The Potential of MicroRNAs as Prostate Cancer Biomarkers

Context Short noncoding RNAs known as microRNAs (miRNAs) control protein expression through the degradation of RNA or the inhibition of protein translation. The miRNAs influence a wide range of biologic processes and are often deregulated in cancer. This family of small RNAs constitutes potentially valuable markers for the diagnosis, prognosis, and therapeutic choices in prostate cancer (PCa) patients, as well as potential drugs (miRNA mimics) or drug targets (anti-miRNAs) in PCa management. Objective To review the currently available data on miRNAs as biomarkers in PCa and as possible tools for early detection and prognosis. Evidence acquisition A systematic review was performed searching the PubMed database for articles in English using a combination of the following terms: microRNA, miRNA, cancer, prostate cancer, miRNA profiling, diagnosis, prognosis, therapy response, and predictive marker. Evidence synthesis We summarize the existing literature regarding the profiling of miRNA in PCa detection, prognosis, and response to therapy. The articles were reviewed with the main goal of finding a common recommendation that could be translated from bench to bedside in future clinical practice. Conclusions The miRNAs are important regulators of biologic processes in PCa progression. A common expression profile characterizing each tumor subtype and stage has still not been identified for PCa, probably due to molecular heterogeneity as well as differences in study design and patient selection. Large-scale studies that should provide additional important information are still missing. Further studies, based on common clinical parameters and guidelines, are necessary to validate the translational potential of miRNAs in PCa clinical management. Such common signatures are promising in the field and emerge as potential biomarkers. Patient summary The literature shows that microRNAs hold potential as novel biomarkers that could aid prostate cancer management, but additional studies with larger patient cohorts and common guidelines are necessary before clinical implementation.