抑制胆囊癌细胞内Janus激酶/信号转导与转录激活子1信号通路以下调吲哚胺2,3双加氧酶表达的意义

摘要

Objective To investigate the mechanism on JAK/STAT1 signal pathway in SAHA down-regulation of indoleamine 2,3-dioxygenase (IDO) in gallbladder carcinoma cells.Methods We treated gallbladder carcinoma SGC-996 cells with IFN-γ and SAHA.Western blotting was used to detect the expression of IDO,signal transducer and activator of transcription 1 (STAT1) phosphorylation and interferon regulatory factor genes-1 (IRF-1).Confocal microscopy analysis was used to detect STAT1 translocation.Transient transfections and reporter genes assay was used in detecting the activation of γ-activated sites (GAS) and interferon stimulated response elements (ISRE).Results IDO expressed in SGC-996 cells in dose- and time-dependent manners when stimulated with IFN-γ.SAHA down-regulated the expression of IDO induced by IFN-γ in a dose-dependent manner.SAHA blocked the expression of IRF-1 induced by IFN-γ.SAHA inhibited the IFN-γ-induced STAT1 phosphorylation and nuclear translocation.SAHA down-regulated IFN-γ-induced activation of GAS and ISRE.Conclusions SAHA may down-regulate IDO expression through inhibiting the activation of members in JAK/STAT1 signal pathway.This may provide a new immunotherapeutic strategy to break tumor immune tolerance in gallbladder carcinoma.%目的 探讨调控胆囊癌细胞内Janus激酶(JAK)/信号转导与转录激活子1(STAT1)信号通路抑制吲哚胺2,3双加氧酶(IDO)表达的作用机制,为解除胆囊癌生物治疗中肿瘤产生的免疫耐受提供理论依据.方法 应用γ-干扰素和组蛋白去乙酰化酶抑制剂SAHA处理胆囊癌SGC996细胞.Western blot方法检测IDO、STAT1以及干扰素调节转录因子1(IRF-1)的表达.用细胞免疫组化和激光共聚焦显微镜观察STAT1的入核情况,转染和荧光素酶报告基因分析γ激活序列(GAS)和干扰素刺激反应元件(ISRE)的活性.结果 胆囊癌细胞中IFN-γ刺激IDO的表达呈剂量和时间依赖性.SAHA抑制IDO的表达呈剂量依赖性.SAHA抑制STAT1的磷酸化和入核,抑制IFN-γ促进的GAS、ISRE和IRF-1的活性.结论 抑制人胆囊癌细胞中JAK/STAT1信号通路可导致IDO表达下降,表明调控JAK/STAT1信号通路可能会解除胆囊癌生物治疗中肿瘤产生的免疫耐受.