电离辐射反应中PML调控CXCR4的表达

目的：观察电离辐射反应中，肺癌细胞中受辐射感应分子早幼粒细胞白血病蛋白（PML）表达影响的信号分子，探讨PML是否参与调控辐射诱导的肿瘤转移过程。方法本实验采用特异性靶向PML的siRNA构建PML敲低表达细胞模型，钴-60辐照，而后用康成公司的基因表达谱芯片检测获得差异表达基因，经聚类分析挖掘与细胞间通讯、肿瘤转移有重要相关性的基因，进一步用反转录实时定量多聚酶链反应法（RT-qPCR）和蛋白质免疫印记法（WB）进行验证。结果应用基因表达谱芯片比较检测电离辐射反应中受PML影响的基因，筛选获得在非小细胞肺癌侵袭转移中发挥重要作用的C-X-C细胞因子受体4（CXCR4）在PML敲低表达的非小细胞肺癌A549细胞中表达显著上调；RT-qPCR和WB进一步在mRNA和蛋白水平验证PML敲低细胞中CXCR4的表达增高。结论在肺癌侵袭转移中发挥重要功能的CXCR4基因的表达受辐射感应分子PML的调控。

ObjectiveTo explore the role of PML in irradiation-induced tumor metastasis,and its down-stream targets involved in this process. MethodsPML-knock-down cells were obtained by transfection of specific siRNAs. Total RNAs were isolated from cells after irradiation,and gene expression profiles were analyzed by DNA microarray（NimbleGen Human Gene Expression Microarrays）. We evaluated the mRNA expression of PML and CXCR4 with reverse transcription real-time polymerase chain reaction（RT-qPCR）. Western-blot examination to examine PML and CXCR4 protein expression was also carried out.ResultsDNA microarray analysis showed that CXCR4 gene expression was increased in PML-knock-down cells. The microarray data of CXCR4 mRNA levels were further validated using RT-qPCR. Increased CXCR4 protein levels in PML-knock-down cells were successfully confirmed correspondingly.Conclusions Decreased CXCR4 expression may be one of the mechanisms in PML-mediated irradiation-induced tumor metastasis.