目的探讨针对bak的siRNA抑制由胶质瘤诱导的树突状细胞的凋亡及其可能机制。方法转染表达针对bak的siRNA序列的质粒(A:229序、B:310序、C:579序、D:NC序)进入树突状细胞,并利用C418筛选出稳定表达株,通过Western blot和逆转录.聚合酶链反应(RT-PCR)的方法鉴定出稳定表达有效干扰序列的树突状细胞;稳定表达有效干扰序列的树突状细胞和胶质瘤细胞共培养(b组),设置a组空白DC2.4、c组胶质瘤细胞和DC2.4共培养2个对照组,24h后采用噻唑蓝(MTT)比色法观察其活性,同时通过Western blot检测Casoase-3、Caspase-8、胞质中细胞色素c(Cytc)的含量。结果含有效siRNA的质粒转染入树突状细胞后,通过C418筛选出了稳定表达株。Western blot和RT—PCR检测出310序列bak的表达降低(Western blot:A:0.83、B:0.14、C:0.75、D:0.89、未转染:0.92;RT—PCR:A:0.42、B:0.08、C:0.39、D:0.46、未转染:0.49,P〈0.05)。稳定表达有效干扰序列的树突状细胞和胶质瘤细胞共培养后,与c组比较树突状细胞的活性较高,树突状细胞的Caspase-8表达量差异无统计学意义(a:0.78、b:0.75、C:0.77,P〉0.05),Caspase-3及胞质中的Cytc减少(Caspase-3:a:0.67、b:0.70、C:0.21;Cytc:a:0.70、b:0.71、C:0.17,P〈0.05)。结论胶质瘤可诱导树突状细胞凋亡,凋亡途径可能是线粒体途径;关于bak的siRNA可抑制胶质瘤细胞诱导的树突状细胞的凋亡。
Objective To study the inhibitory effects of siRNA targeting bak on the apoptosis of dendritic cells (DC) 2.4 that induced by glioma and to investigate the possible pathway of the apoptosis. Methods The vector expressing siRNA (A:229,B:310,C:579,D:NC) targeting bak was transfeeted into DC2.4 by the lipofectamine 2000 ,and the cells stably expressing the siRNA were selected by G418. The DC2.4 that stably expressing the siRNA were co-cultured with glioma (group B) Control group (group A) DC2.4 only, group c DC2.4 co-culture with glioma, and observe the activity of DC2.4. Investing the relategene ( Caspase-3, Caspase-8, Cytc) expression. Results When co-culture with glioma, the DC2.4 apoptosis. When the vector were transfected into DC2.4, the expression of bak were degraded ( Western blot : A : 0.83,B:0.14,C:0.75,D:0.89. un-transfected:0.92; RT-PCR:A:0.42, B:0.08,C:0.39, D:0.46. un- transfected :0.49, P 〈 0.05 ). When the DC2.4 that stably expressing siRNA target bak co-cuhure with glioma, the expression of Caspase-8 was not change ( a :0.78, b :0.75, c : 0.77, P 〉 0.05 ) , but the expression of Caspase-3 and the cytochrome C in endochylema was less than the unexpression siRNA one ( Caspase- 3:a:0.67,b:0.70,c:0.21;Cytc:a:0.70,b:0.71 ,c:0.17,P〈0.05). Conclusion The glioma can induce apoptosis of DC2.4. The pathway of apoptosis may be the mitoehondrial pathway;The siRNA targeting bak can degrade the apoptosis of DC2.4.