Marín C, Martínez-Delgado B, Meléndez B, Larrayoz M J, Martínez-Ramírez A, Robledo M, Cigudosa J C, Calasanz M J, Benítez J
Dept. of Human Genetics, Centro Nacional de Investigaciones Oncológicas, Ctra. Majadahonda-Pozuelo Km 2, Majadahonda 28220 Madrid, Spain.
Haematologica. 2001 Dec;86(12):1254-60.
The presence of specific chromosomal translocations in acute lymphoblastic leukemias (ALL) plays an important role in determining the prognosis of the patients. Our aim is to develop a highly sensitive and specific method to screen simultaneously for the four most frequent translocations in ALL: t(9;22), t(1;19), t(4;11), t(12;21).
Our approach uses a multiplex-polymerase chain reaction (PCR) method, which involves two rounds of PCR using fluorescence-labeled nested primers. The chimeric transcripts resulting from these translocations can be identified by agarose gel electrophoresis or by fluorescence analysis. To validate this method we carried out the analysis in 42 pediatric ALL samples previously studied by cytogenetic and fluorescent in situ hybridization (FISH) techniques.
In all samples with a known translocation detected by cytogenetic or FISH techniques, the same translocation was identified by the multiplex-PCR assay. Moreover, with this method we detected rearrangements in five patients in clinical remission and in two patients at diagnosis for whom karyotypes were normal and rearrangements had not been detected. The application of this multiplex-PCR assay was also useful in cases without cytogenetic results.
These results show that the multiplex-PCR method allows reliable, sensitive and rapid detection of the prognostically significant translocations in ALL. We believe that this assay combined with cytogenetic analysis should be the strategy of choice for the initial diagnostic phase of acute lymphoblastic leukemia, and that it could be used not only at diagnosis but also to follow-up these alterations in remission samples without previous controls.
急性淋巴细胞白血病（ALL）中特定染色体易位的存在对确定患者预后起着重要作用。我们的目标是开发一种高度灵敏且特异的方法，用于同时筛查ALL中四种最常见的易位：t(9;22)、t(1;19)、t(4;11)、t(12;21)。
我们的方法采用多重聚合酶链反应（PCR），该方法涉及两轮使用荧光标记巢式引物的PCR。这些易位产生的嵌合转录本可通过琼脂糖凝胶电泳或荧光分析来鉴定。为验证该方法，我们对42例先前通过细胞遗传学和荧光原位杂交（FISH）技术研究过的儿童ALL样本进行了分析。
在所有通过细胞遗传学或FISH技术检测到已知易位的样本中，多重PCR检测也鉴定出了相同的易位。此外，通过该方法我们在5例临床缓解期患者和2例诊断时核型正常且未检测到重排的患者中检测到了重排。这种多重PCR检测在没有细胞遗传学结果的病例中也很有用。
这些结果表明，多重PCR方法能够可靠、灵敏且快速地检测ALL中具有预后意义的易位。我们认为，该检测方法与细胞遗传学分析相结合应是急性淋巴细胞白血病初始诊断阶段的首选策略，并且它不仅可用于诊断，还可用于对缓解期样本中这些改变的随访，而无需先前的对照。
