Identification of miR­30b as an oncogene in renal cell carcinoma.

microRNAs (miRs) have been investigated as a novel class of regulators of cellular processes, including proliferation, apoptosis and metabolism. In particular, miR­30b has been demonstrated to be deregulated in certain types of cancer, including lung, colorectal and gastric cancer. Previous studies of miR­30b in renal clear cell carcinoma demonstrated that the expression level of miR­30b was associated with distant metastasis. However, the function of miR­30b in renal cell carcinoma (RCC) remained to be elucidated. In the present study, the expression of miR­30b in 31 paired RCC tissues from four cell lines (786­O, 769­P, ACHN and 293T) was detected by reverse transcription­quantitative polymerase chain reaction. In addition, the effect of miR­30b on cell proliferation in RCC cells was also determined using MTT and Cell Counting Kit­8 assay analyses. Furthermore, the function of miR­30b in cell migration and invasion was determined by wound scratch and Transwell assays. Flow cytometry was also performed to quantify the effect of miR­30b on cell apoptosis. The results of the current study indicated that miR­30b was upregulated in RCC tissues from affected cell lines when compared with adjacent normal tissues and a normal kidney cell line, which is different to the downregulation of miR­30b as observed in other types of cancer. miR­30b is associated with RCC cell proliferation, invasion, migration and apoptosis, which indicated that miR­30b acts as an oncogene in RCC. To the best of our knowledge, the present study is the first to demonstrate the upregulation of miR­30b in RCC tissues and describe miR­30b as an oncogene in RCC in the regulation of cell proliferation, migration, invasion and apoptosis. Further studies will define the target gene of miR­30b in RCC and investigate the potential role of miR­30b as a biomarker for RCC.