Dickkopf1(DKK-1)基因甲基化在急性白血病中的表达分析

Analysis of methylation of the Dickkopf1(DKK-1) gene in acute leukemia

目的探讨WNT/β-catenin通路的关键抑制因子Dickkopf1(DKK-1)基因异常甲基化与急性白血病(AL)发病机制的相关性。方法采用逆转录聚合酶链式反应(RT-PCR)方法检测4个AL细胞系(NB4、Jurkat、Molt-4、CEM)、65例AL患者及20例正常对照骨髓单个核细胞中DKK-1基因mRNA的表达情况;采用甲基化特异性PCR(M SP)方法检测各标本及细胞系中DKK-1基因启动子区域的甲基化状态。结果与正常对照组比较,AL患者DKK-1基因mRNA表达量显著降低(P<0.05);正常对照组标本单个核细胞中不存在DKK-1基因的甲基化;DKK-1在AL患者中甲基化率为37.7%(24/65),其中急性淋巴细胞白血病(ALL)患者中甲基化率为41.2%(14/34),急性髄系白血病(AML)患者中甲基化率为28.6%(10/31)。结论 DKK-1甲基化及异常表达在急性白血病中是一种较为普遍的现象,其参与了部分急性白血病的发病过程。

Objective To investigate the relationship between the abnormal methylation of the Dickkopf1（DKK-1） gene,which is a key inhibiting factor of the WNT/β-catenin pathway,and acute leukemia（AL）.Methods Reverse Transcription Polymerase Chain Reaction（RT-PCR） was used to examine DKK-1 mRNA expression in 4 AL cell lines（NB4,Jurkat,Molt-4,and CEM） of 65 AL patients and 20 normal controls.Methylation-Specific Polymerase Chain Reaction（MSP） was used to examine the CpG-island methylation status of the DKK-1 gene in AL cell lines of AL patients and the controls.Results Compared with that in the normal controls,the expression of the DKK-1 gene was significantly reduced in the AL patients（P〈0.05）.None of the normal mononuclear cells showed methylation of the DKK-1 gene.DKK-1 methylation was found in 24 of the 65（37.7%） AL patients.The frequencies of aberrant DKK-1 methylation were 41.2%（14/34） in the acute lymphoblastic leukemia（ALL） patients,and 28.6%（10/31） in the acute myelocytic leukemia（AML） patients.Conclusions Methylation and aberrant expression of the DKK-1 gene are common in AL and also play a role in the pathogenesis of some AL.