Abstract
MicroRNAs (miRNAs) have been reported to participate in many biological behaviours of multiple malignancies. Recent studies have shown that miR-15b-5p (miR-15b) exhibits dual roles by accelerating or blocking tumour progression. However, the molecular mechanisms by which miR-15b contributes to prostate cancer (PCa) are still elusive. Here, miR-15b expression was found significantly up-regulated in PCa in comparison with the normal samples and was positively correlated with age and Gleason score in patients with PCa. Notably, PCa patients with miR-15b high expression displayed a higher recurrence rate than those with miR-15b low expression (P = 0.0058). Knockdown of miR-15b suppressed cell growth and invasiveness in 22RV1 and PC3 cells, while overexpression of miR-15b reversed these effects. Then, we validated that RECK acted as a direct target of miR-15b by dual-luciferase assay and revealed the negative correlation of RECK with miR-15b expression in PCa tissues. Ectopic expression of RECK reduced cell proliferation and invasive potential and partially abrogated the tumour-promoting effects caused by miR-15b overexpression. Additionally, miR-15b knockdown inhibited tumour growth activity in a mouse PCa xenograft model. Taken together, our findings indicate that miR-15b promotes the progression of PCa cells by targeting RECK and represents a potential marker for patients with PCa.