Urinary extracellular vesicles as potential biomarkers for urologic cancers: An overview of current methods and advances

Abstract

Urologic cancers are a heterogeneous group of tumors, some of which have poor progno-sis. This is partly due to the unavailability of specific and sensitive diagnostic techniques and monitoring tests, ideally non-or minimally invasive. Hence, liquid biopsies are promising tools that have been gaining significant attention over the last decade. Among the different classes of bi-omarkers that can be isolated from biofluids, urinary extracellular vesicles (uEVs) are a promising low-invasive source of biomarkers, with the potential to improve cancer diagnosis and disease man-agement. Different techniques have been developed to isolate and characterize the cargo of these vesicles; however, no consensus has been reached, challenging the comparison among studies. This results in a vast number of studies portraying an extensive list of uEV-derived candidate biomarkers for urologic cancers, with the potential to improve clinical outcome; however, without significant validation. Herein, we review the current published research on miRNA and protein-derived uEV for prostate, bladder and kidney cancers, focusing on different uEV isolation methods, and its implications for biomarker studies.