[Effects of dexamethasone on arsenic trioxide induced apoptosis, NF-kappaB activation and gene expression in lymphoma cell line]

To study the effect of dexamethasone (Dex) on the apoptosis and NF-kappaB activation in Raji cells as well as expression of MMP9 and VEGF induced by As2O3, and to observe the effect of inhibited activity of NF-kappaB by Dex on apoptosis.Cell apoptosis was analysed by Annexin V. Fluctuation of NF-kappaB, MMP9 and VEGF was detected by semi-quantitative immunohistochemistry.The apoptosis and activation of NF-kappaB of Raji cells could be induced by As2O3. The percentage of apoptosis was (39.2 +/- 1.3)%. Dex significantly increased (77.5%) the apoptosis induced by As2O3 (P0.05). Dex suppressed the activation of NF-kappaB induced by As2O3 (a suppression rate of 28.0%, P0.05). There was a positive correlation between the changes of MMP9, VEGF and NF-kappaB.As2O3 could induce apoptosis, activate NF-kappaB and up-regulate expression of MMP9 and VEGF of Raji cells. The mechanism of enhanced apoptosis by Dex may be related to suppressing activation of NF-kappaB and down-regulating expression of MMP9 and VEGF.