Downregulation of microRNA-196a inhibits human liver cancer cell proliferation and invasion by targeting FOXO1

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and effective therapy for human liver cancer remains a difficult clinical concern. Researchers have demonstrated that microRNAs play important roles in the tumorigenesis and tumor progression of human liver cancer; therefore, regulation of microRNAs may be a new strategy for HCC therapy. MicroRNA-196a (miR196a) has been reported to be overexpressed in many types of cancers. However, the regulatory effects of miR-196a in human liver cancer are not fully understood. In the present study, we found that miR-196a was overexpressed in human liver cancer cells compared to that observed in normal liver cells. MTT and colony formation assays indicated that downregulation of miR-196a inhibited liver cancer cell proliferation which was due to the induction of cell apoptosis. A mouse model demonstrated that downregulation of miR-196a also inhibited human liver cancer cell migration and invasion in vivo. Further study indicated that FOXO1 is a direct target of miR-196a, and inhibition of FOXO1 promoted human liver cancer cell growth. Taken together, the present study demonstrated that the expression of miR-196a in human liver cancer cells was upregulated; downregulation of miR-196a regulated human liver cancer cell biological functions which could benefit the clinical therapy of human liver cancer in the future.