Researchers from Oslo University Hospital set out to identify microRNAs in urinary exosomes that are differently expressed in prostate cancer patients and healthy donors. For this purpose, RNA was extracted from urinary exosomes from 20 prostate cancer patients and 9 healthy males and the microRNAs were analyzed by next generation sequencing. Interestingly, 5 microRNAs – miR-196a-5p, miR-34a-5p, miR-143-3p, miR-501-3p and miR-92a-1-5p – were significantly downregulated in exosomes from prostate cancer patients. Furthermore, RT-qPCR analysis of an independent cohort of 28 prostate cancer patients and 19 healthy males confirmed that miR-196a-5p and miR-501-3p were downregulated in prostate cancer samples. These results suggest that specific microRNAs in urinary exosomes might serve as non-invasive biomarkers for prostate cancer. In particular, miR-196a-5p and miR-501-3p are promising biomarkers that need to be further studied in large patient cohorts.
RT-qPCR analysis of selected miRNAs
a. miR-196a-5p and b. miR-501-3p were analyzed in 19 healthy controls and 28 PCa patients. The data was normalized to the average of three reference genes (miR-10b-5p, let-7b-5p and U6 snRNA). *P < 0.05; **P < 0.01 versus control group. c, d. ROC curves for miR-196a-5p (AUC = 0.73, 95% CI 0.56 to 0.89) and miR-501-3p (AUC = 0.69, 95% CI 0.52 to 0.85). AUC, area under the curve; CI, confidence interval