Kawano S, Miyanishi S, Shimizu K, Tanaka K, Okumura A, Ohki M, Kamada N, Ohno Y
Department of Haematology, Tenri Hospital, Nara, Japan.
Br J Haematol. 1997 Dec;99(3):632-40. doi: 10.1046/j.1365-2141.1997.4593264.x.
We have investigated a case of acute myelocytic leukaemia derived from myelodysplastic syndrome (MDS-AML) with an 8;21 translocation. In this case the AML1/MTG8 (ETO) fusion transcript was not detected by reverse transcriptase-polymerase chain reaction (RT-PCR), and the rearrangement of the AML1 gene locus was not detected by Southern blot nor pulse field gel electrophoresis (PFGE) analyses using specific probes for the AML1 gene. Fluorescence in-situ hybridization (FISH) study using cosmid probes for 21q22 revealed that the breakpoint of 21q22 was telomeric to the AML1 gene locus and centromeric from D21S259, 351, 3421 loci. This is the first report concerning the t(8;21)(q22;q22) carrying AMLs (de novo AML, MDS-AML and therapy-related AML) to show that the breakpoint at 21q22 is located outside the AML1 gene locus. It is also noteworthy that the cell-surface antigen expression pattern of the bone marrow (BM) blasts was changed from CD7+ CD2+ CD13+ CD33+ CD19- CD11b+ CD14+ CD36+ to CD7- CD2- CD13+ CD19+ CD11b- CD14- CD33+ CD34+ CD36- CD56+ during leukaemic progression, and the pattern in leukaemic phase was similar to the characteristic phenotype of de novo AML cases with t(8;21), when the AML1/MTG8 fusion transcripts are always detected by RT-PCR.
我们研究了一例源自骨髓增生异常综合征（MDS-AML）且伴有8;21易位的急性髓细胞白血病病例。在该病例中，通过逆转录聚合酶链反应（RT-PCR）未检测到AML1/MTG8（ETO）融合转录本，并且使用针对AML1基因的特异性探针，通过Southern印迹法和脉冲场凝胶电泳（PFGE）分析均未检测到AML1基因位点的重排。使用针对21q22的黏粒探针进行的荧光原位杂交（FISH）研究表明，21q22的断点位于AML1基因位点的端粒侧，且位于D21S259、351、3421位点的着丝粒侧。这是关于携带t(8;21)(q22;q22) 的急性髓细胞白血病（初发急性髓细胞白血病、MDS-AML和治疗相关急性髓细胞白血病）的首篇报道，显示21q22处的断点位于AML1基因位点之外。同样值得注意的是，在白血病进展过程中，骨髓原始细胞的细胞表面抗原表达模式从CD7+ CD2+ CD13+ CD33+ CD19- CD11b+ CD14+ CD36+ 转变为CD7- CD2- CD13+ CD19+ CD11b- CD14- CD33+ CD34+ CD36- CD56+，白血病期的模式类似于初发t(8;21)急性髓细胞白血病病例的特征性表型，此时通过RT-PCR总能检测到AML1/MTG8融合转录本。
