Emerging role of secreted miR-210-3p as potential biomarker for clear cell Renal Cell Carcinoma metastasis

BACKGROUND: MicroRNAs (miRNAs) are emerging as promising molecules in the diagnosis, prognosis and treatment of urological tumours. Recently, our group performed two independent studies highlighting that miR-210-3p may be a useful biomarker not only for diagnosis but also for post-surgery clear cell Renal Cell Carcinoma (ccRCC) management. OBJECTIVE: The aim of this study is to further explore the effectiveness of miRNA as non-invasive biomarker for clinical outcomes and ccRCC response to the treatment. METHODS: We analyzed miR-210-3p levels in neoplastic and healthy tissue and in urine specimens collected at surgery and during follow-up of 21 ccRCC patients by RTqPCR. RESULTS: Firstly, we confirmed that the expression of miR-210-3p was upregulated in tumor tissues and in urine samples of analyzed cohort. Of note is that miR-210-3p expression was significantly reduced in urine samples from disease-free patients during follow-up (from 3 to 12 months) compared to the baseline levels observed at the time of surgery. In a small subgroup of patients presenting metastatic progression (such as bone, intestinal or lung metastasis), the urine levels of miR-210-3p correlated with responsiveness to the therapy. CONCLUSIONS: This pilot study highlights the relevance of secreted miR-210-3p as powerful non-invasive prognostic and predictive biomarker for the evaluation of clinical outcomes and treatment response during ccRCC follow up.