miR-21-5p, miR-141-3p, and miR-205-5p levels in urine-promising biomarkers for the identification of prostate and bladder cancer

Early detection of cancers improves patients' survival and decreases the treatment cost. Unfortunately, the current methods for diagnosis of bladder and prostate cancers, two most common urothelial malignancies, suffer from a low sensitivity and specificity. MicroRNAs, as a group of endogenously produced non-coding RNAs, regulate gene expression and their expression is observed to be altered in many cancers and cancer progression phenomena. The remarkable stability of microRNAs in biofluids and their unique expression pattern in different pathological conditions make them an appealing, noninvasive diagnostic method in cancer diagnosis. Our objective is to identify microRNAs as biomarkers in urine samples of bladder and prostate cancers to improve the existing diagnostic methods in this field.In this study, urine samples from 110 men with either bladder (n = 45) or prostate (n = 23) cancer, benign prostatic hyperplasia (n = 22) and healthy controls (n = 20) were collected. qPCR was used to evaluate the expression level of miR-21-5p, miR-141-3p, and miR-205-5p in these samples. The sensitivity and specificity of these microRNAs were determined using ROC curve analysis.The analysis of the data revealed that miR-21-5p, miR-141-3p, and miR-205-5p are differentially expressed in urine of bladder and prostate cancer patients. All these three microRNAs were upregulated in these samples and they were also able to differentiate benign prostatic hyperplasia from malignant cases. The statistical analyses revealed a good specificity for each individual microRNA.The results show that these three urine-based microRNAs might be a good choice to implement a specific and non-invasive diagnostic tool for bladder and prostate cancer. The expression pattern of all three microRNAs was particularly useful to distinguish benign and invasive tumors in prostate cases. From the patients' perspective the improvement of the diagnostic situation is awaited eagerly.