Gao Chao, Zhao Wei, Liu Yi, Gong Wen-Yu, Li Wei-Jing, Li Zhi-Gang, Wu Min-Yuan
Center of Hematology, Beijing Children Hospital, Capital University of Medical Sciences, Beijing 100045, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2009 Oct;17(5):1283-8.
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.
本研究旨在探讨混合谱系白血病（MLL）重排阳性儿童急性淋巴细胞白血病（ALL）的融合基因转录本及免疫表型特征。采用多重巢式聚合酶链反应（PCR）检测601例ALL患者中MLL重排的发生率；通过PCR产物测序分析融合基因转录本的亚型及特征；比较22例MLL重排阳性ALL患者、30例从同期未检测到融合基因的患者中随机选取的阴性对照以及43例前B-ALL患者诊断时的免疫表型特征。结果显示，MLL阳性ALL的发生率为3.66%，占前B-ALL的29.9%。20例MLL重排阳性的B-ALL患者均为CD10阴性；携带CD13、CD33和CD34的患者数量低于无融合基因的前B-ALL患者，而CD20、CD22、CD2、CD5、CD7的表达无差异。检测到MLL-AF4、AF9、AF10和ENL 4种伙伴基因。MLL基因的融合位点主要位于外显子6、7、8，且1例患者中可能存在多种MLL融合位点；而其伙伴基因融合位点相对单一。1例MLL-AF10+患者的转录本中存在一个包含随机插入序列的转录本。结论是，尽管MLL重排发生率低，但有多种融合转录本，ALL患者在免疫表型和融合转录本方面具有独特的生物学特征。
