MicroRNA-145 Promotes the Phenotype of Human Glioblastoma Cells Selected for Invasion.

Abstract

BACKGROUND/AIM: Novel treatment strategies aiming to eliminate or attenuate the invasive phenotype of glioblastoma multiforme (GBM), the most common and aggressive primary brain tumor, could offer a profound therapeutic benefit to patients. We previously demonstrated one method to create invasive sub-populations of GBM cells (IM3 cells) and a positive regulatory role for the miR-143/-145 locus in enhancing the invasion of GBM cells. Herein, we investigated the correlation between miR-145 and srGAP1 (SLIT-ROBO Rho GTPase-activating protein1) that is purported to be a target of miR-145 and involved in migration and invasion. MATERIALS AND METHODS: IM3 cells were created by a serial selection by using Boyden chambers®. Antisense-miR-145 was transfected into IM3 cells by using lipofectamine 2000. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) and western blot were employed to analyze the expression of srGAP1. RESULTS: The invasiveness of U87-IM3 and U251-IM3 is attenuated by transfection of antisense miR-145. In addition, srGAP1 was down-regulated in U87-IM3 and U251-IM3 cells compared to parental cells. CONCLUSION: The elevated miR-145 present in invasive glioblastoma cells (IM3 cells) targets and down-regulated srGAP1, thereby allowing downstream G-proteins to remain in their active state and promote the observed invasive phenotype.