To study the expression profiles of 5 microRNAs in tissue and serum of patients with clear cell renal cell cancer (ccRCC) and evaluate their diagnostic and prognostic potential.

We prospectively analyzed 30 patients of histologically proven ccRCC and collected 3 mL of serum preoperatively and small pieces of tumor and adjacent non–tumor renal tissue intraoperatively. Control serum samples were obtained from 15 patients of non–renal benign diseases. We analyzed 5 miRNAs—miR-34a, miR-141, miR-200c, miR-1233, and miR-21-2. Freshly collected samples were immediately frozen in liquid nitrogen and total RNA was extracted. cDNA was synthesized by reverse transcription, and quantitative polymerase chain reaction was performed to determine relative miRNA expression.

In the renal tissue and serum samples, 3 out of 5 miRNAs were differentially expressed; that is, the expression levels of miR-34a and miR-141 were significantly decreased, whereas that of miR-1233 was significantly increased. Serum miR-34a, miR-141, and miR-1233 were able to diagnose ccRCC with a sensitivity of 80.76%, 75%, and 93.33%, and specificity of 80%, 73.33%, and 100%, respectively, as compared to histopathology. Using a panel of 2 serum miRNAs (miR-141 and miR-1233) ccRCC can be diagnosed with 100% sensitivity and 73.3% specificity.

miRNAs are differentially expressed in serum of patients with ccRCC and can be used to diagnose ccRCC with high sensitivity and specificity. Diagnostic sensitivity can be further improved by using a panel of miRNAs and has the potential to serve as novel diagnostic markers of ccRCC.