AIM: To verify the role of enhancing or suppressing the expression of glutathione peroxidase 1 (GPx1) in the growth, migration and invasion of glioblastoma multiforme cell lines U87MG and U118MG.METHODS:U87MG and U118MG cell lines were transfected with the vector containing specific siRNA or pcDNA3.1 recombinant plas-mid both targeting GPx1.The mRNA and protein expression levels of GPx1 were detected by real-time PCR and Western blotting.MTS assay was applied for determining the cell activity.The abilities of migration and invasion were examined by Transwell assay.RESULTS:Compared with blank control group and negative group, the inhibitory rate of the cell activity in U87MG cells in siRNA group was significantly reduced by 25.9%, 35.7%and 34.8%at 24 h, 48 h and 72 h, respec-tively (P<0.05).In contrast, the cell activity of U118MG cells in pcDNA3.1-GPx1 group was significantly increased by 22.7%, 45.8%and 39.8%at 24 h, 48 h and 72 h, respectively ( P<0.05) .In siRNA group, the inhibitory rate of mi-gration in U87MG cells was 41.6%±8.2%and the invasion was 41.6%±8.2%compared with blank control group and negative group (P<0.05).The cell migration and invasion rates of the U118MG cells in pcDNA-GPx1 group were in-creased by 55.8%±9.8% and 60.8% ±9.2%, respectively, compared with blank control group and negative group (P<0.05).CONCLUSION:The down-regulation of GPx1 by specific siRNA reduces the capability of cell growth, mi-gration and invasion of U87MG cells, while up-regulation of GPx1 by pcDNA3.1-GPx1 increases the capability of cell growth, migration and invasion of U118MG cells.