Arsenic trioxide induced leukemic cell apoptosis relative to NF-kappaB activation / 中国实验血液学杂志

To investigate the relationship of As(2)O(3)-induced leukemic cell apoptosis with NF-kappaB activation and expression of VEGF, MMP9, apoptosis of K562-n cells induced by As(2)O(3) was analyzed by Annexin V, the dynamic changes of NF-kappaB, MMP9 and VEGF expressions were detected by immunohistochemistry. The results showed that activity of NF-kappaB could be increased, accompanied by higher level of expression of MMP9 and VEGF when apoptosis of K562-n cells was induced by As(2)O(3). Dexamethasome not only increased significantly the apoptotic rate, but also suppressed the activation of NF-kappaB of K562-n cells induced by As(2)O(3). Furthermore, there was a positive correlation between the expression of MMP9, VEGF and the activity of NF-kappaB. It is concluded that As(2)O(3) can induce apoptosis, in the meanwhile, activate NF-kappaB and up-regulate expression of MMP9 and VEGF in K562-n cell line. The mechanism of apoptosis of K562-n cells enhanced by dexamethasome may be related to suppression of the activation of NF-kappaB and expression of MMP9 and VEGF.

Effects of dexamethasone on arsenic trioxide induced apoptosis, NF-kappaB activation and gene expression in lymphoma cell line / 中华血液学杂志

<p><b>OBJECTIVES</b>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.</p><p><b>METHODS</b>Cell apoptosis was analysed by Annexin V. Fluctuation of NF-kappaB, MMP9 and VEGF was detected by semi-quantitative immunohistochemistry.</p><p><b>RESULTS</b>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 (P < 0.05). Dex suppressed the activation of NF-kappaB induced by As2O3 (a suppression rate of 28.0%, P < 0.05). There was a positive correlation between the changes of MMP9, VEGF and NF-kappaB.</p><p><b>CONCLUSIONS</b>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.</p>