miR-625-3p promotes migration and invasion and reduces apoptosis of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common malignancy, yet, the mechanisms underlying tumorigenesis remain unclear. Several miRNAs have been implicated in the development of RCC previously via regulation of target gene expression. As miR-625-3p has recently been identified to play a role in development of other malignancies and is reportedly upregulated in ccRCC, we sought to investigate the role of this miRNA in the progression of ccRCC. Analysis of 30 paired fresh ccRCC tissues and adjacent normal renal tissues revealed that the expression of miR-625-3p was increased in ccRCC tissues compared to normal tissues. Subsequently, in 136 formalin-fixed paraffin-embedded ccRCC tissues, the increased miR-625-3p expression was correlated with poor prognosis for ccRCC patients. The diagnostic value of miR-625-3p was identified in 50 ccRCC patients and 74 healthy controls by ROC curve. miR-625-3p was decreased in serum of ccRCC patients compared to healthy individuals. miR-625-3p could serve as a promising serum biomarker for yielding an area under the receiver operating characteristic curve of 0.792 with 70.3% sensitivity and 80.0% specificity in discriminating ccRCC from healthy individuals. Using in vitro functional assays, we found that overexpression of miR-625-3p promoted migration and invasion of ccRCC cells but reduced ccRCC cell apoptosis. Inhibition of miR-625-3p, on the other hand, exerted the opposite effects. Bioinformatic analyses indicated that predicted gene targets of miR-625-3p are correlated with lower overall survival of ccRCC patients. Together, these findings demonstrate that miR-625-3p promotes ccRCC migration and invasion and reduces apoptosis, providing a prognostic marker for survival and a potential diagnostic and therapeutic target against ccRCC.