Apoptosis inducing effect of cell exogenous ceramide on human bladder cancer cells and mechanism

Objective To study the apoptosis inducing effect of cell exogenous ceramide on human bladder cancer cells and the mechanism.Methods Human bladder cancer T24 cells were treated with 10,20,40 μmol/L of C2-ceramide (C2-cer),and observed by inverted microscope.The morphological changes of apoptotic cells were examined by fluorescent staining with acridine orange (AO).Flow cytometry (FCM) was used to detect apoptosis rate,and Western blotting was done to detect the change of intracellular distribution of apoptosis inducing factor (AIF).Results Under the action of C2-cer,significant morphological changes of apoptosis appeared in T24 cells.The apoptosis rate in control group and C2-cer-treated (10,20,40 μmol/L) groups was 2.95％,14.23％,29.12％ and 48.46％,respectively.The apoptosis rate in C2-cer-treated groups was significantly higher than in control group (P ＜ 0.01).AIF in control group was located only in mitochondrion.The AIF amount in mitochondria of C2-cer-treated groups was significantly less than in control group (t =25.3,P ＜0.01).At the saMe time,AIF could be detected in the nucleus of C2-cer-treated groups.Conclusion Cell exogenous ceramide may induce dose-dependent apoptosis of human bladder cancer cells.The transferring of AIF from mitochondria to cell nucleus may play a critical role during this process. Key words: Ceramide ;  Bladder neoplasms ;  Apoptosis inducing factor