目的 研究急性早幼粒细胞白血病（APL）中BAX基因的表达水平及其被调控的机制。方法 使用real-time PCR方法对APL患者中BAX基因表达水平进行分析；使用染色质免疫共沉淀技术对PML/RARα融合基因在BAX基因上的结合情况进行分析；使用Western blotting及real-time PCR方法对药物诱导PML/RARα降解后BAX基因和蛋白的表达情况进行分析。结果 BAX在APL样本中显著低表达；PML/RARα直接结合在BAX基因的启动子区域；诱导PML/RARα降解后，BAX基因的表达显著上调。结论 在急性早幼粒细胞中，PML/RARα直接结合在BAX基因启动子区域，抑制其启动子活性使得BAX基因的表达在急性早幼粒细胞被抑制。

Objective To investigate the expression level of BAX gene of acute promyelocytic leukemia (APL) and its regulation mechanism. Methods The expression level of BAX gene of patients with APL was detected by the real-time PCR. The enrichment of PML/RARα fusion protein at the promoter region of BAX gene was detected by the chromatin immunoprecipitation (ChIP). The expression level of BAX gene and protein after the drug induced degradation of PML/RARα was detected by the real-time PCR and Western blotting. Results The expression level of BAX gene in APL samples was significantly low. PML/RARα fusion protein directly bound the promoter region of BAX gene. The expression level of BAX gene significantly increased after PML/RARα was induced to degrade. Conclusion PML/RARα inhibits the expression of BAX gene in APL by directly binding to the promoter region of BAX gene and inhibiting the activity of promoter.