Purpose: To investigate the regulatory mechanism of miR-218 in human hepatocellular carcinoma (HCC).
Methods: qPCR was used to compare the expression levels miR-218 among six hepatocellular carcinoma cell lines and normal liver tissues. After transfecting MHCC97L cells with either miR-218 mimics or miR-218 inhibitor, western blotting was used to examine the expressing patterns of cyclinD1, p21, and PTEN/AKT/PI3K signaling pathway-related proteins. MTT and colony forming assay was used to assess the capability of cell proliferation. Bioinformatic method was applied to predict the binding of miR-218 on HoxA10, and western blotting was used to examine the modulatory effect of miR-218 AND HoxA10 on PTEN/AKT/PI3K pathway in HCC.
Results: The expression levels of miR-218 were frequently lower in HCC cell lines than in normal liver tissues. Over-expression of miR-218 in HCC cells significantly decreased cell proliferation whereas inhibiting miR-218 promoted cancer cell proliferation. Western blotting analysis demonstrated that tumorigenesis related protein cyclin D1 and p21, as well as PTEN/AKT/PI3K signaling pathways were actively modulated by miR-218 in HCC cells. The expression of endogenous HoxA10 was also down-regulated by miR-218 over-expression, and silencing HoxA10 directly activated PTEN in HCC cells.
Conclusion: Modulation of miR-218 actively affected HCC cancer cell development. The regulatory mechanism of miR-218 in HCC cells was acting through PTEN/AKT/PI3K pathway and possibly associated with HoxA10.
Keywords: HoxA10; PTEN; hepatocellular carcinoma; miR-218.