Urinary-derived extracellular vesicle microRNAs as non-invasive diagnostic biomarkers for early-stage renal cell carcinoma

Background and aims: The potential of urinary-derived extracellular vesicle (uEV) microRNAs (miRNAs) as noninvasive molecular biomarkers for identifying early-stage renal cell carcinoma (RCC) patients is rarely explored. The present study aims to explore the possibility of uEV miRNAs as novel molecular biomarkers for distinguishing early-stage RCC. Materials and methods: uEVs were extracted by ExoQuick-TCTM kit and miRNA concentrations were measured by RT-qPCR. ROC curves and bioinformatics analysis were employed to predict the diagnostic efficacy and regulatory mechanisms of dysregulated miRNAs. Results: Through a multiphase case-control study on uEV miRNAs screening, training, and validation in RCC cells (ACHN, Caki-1) and control cells (HK-2) and in uEVs of 125 RCC patients and 128 age- and sex-matched controls, we successfully identified four uEVs miRNAs (miR-135b-5p, miR-196b-5p, miR-200c-3p, and miR-203a-3p) were significantly and stably upregulated in RCC in vitro and in vivo. When adjusted with estimated glomerular filtration rate (eGFR), the AUC of the three-uEV miRNA panel (miR-135b-5p, miR-200c-3p, and miR-203a-3p) was 0.785 (95 % CI = 0.729-0.842, P < 0.0001) for discriminating RCC patients from controls. Notably, this panel exhibited similar performance in distinguishing early-stage (stage I) RCC patients, with an AUC of 0.786 (95 %CI = 0.727-0.844, P < 0.0001). Bioinformatics analysis predicted that candidate miRNAs were involved in cancer progressing. Conclusion: Our study identified a four uEV miRNAs panel (miR-135b-5p, miR-196b-5p, miR-200c-3p, and miR203a-3p) may serve as an auxiliary noninvasive indication of early-stage RCC.