Identification of miR‑30b 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, miR‑30b has been demonstrated to be deregulated in certain types of cancer, including lung, colorectal and gastric cancer. Previous studies of miR‑30b in renal clear cell carcinoma demonstrated that the expression level of miR‑30b was associated with distant metastasis. However, the function of miR‑30b in renal cell carcinoma (RCC) remained to be elucidated. In the present study, the expression of miR‑30b in 31 paired RCC tissues from four cell lines (786‑O, 769‑P, ACHN and 293T) was detected by reverse transcription‑quantitative polymerase chain reaction. In addition, the effect of miR‑30b on cell proliferation in RCC cells was also determined using MTT and Cell Counting Kit‑8 assay analyses. Furthermore, the function of miR‑30b in cell migration and invasion was determined by wound scratch and Transwell assays. Flow cytometry was also performed to quantify the effect of miR‑30b on cell apoptosis. The results of the current study indicated that miR‑30b 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 miR‑30b as observed in other types of cancer. miR‑30b is associated with RCC cell proliferation, invasion, migration and apoptosis, which indicated that miR‑30b acts as an oncogene in RCC. To the best of our knowledge, the present study is the first to demonstrate the upregulation of miR‑30b in RCC tissues and describe miR‑30b as an oncogene in RCC in the regulation of cell proliferation, migration, invasion and apoptosis. Further studies will define the target gene of miR‑30b in RCC and investigate the potential role of miR‑30b as a biomarker for RCC.