论文部分内容阅读
目的:研究异常转录因子早幼粒白血病-维甲酸受体α(promyelocytic leukemia-retinoic acid receptor alpha,PML-RARα)融合蛋白对RIAM基因的转录调控机制。方法:利用表达谱数据库(GSE1159)比较RIAM基因在急性髓系白血病(acute myeloid leukemia,AML)各亚型中的表达情况,以及RIAM基因和PML-RARα融合蛋白之间的相关性。采用蛋白质印迹法和实时荧光定量-PCR法分别检测PML-RARα融合蛋白和RIAM基因在急性早幼粒细胞白血病(acute promyelocytic leukemia,APL)模式细胞株PR9及APL患者来源的细胞株NB4中的表达情况,以及在全反式维甲酸(all-trans retinoicacid,ATRA)处理前后的RIAMmRNA的表达情况。利用染色质免疫沉淀技术检测细胞内PML-RARα融合蛋白在RIAM基因启动子附近的结合情况。结果:RIAM基因在APL(即M3型AML)中的表达水平明显低于其他AML亚型(M0、M1、M2、M4、M5和M7型)和正常造血细胞(P<0.05)。随着PML-RARα融合蛋白的表达,RIAM基因的表达水平明显降低。ATRA能激活RIAM基因的表达,且PML-RARα融合蛋白的表达能增强ATRA对RIAM基因表达的激活效应。PML-RARα融合蛋白结合在RIAM基因的启动子区域。结论:RIAM基因是PML-RARα融合蛋白的靶基因,PML-RARα融合蛋白通过结合到RIAM基因的启动子区域对其转录进行负调控。
OBJECTIVE: To study the transcriptional regulation of RIAM gene by the promiscuous transcription factor promyelocytic leukemia-retinoic acid receptor alpha (PML-RARα) fusion protein. METHODS: The expression of RIAM gene in various subtypes of acute myeloid leukemia (AML) and the relationship between RIAM gene and PML-RARα fusion protein were compared by using the expression profile database (GSE1159). Western blotting and real-time fluorescence quantitative PCR were used to detect the expression of PML-RARα fusion protein and RIAM gene in cell line PR4 of patients with acute promyelocytic leukemia (APL) model and NB4 cell line of APL As well as the expression of RIAM mRNA before and after treatment with all-trans retinoic acid (ATRA). Chromatin immunoprecipitation was used to detect the intracellular binding of PML-RARα fusion protein near the RIAM gene promoter. Results: The expression level of RIAM gene in APL (M3 type AML) was significantly lower than that of other AML subtypes (M0, M1, M2, M4, M5 and M7) and normal hematopoietic cells (P <0.05). With the expression of PML-RARα fusion protein, the expression level of RIAM gene was significantly reduced. ATRA can activate the expression of RIAM gene, and the expression of PML-RARα fusion protein can enhance the activation effect of ATRA on RIAM gene expression. The PML-RARα fusion protein binds to the promoter region of the RIAM gene. Conclusion: The RIAM gene is the target gene of PML-RARα fusion protein, and the PML-RARα fusion protein negatively regulates its transcription by binding to the promoter region of RIAM gene.