Targeting effect of microRNA on CD133 and its impact analysis on proliferation and invasion of glioma cells.

MiR-200b, a member of the microRNA-200 family, has been identified to be capable of suppressing glioma cell growth through targeting CREB1 or CD133. However, whether miR-200b affects the biological behavior (proliferation, invasion, and migration) of glioma cells is poorly understood. The aim of this study was to evaluate the effect of miR-200b on the biological behavior of glioma cells in vitro. MiRNA-200b mimics, miRNA-200b inhibitor, and mimic control were transfected into conventionally cultured glioma U251 cells, followed by measuring the expression of miR-200b and CD133 in transfected cells by RT-PCR; effect of miR-200b on CD133 mRNA 3'-UTR luciferase activity by luciferase reporter assay; proliferation activity of transfected U251 cells by MTT method; and changes in U251 cell invasion and migration by Transwell method after transfection. Compared to that in the miRNA-200b inhibitor, mimic control, and blank control groups, miRNA-200b expression was significantly increased and CD133 mRNA expression was significantly decreased in the mimic miRNA-200b group in a time-dependent manner (P < 0.05). Meanwhile, dual luciferase reporter assay showed that miR-200b could inhibit CD133 activity through binding to the 3'-UTR of CD133 mRNA (P < 0.05). Furthermore, the proliferation activity and invasion and migration abilities of U251 cells transfected with miRNA-200b mimic were significantly decreased (P < 0.05). In conclusion, overexpression of miR-200b inhibited the proliferation, invasion, and migration of glioma cells possibly through targeting CD133.