miR-31-5p Regulates 14-3-3 ε to Inhibit Prostate Cancer 22RV1 Cell Survival and Proliferation via PI3K/AKT/Bcl-2 Signaling Pathway

Introduction: Prostate cancer (PCa) is one of the most common malignancies, and almost all patients with advanced PCa will develop castration-resistant prostate cancer (CRPC) after receiving endocrine therapy. Effective treatment for patients with CRPC has not been established. Novel approaches are needed to identify therapeutic targets for CRPC. Purpose: Recent research studies have found that members of the 14-3-3 family play an important role in the development and progression of PCa. Previous results have shown that 14-3-3 epsilon is significantly upregulated in several cancers. This study aimed to identify novel miRNAs that regulate 14-3-3 epsilon expression and therapeutic targets for CRPC. Methods: In this study, we used computation and experimental approaches for the prediction and verification of the miRNAs targeting 14-3-3 epsilon, and investigated the potential roles of 14-3-3 epsilon in the survival and proliferation of 22RV1 cells. Results: We confirm that mir-31-5p is downregulated in 22RV1 cells and acts as a tumor suppressor by regulating 14-3-3 epsilon. Ectopic expression of miR-31-5p or 14-3-3 epsilon interference significantly inhibits cell proliferation, invasion, and migration in 22RV1 cells, as well as promotes cell apoptosis via the PI3K/AKT/Bcl-2 signaling pathway. Moreover, 14-3-3 epsilon is required for the miR-31-5p-mediated upregulation of the PI3K/AKT/Bcl-2 signaling pathway. Conclusion: Our findings provide information on the underlying mechanisms of miR-31-5p/14-3-3 epsilon in 22RV1 cell proliferation and apoptosis through the PI3K/AKT/Bcl-2 signaling pathway. These results suggest that miR-31-5p and 14-3-3 epsilon may potentially be utilized as novel prognostic markers and therapeutic targets for PCa treatment.