Clinical value of microRNA-19a-3p and microRNA-99a-5p in bladder cancer

Introduction: MicroRNAs (miRNA) are small (approximately 17 to 25 nucle-otides in length), single stranded, non-coding RNAs that play an important role in the control of gene expression at the post-transcriptional stage, by inhibiting protein translation or promoting mRNA degradation. The main aim of the study was to evaluate the clinical utility of the tested markers (miRNAs 19a-3p and 99a-5p), which might be important in the diagnostics of non-invasive bladder cancer (BC).Material and methods: The study involved a group of 60 patients suffer-ing from BC (histopathologically confirmed), in which 20 patients were di-agnosed with muscle invasive BC (INBC) and 40 patients with non-muscle invasive BC (NI NBC). The control group consisted of 20 samples of normal urothelium, which did not show any cancerous changes during histopatho-logical examination. We assessed the expression of microRNA, using re-al-time PCR and the miRCURY LNA Universal RT microRNA PCR Kit by Exiqon, Denmark. Results: Reduced expression of both analyzed markers was observed in most cases: miR-19a-3p in 51.8% and miR-99a-5p in 65.5% (as follows Mann -Whit-ney U test p < 0.000001 and Student's t test p = 0.034262). Moreover, miR-19a-3p in our tested group was useful to differentiate between low and high grade disease in non-invasive stages (t test p = 0.0315435). Furthermore, miR-19a-3p and miR-99a-5p were able to discriminate patients in low grade for groups with or without recurrence.Conclusions: Our data indicated that miR-19a-3p and miR-99a-5p were sig-nificantly altered in bladder cancer samples and useful as diagnostic markers.