曲古抑菌素A下调人肺腺癌细胞A549内IDO表达的分子机制  

Molecular Mechanism of TSA-induced Down-regulation of IDO in Human Lung Adenocarcinoma Cell Line A549

作　　者：李玲玲[1] 江冠民[1] 杜军[1] 

机构地区：[1]中山大学药学院微生物与生化制药实验室,广东广州510006

出　　处：《中山大学学报（医学科学版）》2011年第6期752-757,共6页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：中国博士后科学基金(20100470976);国家自然科学基金(3087303281071712);国家"973"计划资助项目(2011CB935800)

摘　　要：【目的】研究曲古抑菌素A(TSA)抑制γ干扰素(IFN-γ)诱导的人A549细胞内吲哚胺2,3-双加氧酶(IDO)表达的分子机制。【方法】采用蛋白质免疫印迹技术检测TSA在IFN-γ诱导的A549细胞中IDO的表达、信号转导及转录激活子1(STAT1)的磷酸化和干扰素调节因子1(IRF-1)的激活等过程中的作用,在激光共聚焦显微镜下观察TSA对STAT1核转位的影响,利用双荧光素酶报告基因系统检测TSA对γ-干扰素激活位点(GAS)、干扰素刺激应答元件(ISRE)和核因子-κB(NF-κB)的激活的影响。【结果】TSA以浓度依赖方式下调A549细胞中IFN-γ诱导的IDO表达,并能明显抑制STAT1第701位酪氨酸的磷酸化和STAT1的核转位。双荧光素酶报告基因分析和Western blot结果表明:TSA能显著抑制GAS、ISRE和IRF-1的激活却不能抑制NF-κB的激活。【结论】TSA能下调IFN-γ诱导的A549细胞中IDO的表达,其机制可能是与其抑制STAT1的磷酸化和核转位,以及抑制STAT1与GAS的结合有关。[Objective] To investigate the molecular mechanism of TSA-induced indoleamine 2, 3-dioxygenase （IDO） down- regulation in human lung adenocarcinoma cell line A549. [Methods] The roles of TSA on the IFN-γ induced IDO expression in A549 cell, the phosphorylation of signal transducer and activator of transcription 1 （STAT1） and the activation of interferon regulatory factor 1 （IRF-1）were examined by western blotting. Effect of TSA on STAT1 nuclear translocation was observed by a confocal laser-scanning microscope. The lueiferase activity of the activation of y-interferon activated sites （GAS）, interferon stimulated response element （ISRE） and nuclear factor-KB （NF-KB） was measured by dual luciferase reporter assay system. [Results] TSA concentration- dependently reduced IFN-γ induced IDO expression, inhibited STAT1 phosphorylation at Tyr-701 and nuclear translocation in A549 cell. Dual luciferase reporter assay and Western blotting results showed that TSA blocked IFN-γinduced activation of GAS, ISRE, and IRF-1, but not NF-KB. [ Conclusions ] TSA can down-regulate IFN-γinduced IDO expression in A549 cell, which may be associated with the repression of phosphorylation and nuclear translocation of STAT1 and its binding to GAS.

关 键 词：TSA 人肺腺癌细胞A549 IDO STAT1 

分 类 号：R73-3[医药卫生—肿瘤]