MicroRNA in prostate cancer: Practical aspects.

In the last decade, microRNAs (miRNAs) have emerged as biomarkers for cancer diagnosis, prognosis, therapy and prediction of treatment response and have earned a promising role in prostate cancer (PCa) management. A plethora of studies has been conducted on miRNA expression in PCa compared to non-neoplastic prostatic tissue, in PCa of different histologic grades and pathologic stages, in castration resistance prostate cancer (CRPC), in metastatic disease and in response to therapy, with evidence pointing towards distinctive miRNAs differentially expressed in each of these phases. In addition to tissue, miRNA can be detected in blood, serum, and urine. The aim of this review is to survey studies conducted on human prostate tissue and biofluids and to consolidate trustworthy data on the role of miRNA in the occurrence and progression of PCa, with a delineation of differentially expressed miRNAs and an analysis of their association with PCa prognosis, progression to CRPC and metastatic disease, as well as their correlation with response to chemotherapy and hormonal therapy. Changes in circulating miRNAs may represent potentially useful non-invasive biomarkers for PCa diagnosis, staging and prediction of outcome.