MicroRNA-590 is an EMT-suppressive microRNA involved in the TGFβ signaling pathway

Over the last few decades, the epithelial-to-mesenchymal transition (EMT) has been identified as being involved in a number of aspects of physiological processes and various pathological events, including embryonic development and renal fibrosis. Transforming growth factor-beta receptor 2 (TGF beta R2) is a widely studied gene, which fulfils a vital role in the TGF beta signaling pathway and exerts a crucial function in the progression of EMT. Previous studies demonstrated that the dysregulation of microRNAs (miRNAs) is considered to be associated with the EMT process. However, the precise functional involvement of miRNAs in EMT remains to be fully elucidated. In the present study, the level of miR-590 was decreased in an EMT model in vitro and in vivo. Furthermore, the overexpression of miR-590 inhibited EMT by upregulating the epithelial marker, E-cadherin, and downregulating the mesenchymal markers, laminin, alpha-smooth muscle actin (alpha-SMA) and collagen, in the human kidney 2 (HK2) cell line. Furthermore, TGF beta R2 was negatively regulated by miR-590. In addition, performing a knockdown of TGF beta R2 with small-interfering RNA had an effect similar to miR-590 on EMT in the HK2 cell line, whereas the transfection of pCMV-tag2B-TGF beta R2 reversed the effect of miR-590 on EMT in HK2 cells. Taken together, the present study demonstrated that miR-590 is a novel EMT-suppressive microRNA, which targets TGF beta R2.