MicroRNA- 130b suppresses migration and invasion of colorectal cancer cells through downregulation of integrin β1 [corrected]

MicroRNA 130b (miR-130b) is significantly dysregulated in various human tumor types. In this study, using a microarray assay, we characterized the upregulation of miR-130b expression in colorectal cancer (CRC) specimens. However, there is limited knowledge about the roles of aberrant miR-130b expression in CRC. Our studies in CRC cells demonstrated that miR-130b significantly decreases cell migration and invasion, but it has no evidently effects on cell proliferation and apoptosis. In the overexpression miR-130b CRC cells and the CRC specimens, we observed a decreased level of integrin β1 protein, which is considered as a key molecule involved in cell motility. The targeting of the 3'-UTR region of integrin β1 gene by miR-130b was revealed using a luciferase reporter assay. The regulation of integrin β1 by miR-130b was further shown using the miR-130b mimics and the inhibitor of miR-130b. The impaired motility of the miR-130b overexpression cells is recovered partly by the expression of integrin β1 lacking the 3'-UTR. Additionally, the knockdown of integrin β1 also gives rise to a decrease in cell migration and invasion, which is similar to the impeded motility due to overexpression of miR-130b in CRC cells. Furthermore, the inverse expressions of miR-130b and integrin β1 were observed in CRC specimens. In summary, these data demonstrate that miR-130b downregulates its target-integrin β1, leading to the impaired migration and invasion of CRC cells.