神经酰胺对人膀胱癌细胞凋亡诱导作用及其机制

Apoptosis inducing effect and its mechanism of ceramide to human bladder cancer cells

目的探讨神经酰胺(cer)对人膀胱癌细胞的凋亡诱导作用及其机制。方法不同浓度C_2-神经酰胺(C_2-cer)作用于膀胱癌T24细胞,噻唑蓝(MTT)比色法检测细胞存活率,吖啶橙(AO)荧光染色、流式细胞术(FCM)检测细胞凋亡,并对半胱天冬酶(Caspase)-3活性、bcl-2蛋白含量和细胞色素C在细胞内的分布变化进行检测。结果T24细胞存活率与C_2-cer浓度呈负相关(r=-0．973,P＜0．01)。对照组和5、10、20、40μmol/L的C_2-cer处理组凋亡率分别为2．95％、9．18％、14．23％、29．12％、48．46％,C_2-cer处理组凋亡率显著高于对照组(P＜0．01)。Caspase-3活性随C_2-cer浓度增加而增加,与对照组比较差异有统计学意义(P＜0．05)。在C_2-cer作用下,T24细胞内bcl-2蛋白含量下降,细胞色素C向细胞质释放。结论降低bcl-2蛋白表达水平,从而促进线粒体细胞色素C释放和Caspase-3激活可能是C_2-cer诱导膀胱癌细胞凋亡的重要机制。

Objective To study the apoptosis inducing effect and its mechanism of ceramide to human bladder cancer cells. Methods Different concentrations of C2-ceramide （C2-cer） were applied to human bladder cancer T24 cells,then MTT method was used to assay survival rates, fluorescent staining with acridine orange （AO） and flow cytometer （FCM） were used to detect cell apoptosis. Changes of Caspase-3 activity, bcl-2 protein and the intracellular distribution of cytochrome C were also detected. Resuits The survival rate of T24 cells showed a negative correlation to the concentrations of C2-cer （ r = - 0. 973, P〈0.01 ）. The apoptotic rate in control group and the groups of 5,10,20,40 μmol/L of C2- cer was 2.95 %, 9.18 %, 14.23 %, 29.12 % and 48.46 %, respectively. The apoptotic rate in different concentrations of C2-cer was higher than that of the control group （P〈0.01 ）. The activities of Caspase-3 were increased with the concentrations of C2-cer （P〈0.05 or P〈0.01 ）. During the apoptosis of T24 cells induced by C2-cer, the amount of bcl-2 protein was decreased and cytochrome C was released from mitochondria. Conclusion C2-cer may induce apoptosis of human bladder cancer T24 cells by decreasing the amount of bcl-2 protein, promoting the release of cytochrome C and the activation of Caspase-3.