Expression of microRNAs in the urine of patients with bladder cancer

Abstract

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.

Background: 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.

Method: 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.

Results: 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.

Conclusion: 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.