AKR1C3 mediates pan-AR antagonist resistance in castration-resistant prostate cancer.

Background Antiandrogens are effective therapies that block androgen receptor (AR) transactivation and signaling in over 50% of castration-resistant prostate cancer (CRPC) patients. However, an estimated 30% of responders will develop resistance to these therapies within 2 years. JNJ-pan-AR is a broad-spectrum AR antagonist that inhibits wild-type AR as well as several mutated versions of AR that have emerged in patients on chronic antiandrogen treatment. In this work, we aimed to identify the potential underlying mechanisms of resistance that may result from chronic JNJ-pan-AR treatment. Methods The LNCaP JNJR prostate cancer subline was developed by chronically exposing LNCaP parental cells to JNJ-pan-AR. Transcriptomic and proteomic profiling was performed to identify potential drivers and/or biomarkers of the resistant phenotype. Results Several enzymes critical to intratumoral androgen biosynthesis, Aldo-keto reductase family 1 member C3 (AKR1C3), UGT2B15, and UGT2B17 were identified as potential upstream regulators of the JNJ-pan-AR resistant cells. While we confirmed the overexpression of all three enzymes in the resistant cells only AKR1C3 expression played a functional role in driving JNJ-pan-AR resistance. We also discovered that AKR1C3 regulates UGT2B15 and UGT2B17 expression in JNJ-pan-AR resistant cells. Conclusions This study supports the rationale to further investigate the benefits of AKR1C3 inhibition in combination with antiandrogens to prevent CRPC disease progression.