MicroRNA-506 as a tumor suppressor in prostate cancer by regulation of Hippo signaling pathway

Introduction: Prostate cancer (PCa) is considered as one of the leading causes of cancer related deaths among males globally. There is a high rate of tumor relapse and metastasis in PCa patients that is associated with chemoresistance. Beside the elimination of tumor cells, chemotherapy has an adverse effect in normal cells. Therefore, it is required to clarify the molecular tumor biology to introduce novel markers to predict the drug response in PCa patients. Hippo signaling pathway is an important regulator of cell proliferation, migration, and drug response that can be modulated by microRNAs (miRNAs). Since, miR-506 deregulation has been reported in PCs, in the present study we assessed a probable role of miR-506 in regulation of Hippo signaling pathway during prostate tumor cell migration and drug resistance. Materials and methods: The mRNA expression levels of Hippo signaling components were assessed in miR-506 ectopic expressed in comparison with control PC3 cells. Apoptosis assay, drug response, and cell migration were also assessed to find the role of miR-506 in prostate tumor cell aggressiveness. Results: MiR-506 promoted the Hippo signaling pathway via TAZ and CTGF up regulations, while BIRC5, FAT, and C-MYC down regulations in PC3 cells. MiR-506 significantly reduced prostate tumor cell migration (p p = 0.019) and Paclitaxel (TXL) resistance (p p = 0.0006), while promoted apoptosis (p p < 0.0001). Conclusion: miR-506 exerted a tumor suppressor role during PCa progression by activation of Hippo pathway. MiR-506 targeted the FAT to activate the YAP/TAZ and nuclear translocation where it can bind with TEAD to up regulate the CTGF that resulted in reduced PCa cell migration. The WNT inhibition and C-MYC down regulation by the CTGF resulted in BIRC5 down regulation that induced apoptosis in PCa cells. Therefore, miR-506 can be introduced as a therapeutic marker in PCa following the confirmation by the animal studies and further clinical trials.