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

INTRODUCTION: MicroRNAs (miRNA) are small (approximately 17 to 25 nucleotides 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 suffering from BC (histopathologically confirmed), in which 20 patients were diagnosed with muscle invasive BC (INBC) and 40 patients with non-muscle invasive BC (NINBC). The control group consisted of 20 samples of normal urothelium, which did not show any cancerous changes during histopathological examination. We assessed the expression of microRNA, using real-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-Whitney 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 significantly altered in bladder cancer samples and useful as diagnostic markers.