MicroRNAs: a novel non-invasive biomarker for patients with urological malignancies.

MicroRNAs are small non-coding RNA molecules which do not code for proteins, but control the expression of a significant proportion of the genome. The microRNA expression differences of normal and malignant tissue, as well as the differences in various tumor entities qualify this RNA species as biomarker for cancer patients. The detection of microRNAs in various bodily fluids stimulated research, and it was demonstrated for most human malignancies that tumorassociated microRNAs are detectable in patients circulation, thereby providing diagnostic and/or prognostic information.