Bmi-1 induces NF-kappaB transcriptional activity. A, Luciferase reporter assay of NF-κB transcriptional activity in vector-control, Bmi-1 overexpressing (Bmi-1) and Bmi-1 silenced glioma cells (Bmi-1-RNAi). B, Real-time PCR analysis of NF-κB-regulated gene expression in vector-control, Bmi-1 overexpressing and Bmi-1 silenced glioma cells; GAPDH was used as the control gene. C, Left, schematic illustration of luciferase reporter gene construction using cloned fragments of the human MMP-9 promoter. Right, transactivation activity of luciferase reporter genes driven by MMP-9 promoter fragments (as indicated on the left) in vector-control, Bmi-1 overexpressing and Bmi-1 silenced glioma cells. Luciferase activity was normalized to Renilla luciferase activity. Vector: pMSCV-vector, RNAi-Vector: pSuper-retro-puro-vector. Error bars represent the mean ± SD of three independent experiments; * P < 0.05, ** P < 0.01.