Apoptotic effect of 4,5,6,7-tetrabromobenzotriazole on human cervical cancer HeLa cells and its mechanism / 吉林大学学报(医学版)

Objective:To investigate the promotive effect of 4,5,6,7-tetrabromobenzotriazole (TBB) on the apoptosis of the human cervical cancer HeLa cells,and to clarify its effect mechanism in related signaling pathways.Methods:The human cervical cancer HeLa cells at logarithmic growth phase were divided into control group(without TBB) and experiment group(with TBB).MTT assay was used to detect the survival rate of the HeLa cells;the morphology of HeLa cells was observed under inverted microscope;Annexin Ⅴ-FITC/PI double staining and flow cytometry(FCM) were used to determine the apoptotic rates of the HeLa cells;the expression levels of apoptosis-related proteins p-Akt,Akt,Bcl-2,Bax,cleaved-caspase-3,and Pro-caspase-3 were detected by Western blotting method.Results:The MTT results showed that the survival rates of the HeLa cells in experiment group were significantly decreased(P<0.01) in a dose-dependent manner compared with control group.The apoptotic morphology of the HeLa cells in experiment group were found as cell shrinkage and karyopyknosis under inverted microscope.The Annexin Ⅴ-FITC/PI double staining and FCM results showed that the apoptotic rates of the HeLa cells in experiment group (3,6,12 and 24 h) were higher than that in control group (P<0.05 or P<0.01).The Western blotting results showed that compared with control group,the expression levels of the anti-apoptotic proteins p-Akt and Bcl-2 in HeLa cells in experiment group were decreased obviously,whereas the expression levels of the pro-apoptotic proteins Bax and cleaved-caspase-3 were increased and the expression levels of Pro-caspase-3 were decreased.Conclusion:TBB may promote the apoptosis of human cervical cancer HeLa cells by inhibiting the Akt signaling pathway.

Role of Casein Kinase 2 in Parkinsonian Toxin 1-Methyl-4-phenylpyridinium-induced Cell Death

BACKGROUND: Protein casein kinase 2 is involved in signal transduction, cell growth, and apoptosis. However, it has not been elucidated whether parkinsonian toxin 1-methyl-4-phenylpyridinium (MPP+)-induced neuronal cell death is mediated by a casein-kinase-2-mediated pathway. METHODS: We monitored apoptosis-related protein activation, changes in the level of casein kinase 2, nuclear damage, and apoptosis in differentiated PC12 cells exposed to MPP+ in combination with casein kinase 2 inhibitor. RESULTS: Casein kinase 2 inhibitors [4,5,6,7-tetrabromobenzotriazole (TBB), 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, and apigenin] reduced MPP+- and rotenone-induced cell death in differentiated PC12 cells. TBB inhibited the MPP+-induced activation of apoptosis-related proteins (decreases in Bid and Bcl-2 levels, increase in Bax levels, cytochrome c release, and caspase-3 activation), increase in casein kinase 2 levels, and nuclear damage. CONCLUSIONS: Administering casein kinase 2 inhibitor TBB at concentrations that do not induce toxic effects may reduce MPP+-induced cell death in differentiated PC12 cells by suppressing the apoptosis-related protein activation that leads to cytochrome c release and subsequent activation of caspase-3. The results suggest that MPP+-induced cell death process is mediated by a casein kinase 2 pathway.