miR-505 suppresses prostate cancer progression by targeting NRCAM

Previous researchers have demonstrated that microRNA-505 (miR-505) is negatively correlated with progression in various malignancies. However, the detailed function and molecular mechanisms of miR-505 have yet to be completely elucidated in prostate cancer (PCa). The present study initially identified the potential role of miR-505 in PCa using in vitro experiments, and demonstrated that restoration of miR-505 inhibited proliferation, invasion and migration, yet induced cell cycle arrest and promoted apoptosis in PCa cells. The present study also demonstrated that the expression of neuron-glial-related cell adhesion molecule (NRCAM) was markedly upregulated in PCa cells when compared with benign prostate epithelium. A luciferase reporter assay demonstrated that miR-505 directly targeted NRCAM in PCa cells. In addition, NRCAM stimulation antagonized the inhibitory effects of miR-505 on the proliferation, migration, and invasion of PCa cells. Furthermore, lower levels of miR-505 and higher levels of NRCAM may serve as a predictor of worse biochemical recurrence-free survival or disease-free survival in patients with PCa. In conclusion, the present study revealed the inhibitory effects of miR-505 on PCa tumorigenesis, which potentially occur by targeting NRCAM. The combined analysis of NRCAM and miR-505 may predict disease progression in patients with PCa following radical prostatectomy.