Virus encoded circulatory miRNAs for early detection of prostate cancer

BACKGROUND Prostate cancer (PCa) is the most commonly diagnosed cancer and kills about 28,000 American men annually. Although progress has been made in understanding the molecular features of different forms of the disease, PCa is considered incurable when it becomes resistant to standard therapies. Prostate specific antigen (PSA) test has been a gold standard of diagnosis for PCa, however, it can result in lead to the unnecessary biopsies and treatment of indolent cancers due to the low specificity. Thus, the limitations of PSA screening for PCa have prompted much focus on strategies how to enhance the accuracy of PSA for distinction between aggressive and indolent cancers. DISCUSSION Studies of miRNAs in PCa patients have suggested differentially expressed miRNAs between healthy controls and those with PCa, providing potential biomarker candidates using body fluids including urine and blood. Virus infection has been considered to associate with PCa incidence. Virus infected PCa cells may shed extracellular vesicles and communicate with neighboring cells, which were not infected yet, however, no mechanistic approaches were performed to understand the biology. The miRNAs composition in the shedding extracellular vesicles, and its role in PCa are completely undefined. In the near future, new insights to connect between the viral derived miRNAs and PCa progression might provide an opportunity to diagnose, risk prediction and therapeutic strategies. The goal of this debate article is to provide a short review on miRNAs, virus infection and viral encoded miRNAs in PCa, with a primary focus on circulating miRNAs as potential non-invasive biomarkers for PCa patients.