Expression of microRNAs in the urine of patients with bladder cancer

We quantified the urine sediment and supernatant levels of microRNA (miRNA) targets related to epithelial-mesenchymal transition in 51 patients with bladder cancer and in 24 controls. We found that patients with bladder cancer had depressed levels of the miR-200 family, miR-192, and miR-155 in urinary sediment. The urinary level of these miRNAs may be developed as noninvasive markers for bladder cancer.

MicroRNAs (miRNA) have been implicated to play an important role in the pathogenesis of a variety of cancers. We studied the levels of miRNAs related to epithelial-mesenchymal transition (EMT) in the urine of patients with bladder cancer.

The expression of the miR-200 family, miR-205, miR-192, miR-155, and miR-146a in the urine sediment and supernatant of 51 patients with bladder cancer and in 24 controls was determined by real-time quantitative polymerase chain reaction.

Compared with controls, the patients with bladder cancer had a lower expression of the miR-200 family, miR-192, and miR-155 in the urinary sediment; lower expression of miR-192; and higher expression of miR-155 in the urinary supernatant. The expression of the miR-200 family, miR-205, and miR-192 in the urine sediment significantly correlated with urinary expression of EMT markers, including zinc finger E-box-binding homeobox 1, vimentin, transforming growth factor β1, and Ras homolog gene family, member A. Furthermore, the levels of miR-200c and miR-141 in the urine sediment became normalized after surgery.

We found that the urinary miR-200 family, miR-155, miR-192, and miR-205 levels are depressed in patients with bladder cancer. The level of these miRNA targets in urine has the potential to be developed as noninvasive markers for bladder cancer.