MicroRNA-217, down-regulated in clear cell renal cell carcinoma and associated with lower survival, suppresses cell proliferation and migration

Aberrantly expressed microRNAs (miRNAs) are frequently correlated with a variety of human cancers, including clear cell renal cell carcinoma (ccRCC). In this study, we determined the expression patterns of miR-217 in ccRCC, and tested its effect on cancer cell proliferation and migration. The expression levels of miR-217 were determined in 54 ccRCC samples using Real-Time qPCR. 786-O and ACHN cells were transfected with miR-217 mimics or miRNA mimics control. Cell proliferation and migration were evaluated by MTT assay and scratch-wound assay, respectively. We found that miR-217 was down-regulated in ccRCC compared to paired normal tissue. Lower miR-217 expression levels were associated with higher tumor grade and stage. All patients with high miR-217 expression survived 5 years, while with low miR-217 expression, only 40% survived. Cell proliferation inhibition and decreased motility were observed in cells transfected with the miR-217 mimics. In conclusion, miR-217 plays a tumor suppressor role in ccRCC.