Detection of urinary cell-free miR-210 as a potential tool of liquid biopsy for clear cell renal cell carcinoma.

BACKGROUND: Recent findings show that cell-free miRNAs are stable in biological fluid. Urine provides an alternative to blood serum or plasma as a potential source of tumor biomarkers. MiR-210 is proven to be overexpressed in patients with a clear cell renal cell carcinoma (ccRCC). The purpose of this pilot study was to examine the urinary cell-free miR-210 as a potential tool of liquid biopsy for ccRCC.

METHODS: Overall, 75 patients with a ccRCC and 45 control subjects without a cancer were included in this study. Urine samples were centrifuged twice and the cell-free urine supernanants were stored in -80°C until use. A total of 350µl cell-free urine was used for the extraction of total RNA. The expression levels of these miRNAs were performed by using quantitative RT-PCR.

RESULTS: The level of urinary cell-free miR-210 was significantly higher in patients with ccRCC than in control subjects (P<0.001). The urinary cell-free miR-210 yielded the areas under the receiver operating characteristics curve of 0.76 in discriminating the patients with ccRCC from the control subjects with a sensitivity of 57.8% and a specificity of 80.0%. Moreover, the expression level of urinary cell-free miRNA-210 was significantly decreased in the patients a week after surgery (P<0.001).

CONCLUSION: Urinary cell-free miR-210 may be used as a potential tool of liquid biopsy for ccRCC diagnosis. Further studies are needed to confirm our results.