Down-modulation of Bis reduces the invasive ability of glioma cells induced by TPA, through NF-κB mediated activation of MMP-9

Bcl-2 interacting cell death suppressor (Bis) has been shown to have anti-apoptotic and anti-stress functions. Recently, increased Bis expression was reported to correlate with glioma aggressiveness. Here, we investigated the effect of Bis knockdown on the acquisition of the invasive phenotype of A172 glioma cells, induced by 12-O-Tetradecanoylphorbol-3-acetate (TPA), using a Transwell assay. Bis knockdown resulted in a significant decrease in the migration and invasion of A172 cells. Furthermore, Bis knockdown notably decreased TPA-induced matrix metalloproteinase-9 (MMP-9) activity and mRNA expression, as measured by zymography and quantitative real time PCR, respectively. A luciferase reporter assay indicated that Bis suppression significantly down-regulated NF-kappa B-driven transcription. Finally, we demonstrated that the rapid phosphorylation and subsequent degradation of I kappa B-alpha induced by TPA was remarkably delayed by Bis knockdown. These results suggest that Bis regulates the invasive ability of glioma cells elicited by TPA, by modulating NF-kappa B activation, and subsequent induction of MMP-9 mRNA.