MicroRNA-19a targets tissue factor to inhibit colon cancer cells migration and invasion

The over-expression of tissue factor (TF) and its roles in colon cancer progression have attracted much attention. However, the mechanisms regulating TF expression have not yet been shown in detail. In this study, we over-expressed miR-19a, miR20a and miR-106b in colon cancer cells, and evaluated their impact on TF expression and cellular function. We provide evidence demonstrating that miR-19a inhibited TF expression in vitro. Luciferase reporter assay confirmed that TF was a direct target of miR-19a because the miR-19a mediated repression of luciferase activity was abolished by mutation of the putative binding site. Moreover, miR-19a suppressed colon cancer cell migration and invasion. This effect was due to the indirect down-regulation of matrix metalloproteinase 9. Finally, we investigated the relevance of TF and miR-19a expression in a total of 48 paired colon cancer samples and revealed that miR-19a was inversely correlated with TF expression in stages I and II cases. Therefore, our results suggested that miR-19a was capable of suppressing TF expression in vitro and inhibiting cell migration and invasion. Although it was not the unique mechanism responsible for the expression of TF in vivo, miR-19a was inversely correlated with TF expression in early stage colon cancer patients.