LX1 Dual Targets AR Variants and AKR1C3 in Advanced Prostate Cancer Therapy

The development of resistance to current standard-of-care treatments, such as androgen receptor (AR) targeting therapies, remains a major challenge in the management of advanced prostate cancer. There is an urgent need for new therapeutic strategies targeting key resistant drivers such as AR variants like AR-V7 and steroidogenic enzymes such as AKR1C3 to overcome drug resistance and improve outcomes for patients with advanced prostate cancer. Here we have designed, synthesized, and characterized a novel class of LX compounds targeting both the AR/AR-Variants and AKR1C3 pathways. Molecular docking and in vitro studies demonstrated that LX compounds bind to the AKR1C3 active sites and inhibit AKR1C3 enzymatic activity. LX compounds were also shown to reduce AR/AR-V7 expression and inhibit their target gene signaling. LX1 inhibited the conversion of androstenedione into testosterone in tumor-based ex vivo enzyme assays. In addition, LX1 inhibited the growth of cells resistant to antiandrogens including enzalutamide, abiraterone, apalutamide and darolutamide in vitro. A synergistic effect was observed when LX1 was combined with antiandrogens and taxanes, indicating the potential for this combination in treating resistant prostate cancer. Treatment with LX1 significantly decreased tumor volume, serum PSA levels, as well as reduced intratumoral testosterone levels, without affecting mouse body weight. Furthermore, LX1 was found to overcome resistance to enzalutamide treatment, and its combination with enzalutamide further suppressed tumor growth in both the CWR22Rv1 xenograft and LuCaP35CR PDX models. Collectively, the dual effect of LX1 in reducing AR signaling and intratumoral testosterone, along with its synergy with standard therapies in resistant models, underscores its potential as a valuable treatment option for advanced prostate cancer. To investigate the dual targeting effects of LXs compounds in advanced prostate cancer, we employed castration-resistant prostate cancer cells with enzalutamide resistance C4-2B MDVR cells treated with DMSO, LX1 and LX5 at 5μM for 48h incubation, and LuCaP35CR patient-derived xenograft tumor models treated with vehicle control and LX1 at 90mg/kg, p.o.. We then performed gene expression profiling analysis using data obtained from RNA-seq.