Overexpression of miR-145 in U87 cells reduces glioma cell malignant phenotype and promotes survival after in vivo implantation.

In the present study, we sought to elucidate the effect of miR-145 on glioma cell progression and its mechanisms of action. We examined the effects of miR-145 on proliferation and invasion of U87 glioma cells and on capillary tube formation. Our data show that restoration of miR-145 in U87 glioma cells significantly reduced their in vitro proliferation, invasion and angiogenesis. However, decreased miR-145 expression promoted U87 glioma cell proliferation, invasion and angiogenesis, and reduced-expression of miR-145 increased ADAM17 and EGFR expression in U87 cells. Overexpression of miR-145 reduced ADAM17 and EGFR expression. VEGF secretion and VEGF expression were decreased by increased miR-145 expression in U87 cells and were reversed by miR-145 downregulation in vitro. Nude mice with intracerebral implantation of U87 overexpressing miR-145 cells exhibited significantly reduced tumor growth and promoted survival compared with control groups. Taken together, these results suggest a role for miR-145 as a tumor suppressor which inhibits glioma cell proliferation, invasion and angiogenesis in vitro and reduces glioma growth in vivo.