MicroRNA-7 suppresses human colon cancer invasion and proliferation by targeting the expression of focal adhesion kinase

Abstract

Previous studies have demonstrated that microRNA (miRNA) are essential in tumor development and invasion. The close association between focal adhesion kinase (FAK) and colon cancer (CC) has been previously reported. miRNA-7 (miR-7) inhibits the translation of FAK protein. Therefore, the present study aimed to assess the underlying molecular mechanism of miR-7 in human CC cell lines, to provide a novel therapeutic biomarker of CC in the future. The present study detected the expression of miR-7 in 60 CC tissues by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The association between the expression of miR-7 and clinical pathological factors was analyzed. Overexpression/underexpression of miR-7 were established by transfecting miR-7mimics/inhibitors into HCT-8 and Caco-2 cells. The transfected CC cell lines were used in cell viability and scratching assays. The regulation of FAK by miR-7 was analyzed by western blotting and RT-qPCR. It was demonstrated that the expression of miR-7 negatively correlated with lymph node metastasis and tumor node metastasis staging in CC (P<0.05). Inhibition of miR-7 led to an accelerated ability of proliferation and migration in CC cell lines. Additionally, overexpression of miR-7 inhibited the proliferation and migration of CC cells. In addition, it was also observed that miR-7 regulated the proliferation and migration of CC by regulating the protein expression of FAK, therefore, regulating the expression of matrix metalloproteinase (MMP)-2 and MMP-9. miR-7 inhibited the proliferation and migration of CC cells by regulating FAK. These findings suggested that miR-7 may be a novel therapeutic target for CC.