miR-485-5p inhibits bladder cancer metastasis by targeting HMGA2

MicroRNA (miRNA or miR)-485 is a functional miRNA which has received much attention in recent years. However, little is known about the expression of miR-485 or the role it plays in bladder cancer [namely in metastasis and epithelial-mesenchymal transition (EMT)]. Thus, in the present study, we aimed to detect the expression of miR-485 in human bladder cancer tissues and bladder cancer cell lines, and to examine the effects of miR-485-5p on bladder cancer cell metastasis and EMT. We found that the expression of miR-485-5p was downregulated in the human bladder cancer tissues and different bladder cancer cell lines compared with the normal tissues and cell lines, as demonstrated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We enforced the expression of miR-485-5p in T24 cells and inhibited the expression of miR-485-5p in SW780 cells by transfection with miR-485-5p mimic or miR-485-5p inhibitor, respectively. The ectopic expression of miR-485-5p was shown to inhibit cell metastasis and EMT, whereas the inhibition of miR-485-5p expression promoted cell metastasis and EMT, as shown by Transwell-Matrigel assay, cell adhesion assay and western blot analysis. Furthermore, a luciferase reporter assay revealed that high mobility group AT-hook 2 (HMGA2) was a direct target of miR-485-5p and that the overexpression of HMGA2 reversed the effects of miR-485-5p on cell metastasis and EMT. In conclusion and to the very best of our knowledge, the present study, for the first time, identified miR-485-5p as a suppressive miRNA in human bladder cancer, and demonstrated that miR-485-5p inhibits cell metastasis and EMT at least partly through the suppression of HMGA2 expression.