Non-invasive Prostate Cancer Detection by Measuring Expression Level of miR-21 and miR-214 in Urine

Background: Prostate cancer is the most prevalent cancer among men worldwide. Diagnosis in this cancer is primarily done, using aggressive methods such as biopsy. Laboratory methods, such as the measurement of prostate-specific antigen (PSA) in the blood, do not have high sensitivity and specificity. MicroRNAs (miRNAs), a group of diagnostic biomarkers, can diagnose diseases such as cancer. MicroRNA (miRNA) is a small, non-coding, single-stranded RNA with a length of 21 to 23 nucleotides. Objectives: This study was designed to investigate the changes in the expression level of miR-21 and miR-214 in the urine of patients with prostate cancer compared with healthy controls. Methods: A total of 70 urine samples from prostate cancer patients (32 metastatic and 38 non-metastatic) and 30 from healthy subjects with negative biopsy reports were collected. The expression level of miR-21 and miR-214 in the urine were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results: miR-21 showed a significant increase in expression (P = 0.003) and miR-214 showed a significant decrease in expression (P = 0.000) compared with the control group. The specificity, sensitivity, and area under the curve (AUC) were 100, 72.14, and 0.721% for combined panels of miR-21 and miR-214 and 63.33, 61.43, and 0.620%, respectively, for PSA. Conclusions: miR-21 and miR-214 showed significant change in expression in patients with prostate cancer compared with healthy subjects. It is hoped that, with further research, a combined panel of miR-21 and miR-214 can be used as a non-invasive method for detecting prostate cancer with higher sensitivity and specificity than the PSA test.