DACT1基因羟甲基化在儿童WT1、IDH1/2、TET2基因突变的急性髓细胞白血病中的特征及临床意义  

Characteristics and clinical significance of DACT1 hydroxymethylation in childhood acute myeloid leukemia with mutant WT1,IDH1/2,or TET2

作　　者：闭军琴 包黎明[1] 王兴娟[1] 豆虎[2] 杨珍珍 于洁[3] 陈希[1] Bi Junqin;Boo Liming;Wang Xingjuan;Dou Hu;Yang Zhenzhen;Yu Jie;Chen Xi(Center for Clinical Molecular Medicine;Department of Clinical Laboratory;Department of Hematology,The Children's Hospital of Chongqing Medical University)

机构地区：[1]重庆医科大学附属儿童医院临床分子医学中心,重庆400014 [2]重庆医科大学附属儿童医院临检中心,重庆400014 [3]重庆医科大学附属儿童医院血液科,重庆400014

出　　处：《重庆医科大学学报》2019年第2期139-145,共7页Journal of Chongqing Medical University

基　　金：国家自然科学基金资助项目(编号:81802092);重庆市科委基础科学与前沿技术研究资助项目(编号:cstc2016jcyjA1053);重庆市卫计委医学科研计划资助项目(编号:2017MSXM040)

摘　　要：目的:研究dapper,β-连环蛋白拮抗剂,非洲爪蟾同系物1(dapper,antagonist of beta-catenin,homolog 1 Xenopus laevis,DACT1)在儿童急性髓细胞白血病(acute myeloid leukemia,AML)中的羟甲基化特征及其与预后的关系,寻找AML新的危险分层分子标志物。方法:测序分析本院血液科初发AML188例,根据是否存在Wilms肿瘤因子1(Wilms tumor 1,WT1)、异柠檬酸脱氢酶1/2(isocitrate dehydrogenase 1/2,IDH1/2)或TET蛋白2(ten-eleven translocation,TET2)基因突变,将病例分为WIT-AML组(30例)和非WIT-AML组(158例);用糖基化qPCR及qPCR方法检测WIT-AML(16例)、非WIT-AML(14例)和非AML患儿(14例)的DACT1基因羟甲基化水平(5-hydroxymethylcytosine,5hmC)和表达水平,并用Spearman法研究羟甲基化与表达的相关性;随访患儿的缓解、复发及生存情况,采用COX回归分析DACT1羟甲基化对AML患儿总生存率(overall survival,OS)及无病生存率(event free survival,EFS)的影响。结果:WIT-AML组的DACT1 a、b区域(DACT1 a/b)甲基岛(CpG)羟甲基化(5hmC)水平较非WIT-AML组低(Ua=48.00,Pa=0.008;Ub=19.00,Pb=0.000),且其基因表达明显减低(Uexp=0.00,Pexp=0.000);DACT1 a/b甲基岛5hmC与DACT1的表达水平呈正相关(ra=0.812,Pa=0.000;rb=0.789,Pb=0.000);DACT1a 5hmC水平减低是EFS的危险因素(HR=3.896,95%CI=1.161~13.073,P=0.028),同样也是OS的危险因素(HR=4.109,95%CI=1.226~13.771,P=0.022)。结论:在WITAML中,DACT1 5hmC水平和表达水平明显降低,DACT1a区5hmC水平降低可增加儿童AML生存风险,可作为AML一个新的独立预后不良指标。Objective:To study the characteristics of hydroxymethylation of dapper,antagonist of beta-catenin,homolog 1(Xenopus laevis)(DACT1)in childhood acute myeloid leukemia(AML)and its relationship with prognosis,and to identify the new molecular marker for the risk classification of AML. Methods:This study included 188 newly diagnosed AML cases in Department of Hematology,The Children’s Hospital of Chongqing Medical University. Sanger sequencing was employed to analyze the mutation in Wilms’ tumor1(WT1),isocitrate dehydrogenase 1/2(IDH1/2),or ten-eleven translocation(TET2). These cases were assigned to either WIT-AML group(n=30) or non-WIT-AML group(n=158) according to the presence or absence of mutation in any of the above genes. The hydroxymethylation(5-hydroxymethylcytosine,5 hmC)level of the DACT1 gene and the expression of DACT1 were assessed using glycosylation qPCR and qPCR for 16 WIT-AML cases,14 non-WIT-AML cases,and 14 non-AML cases. The correlation between the hydroxymethylation and expression of DACT1 was investigated by Spearman analysis. Data on the remission,relapse,and survival of children were acquired by follow-up. Cox regression analysis was employed to assess the effect of DACT1 hydroxy-methylation on the overall survival(OS)and event-free survival(EFS)rates of children with AML. Results:Compared with the non-WIT-AML group,the WIT-AML group had a significantly lower 5 hmC level at the CpG island of DACT1 a/b(Ua=48.00,Pa=0.008;Ub=19.00,Pb=0.000),as well as significantly reduced DACT1 expression(Uexp=0.00,Pexp=0.000). Moreover,DACT1 a/b 5 hmC level was positively correlated with DACT1 expression(ra=0.812,Pa=0.000;rb =0.789,Pb=0.000). Reduced DACT1 a 5 hmC was associated with shorter survival(EFS:hazard ratio [HR]=3.896,95% confidence interval[CI]=1.161-13.073,P=0.028;OS:HR=4.109,95%CI=1.226-13.771,P=0.022). Conclusion:In WITAML,DACT1 5 hmC level and DACT1 expression are significantly decreased. Reduced DACT1 a 5 hmC is associated with shorter survival in children with AML,so it can be used as an i

关 键 词：儿童 急性髓细胞白血病 dapper β-连环蛋白拮抗剂 非洲爪蟾同系物1 羟甲基化 预后 

分 类 号：R733.7[医药卫生—肿瘤]