Abstract

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.

Introduction

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men worldwide and it is the fifth leading cause of cancer deaths.1 Historically, PCa has provided important knowledge to the areas of early diagnosis and treatment of cancer, from highly-sensitive PSA screening and the modern radical prostatectomy, to the current recognition of PCa over-diagnosis and over-treatment of indolent disease. PCa was one of the first solid tumors with a targeted treatment for metastatic disease through androgen deprivation therapy (ADT), which has provided important clinical, molecular, and genetic knowledge of pathways that contribute to cancer progression and tumor cell therapeutic resistance. The PCa field is again paving new paths in cancer management through the active surveillance of low-risk disease, as opposed to more radical treatments, and through the development and approval of several novel targeted drugs for metastatic disease and the metastatic microenvironment.2–۴ As more is discovered about PCa biology and as PCa management evolves, our knowledge of microRNA (miRNA) biology and expression has grown. Here, we review the recent discoveries of numerous miRNAs reported to be associated with PCa, and we consider the potential contributions of these miRNAs to PCa biology and cancer management.