MicroRNA expression and function in prostate cancer: a review of current knowledge and opportunities for discovery

MicroRNAs (miRNAs) are well-conserved noncoding RNAs that broadly regulate gene expression through posttranscriptional silencing of coding genes. Dysregulated miRNA expression in prostate and other cancers implicates their role in cancer biology. Moreover, functional studies provide support for the contribution of miRNAs to several key pathways in cancer initiation and progression. Comparative analyses of miRNA gene expression between malignant and nonmalignant prostate tissues, healthy controls and prostate cancer (PCa) patients, as well as less aggressive versus more aggressive disease indicate that miRNAs may be future diagnostic or prognostic biomarkers in tumor tissue, blood, or urine. Further, miRNAs may be future therapeutics or therapeutic targets. In this review, we examine the miRNAs most commonly observed to be de-regulated in PCa gene expression analyses and review the potential contribution of these miRNAs to important pathways in PCa initiation and progression.