RESUMEN
Among the known nuclear exportins, CRM1 is the most studied prototype. Dysregulation of CRM1 occurs in many cancers, hence, understanding the role of CRM1 in cancer can help in developing synergistic therapeutics. The study investigates how CRM1 affects prostate cancer growth and survival. It examines the role of CRM1 in regulating androgen receptor (AR) and DNA repair in prostate cancer. Our findings reveal that CRM1 influences AR mRNA and protein stability, leading to a loss of AR protein upon CRM1 inhibition. Furthermore, it highlights the involvement of HSP90 alpha, a known AR chaperone, in the CRM1-dependent regulation of AR protein stability. The combination of CRM1 inhibition with an HSP90 inhibitor demonstrates potent effects on decreasing prostate cancer cell growth and survival. The study further explores the influence of CRM1 on DNA repair proteins and proposes a strategy of combining CRM1 inhibitors with DNA repair pathway inhibitors to decrease prostate cancer growth. Overall, the findings suggest that CRM1 plays a crucial role in prostate cancer growth, and a combination of inhibitors targeting CRM1 and DNA repair pathways could be a promising therapeutic strategy.
RESUMEN
The discovery that androgens play an important role in the progression of prostate cancer led to the development of androgen deprivation therapy (ADT) as a first line of treatment. However, paradoxical growth inhibition has been observed in a subset of prostate cancer upon administration of supraphysiologic levels of testosterone (SupraT), both experimentally and clinically. Here we report that SupraT activates cytoplasmic nucleic acid sensors and induces growth inhibition of SupraT-sensitive prostate cancer cells. This was initiated by the induction of two parallel autophagy-mediated processes, namely, ferritinophagy and nucleophagy. Consequently, autophagosomal DNA activated nucleic acid sensors converge on NFκB to drive immune signaling pathways. Chemokines and cytokines secreted by the tumor cells in response to SupraT resulted in increased migration of cytotoxic immune cells to tumor beds in xenograft models and patient tumors. Collectively, these findings indicate that SupraT may inhibit a subset of prostate cancer by activating nucleic acid sensors and downstream immune signaling. SIGNIFICANCE: This study demonstrates that supraphysiologic testosterone induces two parallel autophagy-mediated processes, ferritinophagy and nucleophagy, which then activate nucleic acid sensors to drive immune signaling pathways in prostate cancer.
