The translational potential of microRNAs as biofluid markers of urological tumours

MicroRNAs (miRNAs) are secreted by cells in vesicles, bound in a ribonucleoprotein complex or as free molecules. These miRNA secretion pathways are dysregulated in cancer, making miRNAs attractive candidate molecules for liquid biopsies. A number of studies have investigated the regulation of miRNA secretion into blood and urine and suggested that miRNAs are noninvasive diagnostic, prognostic and surveillance markers in urological carcinomas, and research in this area has increased over the past 5 years. However, methodological and analytical pitfalls exist and require addressing to enable future translation of the laboratory findings regarding miRNAs as biomarkers into clinical practice in bladder cancer, kidney cancer, prostate cancer and testicular cancer.