evidence suggests a pivotal role of ARVs in the acquisition of anti-AR therapy resistance in CRPC. It has been shown previously that ARVs possess unique structural and functional features such as completely lacking or only containing an impaired ligand-binding domain but constitutively active. Our findings advance the understanding of ARVs by demonstrating that ARV-PBS exhibit distinctive DNA-binding motif, GC content, and nucleosome and epigenetic characteristics. We further unravel that ARV-PBS exclusively overlap with AR bindings identified from castration-resistant patients and ARV activity is significantly increased in abiraterone-resistant patients. Given that there is no drug available to target ARVs at present, identification of ARV-mediated unique downstream pathways opens new avenues for the development of effective therapeutics for CRPC. Overall design: ARVs preferred binding sites (ARV-PBS) were identified from regular AR ChIP-seq experiments after knocking down AR full length (ARFL) in 22Rv1 (R1881-). ARFL preferred binding sites (ARFL-PBS) were identified from regular AR ChIP-seq experiments after knocking down AR-V1, AR-V3, AR-V4 and AR-V7 in 22Rv1 (R1881+).