MLL基因重排阳性的儿童急性淋巴细胞白血病的融合基因及免疫表型特点  

Characteristics of Fusion Gene and Immunophenotype in MLL Gene Rearrangement Positive Childhood Acute Lymphoblastic Leukemia

作　　者：高超[1] 赵玮[1] 刘怡[1] 巩文玉[1] 李伟京[1] 李志刚[1] 吴敏媛[1] 

机构地区：[1]首都医科大学附属北京儿童医院血液病中心,北京100045

出　　处：《中国实验血液学杂志》2009年第5期1283-1288,共6页Journal of Experimental Hematology

基　　金：北京市科技计划资助项目,编号D0905001040431;北京市科技新星计划资助项目,编号2005B06

摘　　要：为了探讨混合谱系白血病(mixed linage leukemia,MLL)基因重排阳性的儿童急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)融合基因与免疫表型的特征,利用多重巢式聚合酶链反应(polymerase chain reaction,PCR)方法检测601例ALL患儿中MLL基因重排的发生率,通过对PCR产物的测序,分析融合基因的亚型及特点;比较分析重排阳性的22例患儿与同期未检出任何融合基因的随机抽取的30例ALL患儿及43例pro-B-ALL患儿初诊时免疫表型特点。结果表明:MLL基因重排阳性的ALL患儿检出率为3.66%,占pro-B-ALL的29.9%。20例MLL基因重排阳性的B-ALL患者全部为CD10-,表达CD13、CD33和CD34的例数较pro-B-ALL对照组低,CD20、CD22、CD2、CD5、CD7的表达则无差异。共检出4种MLL基因的伙伴基因AF4、AF9、AF10和ENL。MLL基因融合位点主要位于第6、7、8外显子,同一患者可同时存在多种MLL基因融合位点;而其伙伴基因的融合位点相对单一。1例患儿MLL-AF10融合转录本存在随机插入序列。结论:MLL基因重排的发生率低,重排形式多样,阳性ALL患儿在免疫表型及融合转录本的表达方面具有独特的生物学特征。The study was aimed to investigate the fusion gene transcript and immunophenotypic characteristics of the mixed linage leukemia （MLL）-rearranged positive childhood acute lymphoblastic leukemia （ALL）. The incidence of MLL rearrangement in 601 cases of ALL patients was detected by the multiple-nested polymerase chain reaction （PCR）; the subtypes and features of the fusion gene transcript were analyzed by PCR products sequencing; the immunophenotypic characteristics at diagnosis were compared between the 22 MLL rearrangement positive of ALL patient, 30 negative control which selected randomly from the patients whose fusion gene could not be detected in the same term and 43 pro-B-ALL patients. The results showed that the incidence of MLL positive ALL was 3.66%, constituted 29.9% of the pro-B-ALL. The MLL rearrangement positive 20 B-ALL patients were all CD10 negative; the number of patients who carried CD13, CD33 and CD34 was lower than that of pro-B-ALL who had no fusion gene, whereas the expression of CD20, CD22, CD2, CD5, CD7 showed no difference. 4 kind partner genes of MLL-AF4, AF9, AF10 and ENL were detected. The fusion loci of MLL gene were mainly located at the exon 6, 7, 8 and many kind of fusion loci of MLL may exist in one patient; whereas its partner gene fusion loci were relatively single. A transcript contains a random insert sequence existed in a transcript of one MLL- AF10 ^＋ patient. It is concluded that though incidence of MLL rearrangement is low, but it has a variety of fusion transcripts, the ALL patients has unique biological characteristics at immunophenotype and fusion transcript.

关 键 词：急性淋巴细胞白血病 混合谱系白血病 基因重排 免疫袁型 

分 类 号：R733.71[医药卫生—肿瘤]