Taviaux S, Brunel V, Dupont M, Fernandez F, Ferraz C, Carbuccia N, Sainty D, Demaille J, Birg F, Lafage-Pochitaloff M
CNRS-IGH, Montpellier, France.
Genes Chromosomes Cancer. 1999 Feb;24(2):165-71. doi: 10.1002/(sici)1098-2264(199902)24:2<165::aid-gcc12>3.0.co;2-1.
We report on the molecular characterization of two acute myeloid leukemias (AML), one AML-M1 (patient 1) and one AML-M2 (patient 2) with t(8;21)(p21;q22) and t(8;20)(q22;p13), respectively, at diagnosis. The locations of the breakpoints, 21q22 in patient 1 and 8q22 in patient 2, prompted us to search for a cryptic t(8;21)(q22;q22) and involvement of the AML1 and ETO genes. Dual-color fluorescence in situ hybridization (FISH) using whole chromosome painting probes for chromosomes 8, 20, and 21 confirmed the conventional cytogenetic karyotypes. However, dual-color FISH using appropriate ETO and AML1 probes disclosed an insertion of AML1 into 8q22 on the derivative chromosome 8 in patient 1 and of ETO into 21q22 on one chromosome 21 in patient 2, leading to AML1-ETO fusion signals. Both cases expressed an AML1-ETO transcript, shown by reverse transcriptase polymerase chain reaction and cDNA sequencing. Creation of functional AML1-ETO fusion genes in these two simple variant t(8;21) probably occurred through complex mechanisms, combining translocation and insertion of chromosomal segments.
我们报告了两例急性髓系白血病（AML）的分子特征，其中一例为AML-M1（患者1），另一例为AML-M2（患者2），诊断时分别具有t(8;21)(p21;q22)和t(8;20)(q22;p13)。患者1的断点位于21q22，患者2的断点位于8q22，这促使我们寻找隐匿的t(8;21)(q22;q22)以及AML1和ETO基因的受累情况。使用针对8号、20号和21号染色体的全染色体涂染探针进行双色荧光原位杂交（FISH），证实了传统细胞遗传学核型。然而，使用合适的ETO和AML1探针进行双色FISH显示，患者1的衍生8号染色体上AML1插入到8q22，患者2的一条21号染色体上ETO插入到21q22，导致AML1-ETO融合信号。两例均通过逆转录聚合酶链反应和cDNA测序显示表达AML1-ETO转录本。这两种简单变异型t(8;21)中功能性AML1-ETO融合基因的产生可能是通过复杂机制，将染色体片段的易位和插入结合在一起。
