MiR-570 Inhibited the Cell Proliferation and Invasion Through Directly Targeting B7-H1 in Hepatocellular Carcinoma

A recent study reported that miR-570 was the most important microRNA in the microRNA gene networks of alcoholic liver disease that has the potential of progressing to hepatocellular carcinoma. However, litter is known regarding the expression and specific function of miR-570 in the progression of hepatocellular carcinoma, especially its molecular mechanisms by which miR-570 exerts its functions and modulates the malignant phenotypes of hepatocellular carcinoma cells. Here, we observed that miR-570 was highly expressed in hepatocellular carcinoma cell lines (Bel-7404, Huh-7, and HepG2), while B7-H1 was lowly expressed, compared to nonmalignant cell line (L-02 and HL-7702). Transfection of miR-570 mimics or knockdown of B-H1 suppressed the expression of B7-H1, which promotes cell apoptosis and inhibits the cell proliferation and invasion. Using a dual-luciferase reporter system, we verified that B7-H1 is a direct target of miR-570. The overexpression of B7-H1 reversed the inhibition of proliferation and invasion by miR-570. In addition, miR-570 suppressed tumorigenicity in vivo. Hence, our observation confirmed that miR-570 works as proliferation and metastatic suppressor in hepatocellular carcinoma cells through directly targeting B7-H1 in hepatocellular carcinoma cell and rationally presents that miR-570 has the potential to be a useful clinical noninvasive diagnostics or predictive marker in human hepatocellular carcinoma.