RNAi抑制STAT3表达、活化诱导人胶质瘤干细胞凋亡与分化

Inhibition of STAT3 expression and activation by RNAi induces apoptosis and differentiation of human glioblastoma stem cells in vitro

目的抑制人胶质瘤干细胞(GSCs)信号转导活化转录因子3(STAT3)表达、活化,了解STAT3在细胞凋亡、分化调节中的作用。方法 RNAi抑制人GSCs中STAT3表达、活化,流式细胞分析检测细胞凋亡和干细胞比例变化;实时定量多聚酶链反应(PCR)和Weastern-blot检测Bcl-2、BAX、Caspase-3表达;干扰组和对照组GSCs接种裸鼠,观察成瘤情况。结果干扰组人GSCs凋亡比例(16.03%)显著高于空白组(2.03%)和阴性对照组(3.19%)(P<0.05),CD133+细胞比例(5.7%)显著低于空白组(92.2%)和阴性对照组(87.7%);干扰组Bcl-2表达显著低于空白组和阴性对照组(P<0.05);裸鼠移植瘤实验中,阴性对照组3只成瘤,而干扰组均未成瘤。结论抑制人GSCs中STAT3表达、活化,可诱导凋亡,促进分化,抑制其成瘤能力。细胞凋亡增加可能与Bcl-2表达下调有关。

Objective To observe the effect of signal transduction and activation of transcription 3（STAT3） on apoptosis and differentiation in human glioblastoma stem cells after inhibition of STAT3 expression and activation.Methods STAT3 was silenced with RNAi in human glioblastoma stem cells（hGSCs）.The rates of CD133＋ cells and apoptotic cells were analyzed by flow cytometry after inhibition of STAT3 expression and activation in hGSCs.The expressions of Bcl-2,BAX and Caspase-3 genes were analyzed by real-time Q-PCR and Western blot.The capacity of forming tumor in hGSCs with STAT3 silencing was observed after in vivo implantation into nude mice.Results The rate of apoptotic cells in hGSCs with STAT3 silencing（16.03%） was significantly increased compared with control groups（2.03% and 3.19%）（P0.05）.The expression of Bcl-2 in hGSCs with STAT3 silencing was significantly lower than that of control groups（P0.05）.The rate of CD133＋ cells in hGSCs with STAT3 silencing（5.7%） was significantly decreased compared with control groups（92.2% and 87.7%）（P0.05）.Transplanted glioblastomas formed in 3 nude mice with control hGSCs implantation and no tumor formed in 5 mice with hGSCs implantation after STAT3 silencing.ConclusionInhibition of STAT3 expression and activation induces the apoptosis and differentiation of hGSCs.The capacity of forming tumor is inhibited in hGSCs with STAT3 silencing.The apoptosis of hGSCs with STAT3 silencing might be related to the down-regulation of Bcl-2 expression.