FoxO3a mediates glioma cell invasion by regulating MMP9 expression

The role of FoxO3a in glioma progression is poorly defined. Herein, we show that silencing FoxO3a in U251 cells leads to decreased invasive migration and proliferation, while ectopic expression of FoxO3a in U87 cells with weak endogenous FoxO3a protein levels enhances invasion and proliferation. To further investigate the mechanism by which FoxO3a promotes invasion, we detected key members of the matrix metalloproteinases (MMPs) that are associated with invasion. Our findings showed that, among these MMP members, only FoxO3a induced MMP9 expression, and MMP9 overexpression reversed the effect that silencing FoxO3a had on the attenuation of cell invasion. Taken together, these data link FoxO3a to the promotion of metastasis in glioma cells.