MicroRNA-124 regulates TGF-α-induced epithelial-mesenchymal transition in human prostate cancer cells

Transforming growth factor-α (TGF-α) is upregulated in advanced stages of prostate cancer and strongly correlated with metastasis. However, the effect of TGF-α on epithelial-mesenchymal transition (EMT) in prostate cancer and the underlying mechanisms remain unclear. Recently, microRNAs have emerged as new regulators of EMT. This study found that treatment of DU145 cells with TGF-α suppressed the expression of epithelial marker E-cadherin and increased the expression of mesenchymal marker Vimentin as well as changed the cell morphology from cobblestone shape to spindle shape. The level of miR-124 was downregulated by TGF-α in several different cancer cell lines. Enforced expression of miR-124 abolished TGF-α-induced EMT. Slug was proven to be a target of miR-124 and mediated the inhibitory effect of miR-124 on TGF-α-induced EMT. Furthermore, overexpression of miR-124 reduced the migratory and invasive capacity of TGF-α-treated DU145 cells. In conclusion, our findings suggest that miR-124 inhibits TGF-α-induced EMT in DU145 cells by targeting Slug. Thus, miR-124 may be a potential target for prostate cancer therapeutic intervention.