Izraeli S, Henn T, Strobl H, Ludwig W D, Kovar H, Haas O A, Harbott J, Bartram C R, Gadner H, Lion T
Children's Cancer Research Institute, St Anna Children's Hospital, Vienna, Austria.
Leukemia. 1993 Dec;7(12):2054-6.
The translocation t(1;19)(q23;p13) in pediatric patients with acute lymphoblastic leukemia (ALL) was demonstrated in early reports to result in a consistent fusion between the E2A and PBX1 gene sequences and in the expression of a uniform, chimeric E2A/PBX1 mRNA with transforming potential. More recent observations suggested that cytogenetically identical t(1;19) translocations can result in the transcription of different mRNA species and that expression of the E2A/PBX1 message may be restricted to patients with the t(1;19) who display a pre-B phenotype of ALL. To further assess the correlation between the immunologic subtypes of the disease and specific genetic alterations, we have performed cytogenetic and molecular analyses in 221 children with B-lineage ALL. Expression of the chimeric E2A/PBX1 message was detected in 21 patients. Out of 14 patients, in whom cytoplasmic immunoglobulin (cig) analyses were available, no less than four had a cig- B-cell precursor ALL, whereas 10 displayed a cig+ B-ALL immunophenotype. These findings are at variance with a recent report in which expression of the E2A/PBX1 message was linked exclusively to a subset of patients who displayed a cig+ pre-B-cell precursor phenotype of ALL. In seven cases diagnosed before 1986, cig analyses were not available, and consequently E2A/PBX1 expression could not be correlated to a particular immunological subtype of B-cell precursor ALL. Our results have important implications for the detection of residual disease in pediatric patients where expression of the typical E2A/PBX1 mRNA may occur both in cig+ (pre-B) and cig- (early pre-B) immunologic subtypes of ALL.
早期报告显示，小儿急性淋巴细胞白血病（ALL）患者中的t(1;19)(q23;p13)易位会导致E2A和PBX1基因序列持续融合，并产生具有转化潜能的一致的嵌合E2A/PBX1 mRNA。最近的观察结果表明，细胞遗传学上相同的t(1;19)易位可导致不同mRNA种类的转录，并且E2A/PBX1信息的表达可能仅限于表现出ALL前B表型的t(1;19)患者。为了进一步评估该疾病的免疫亚型与特定基因改变之间的相关性，我们对221例B系ALL儿童进行了细胞遗传学和分子分析。在21例患者中检测到嵌合E2A/PBX1信息的表达。在14例可进行细胞质免疫球蛋白（cig）分析的患者中，不少于4例患有cig - B细胞前体ALL，而10例表现出cig + B - ALL免疫表型。这些发现与最近的一份报告不同，在该报告中，E2A/PBX1信息的表达仅与表现出ALL的cig +前B细胞前体表型的患者亚组相关。在1986年之前诊断的7例病例中，无法进行cig分析，因此E2A/PBX1表达无法与B细胞前体ALL的特定免疫亚型相关联。我们的结果对于检测小儿患者的残留疾病具有重要意义，其中典型E2A/PBX1 mRNA的表达可能在ALL的cig +（前B）和cig -（早期前B）免疫亚型中均出现。
