miR-129 predicts prognosis and inhibits cell growth in human prostate carcinoma

MicroRNAs (miRNAs) are a class of small, well-conserved, non-coding RNAs that are increasingly identified as diagnostic and prognostic biomarkers in a number of cancers. Deregulated miR-129 is closely associated with tumorigenesis and cancer progression. However, the potential role of miR-129 in prostate cancer remains largely elusive. The present study investigated the role of miR-129 as a prognostic biomarker for tumor progression and clinical prognosis in prostate cancer patients. The examined prostate cancer tissues exhibited a significant reduction in miR-129 expression compared with the normal tissues (P=0.013). The expression levels of miR-129 were negatively correlated with histological grade (P<0.001), high preoperative prostate-specific antigen serum levels (P<0.001), pathological stage (P<0.001), high Gleason score (P<0.001), lymph node metastasis (P=0.002), angiolymphatic invasion (P=0.018), and biochemical recurrence (BCR; P=0.001). Use of the Kaplan-Meier analysis demonstrated that low miR-129 expression was closely associated with poorer BCR-free survival. Multivariate survival analysis indicated that miR-129 expression may be an independent prognostic marker for BCR-free survival in prostate cancer patients (P<0.001). Overexpression of miR-129 markedly attenuated prostate cancer cell growth by rescuing cell cycle-regulated protein expression. The present study suggests that miR-129 is downregulated in the cancerous tissues of prostate cancer patients, which was associated with poor BCR-free survival. Thus, it may be considered as a novel independent prognostic biomarker for prostate cancer. In addition, downregulation of miR-129 may serve a critical role in the proliferation of prostate cancer cells.