Involvement of EGFR, ERK-1,2 and AKT-1,2 Activity on Human Glioma Cell Growth.

GBM (Glioblastoma multiforme) is the  most prevalent and lethal primary brain tumor. Gene therapy is one of the promising approaches and  involves the delivery of genetic therapeutic molecules for specific antitumour response/activity. miRNAs can regulate the cell biology functions including replication, cell growth, and apoptosis by regulating gene expression. In this study, we found that down-regulation of miR-4731 expression occurred in GBM cells. We further determined that miR-4731 behaved as a tumor suppressor by inhibiting GBM cell proliferation. We further investigated the molecular mechanisms of miR-4731 and EGFR, ERK-1,2 and AKT-1,2 in GBM cell lines U87 and U251. The in vitro ectopic expression of miR-4731 affected cell proliferation, migration, and invasion of U87 and U251 cells. Luciferase reporter assays validated that miR-4731 targeted the 3'-untranslated region (3'-UTR) of EGFR. In conclusions, we identified that miR-4731 plays a tumor suppressor role in GBM cell proliferation and migration by targeting EGFR expression, and miR-4731 may act as a novel biomarker for early diagnosis or therapeutic target of GBM.