人质膜型唾液酸酶对丁酸钠诱导细胞凋亡的影响及其机制

目的：研究人质膜型唾液酸酶(hmSD)对丁酸钠(NaBT)诱导人雄激素非依赖型前列腺癌细胞(PC3细胞)凋亡的影响及其可能机制。方法：以前列腺癌细胞PC3和稳定转染hmSD的前列腺癌细胞(PC3-hmSD)为靶细胞，分别设对照组、NaBT 2.5 mmol?L^-1组、NaBT 5.0 mmol?L^-1组、NaBT 10.0 mmol?L^-1组，采用MTT法检测细胞存活率，吖啶橙/溴化乙啶(AO/EB)染色方法检测细胞凋亡情况，DCFH-DA激光共聚焦法检测细胞内ROS，Western blotting方法检测Bcl-XL、P65和Caspase 9蛋白表达。结果：① NaBT作用48和72 h时，PC3-hmSD细胞的生存率明显高于PC3细胞（P<0.05）；② NaBT 5.0 mmol?L^-1作用4 h，PC3-hmSD组细胞凋亡数明显少于PC3细胞（P<0.05）；③ NaBT诱导细胞内活性氧产生，PC3-hmSD细胞与PC3细胞比较差异无显著性；④ NaBT作用下，与PC3细胞比较，PC3-hmSD细胞Bcl-XL、P65蛋白表达水平增强，而 Caspase 9蛋白表达水平减低（P<0.05）。结论：① hmSD具有抵抗NaBT诱导细胞凋亡的作用；② hmSD对NaBT诱 导活性氧产生无抑制作用；③ hmSD抗凋亡作用可能与Bcl-XL和P65表达上调、Caspase 9表达下调有关。

Effect of hmSD on apoptosis induced by NaBT and its mechanism

Objective To study the effect of hmSD on apoptosis of PC3 cells induced by NaBT and its mechanism.Methods PC3 cells and PC3-hmSD stablely transfected with hmSD were used as target cells.Four groups were set up:control,NaBT 2.5 mmol·L-1,NaBT 5.0 mmol·L-1 and NaBT 10.0 mmol·L-1.The survival rate of cells was detected by MTT assay,apoptotic rate was determined with AO/EB assay,intracellular ROS was examined with DCFH-DA staining,the expressions of Bcl-XL,P65 and Caspase 9 were analyzed by Western blotting method.Results ①The survival rates of PC3-hmSD cells treated with NaBT for 48 and 72h were higher than that of PC3 cells(P<0.05). ② The apoptotic rate of PC3-hmSD cells treated with NaBT 5.0 mmol·L-1 for 4 h was lower than that of PC3 cells(P<0.05).③ There was no difference of ROS between both cell lines treated with NaBT.④ The result of Western blotting showed that the expression of Bcl-XL decreased in NaBT-treated PC3 cells,but it increased in PC3-hmSD cells.Compared with control group,the expressions of P65 and Caspase 9 increased in NaBT-treated cells,but the expression of P65 increased and the expression of Caspase 9 decreased in hmSD overexpressed cells(P<0.05).Conclusion ① NaBT can induce the apoptosis of PC3 cells,and hmSD can reverse it.② The pathway of hmSD against apoptosis may be no relation with the suppressed ROS synthesis.③ The antiapoptotic mechanism of hmSD may be involved in down-regulation of Caspase 9 and up-regulation of P65 and Bcl-XL expressions.