人端粒酶逆转录酶基因启动子区CpG岛甲基化在儿童白血病中的意义  

Significance of methylation of CpG island in promoter domain of human telomerase reverse transcriptase gene in leukemia in children

作　　者：李康[1] 祁新坤[1] 张鹏辉[2] 邹琳[1] 

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 儿童发育相关疾病研究教育部重点实验室 儿科学重庆市重点实验室 重庆市儿童发育重大疾病诊治与预防国际科技合作基地,重庆400014 [2]重庆医科大学附属儿童医院临检中心,重庆400014

出　　处：《中国生物制品学杂志》2013年第7期997-1001,共5页Chinese Journal of Biologicals

基　　金：国家自然科学基金(90919013;30871103);重庆市自然科学基金(2010BA5008);教育部"新世纪优秀人才支持计划"基金项目(2008-CET)

摘　　要：目的探讨人端粒酶逆转录酶(human telomerase reverse transcriptase,hTERT)基因启动子区CpG岛甲基化及甲基化位点与儿童白血病临床特征的相关性。方法收集儿童白血病患者173例(Leu组),根据白血病亚型不同分为:急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)94例、急性髓细胞白血病(acute myelocytic leukemia,AML)52例、慢性粒细胞白血病(chronic granulocytic leukemia,CML)19例及复发难治的白血病(acute leukemia,AL)8例(ALL 5例,AML 3例),以非恶性血液病(NL组)42例作为对照。分离患者外周血单核细胞,提取基因组DNA,经甲基化修饰试剂盒修饰后,采用甲基化特异性-PCR(methylation specific-PCR,MS-PCR)法分别检测Leu组、NL组患者外周血标本单个核细胞中hTERT基因启动子区两个CpG岛不同位点甲基化情况,并分析其与儿童白血病临床特征的相关性。结果 hTERT基因启动子区CpG岛在NL组呈完全非甲基化,在复发难治的白血病组呈甲基化状态。NL组外周血中hTERT基因启动子区2号CpG岛(-2016～-1532和-1415～-1151)呈完全非甲基化状态,而Leu组呈甲基化状态,且甲基化更易发生在1号和2号(-2016～-1532)位点,但hTERT基因启动子区1号CpG岛甲基化在NL组和Leu组中差异无统计学意义(P>0.05)。hTERT基因启动子区甲基化与患者年龄、外周血白细胞数、免疫分型、细胞遗传标志及危险分级相关(P<0.05),与患者性别、融合基因无关(P>0.05)。结论儿童白血病患者hTERT基因启动子区CpG岛易发生甲基化,与甲基化位点分布相关,对儿童白血病的诊断具有重要意义。Objective To investigate the relationship of methylation of CpG island in promoter domain of human telomerase reverse transcriptase（hTERT） gene and methylation site to clinical characters of leukemia in children.Methods One hundred and seventy-three children with leukemia（Leu group） enrolled in this study were divided into 4 groups according to leukemia subtypes,i.e.acute lymphoblastic leukemia（ALL） group（94 cases）,acute myeloblastic leukemia（AML） group（52 cases）,chronic myelocytic leukemia（CML） group（19 cases） and relapse acute leukemia（AL） group（8 cases,including 5 cases of ALL and 3 cases of AML）,using 42 sex-and age-matched patients without malignant hematological diseases as control（NL group）.The peripheral blood mononuclear cells（PBMCs） of patients were isolated,from which genomic DNAs were extracted,and modified by methylation modification kit,while those in Leu and NL groups were determined for methylation of various sites of two CpG islands in promoter domain of hTERT gene by methylation specific-PCR（MS-PCR）.The relationship between the methylation and clinical characters of leukemia in children was analyzed.Results The CpG islands in promoter domain of hTERT gene were completely unmethylated in NL group,while were methylated in AL groups.The CpG island 2（site-2 016 ^-1 532 and site-1 415 ~ 1 151 was completely unmethylated in NL group,while was methylated in Leu group.The methylation was more frequently in site-2 016 ^-1 532.However,the methylation level of CpG island 1 showed no significant difference in NL and Leu groups（P 0.05）.The methylation was related to the age,leukocyte count in peripheral blood,immunophenotype and cellular genetic marker（P 0.05）,while was unrelated to the sex or fusion gene of patients（P 0.05）.Conclusion The CpG island in promoter domain of hTERT gene in children with leukemia was easily to be methylated,which was unrelated to the distribution of methylation sites.It is of an important significance in diagnosis

关 键 词：人端粒酶逆转录酶基因 启动子 CPG岛 甲基化 白血病 儿童 

分 类 号：R733.7[医药卫生—肿瘤]