[Effects of Transcription Factor MZF-1 on Transcriptive Regulation of Acute Monocytic Leukemia-related Gene MLAA-34].

To investigate the transcriptional regulation of transcription factor MZF-1 on acute monocytic leukemia-related gene MLAA-34. The effect of MZF-1 on the transcriptional activity of MLAA-34 gene promoter was analyzed by luciferase reporter gene detection system and site-directed mutation technique. The EMSA and ChIP assay were used to verify whether MZF-1 directly and specifically binds to the core region of MLAA-34 promoter. The over-expression vector and interference vector of MZF-1 were constructed to transfect U937 cells, and RT-PCR and Western blot were used to detect the transcription and expression changes of MLAA-34 gene. The transcription factor MZF-1 had a regulatory effect on MLAA-34 gene expression, and the relative luciferase activity was decreased after MZF-1 binding point mutation (P<0.01). EMSA and ChIP experiments demonstrated that MZF-1 could directly bind to MLAA-34 promoter and play a regulatory role. In the over-expression test, the increase of MZF-1 could up-regulate the expression of MLAA-34 (P<0.05). In the interference test, the decrease of MZF-1 could down-regulate the expression of MLAA-34 (P<0.05). Transcription factor MZF-1 can bind to the transcriptional regulatory region on the promoter of MLAA-34 gene and promote the transcription of MLAA-34 gene in acute monocytic leukemia. 转录因子MZF-1对急性单核细胞白血病新抗原基因MLAA-34的转录调控研究. 探讨转录因子MZF-1对急性单核细胞白血病新抗原基因MLAA-34的转录调控作用. 利用双萤光素酶报告基因检测系统及定点突变技术分析MZF-1 对MLAA-34基因启动子转录活性的影响。通过凝胶电泳迁移率变动检测（electrophoretic mobility slift assay,EMSA）和染色质免疫沉淀检测（chromatin immunoprecipitation,ChIP）实验，验证MZF-1是否与MLAA-34启动子核心区直接特异性结合。构建MZF-1真核表达载体和干涉载体，转染U937细胞，应用RT-PCR 和Western blot法检测MLAA-34基因的转录和表达变化. 转录因子MZF-1对MLAA-34基因表达具有调控作用，MZF-1结合序列点突变后，相对荧光素酶活性降低（P<0.01）。EMSA和ChIP实验从细胞内、外水平分别证明MZF-1可与MLAA-34启动子直接结合而发挥调控作用。在过表达试验中，MZF-1的增加可上调MLAA-34的表达（P<0.05）；在干涉试验中，MZF-1的降低可下调MLAA-34的表达（P<0.05）. 转录因子MZF-1可与MLAA-34基因启动子上的转录调控区结合，并促进急性单核细胞白血病细胞中MLAA-34基因的转录.