Heidenreich Olaf, Krauter Jürgen, Riehle Heidemarie, Hadwiger Philipp, John Matthias, Heil Gerhard, Vornlocher Hans-Peter, Nordheim Alfred
Department of Molecular Biology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany.
Blood. 2003 Apr 15;101(8):3157-63. doi: 10.1182/blood-2002-05-1589. Epub 2002 Dec 12.
The translocation t(8;21) yields the leukemic fusion gene AML1/MTG8 and is associated with 10%-15% of all de novo cases of acute myeloid leukemia. We demonstrate the efficient and specific suppression of AML1/MTG8 by small interfering RNAs (siRNAs) in the human leukemic cell lines Kasumi-1 and SKNO-1. siRNAs targeted against the fusion site of the AML1/MTG8 mRNA reduce the levels of AML1/MTG8 without affecting the amount of wild-type AML1. These data argue against a transitive RNA interference mechanism potentially induced by siRNAs in such leukemic cells. Depletion of AML1/MTG8 correlates with an increased susceptibility of both Kasumi-1 and SKNO-1 cells to tumor growth factor beta(1) (TGF beta(1))/vitamin D(3)-induced differentiation, leading to increased expression of CD11b, macrophage colony-stimulating factor (M-CSF) receptor, and C/EBP alpha (CAAT/enhancer binding protein). Moreover, siRNA-mediated AML1/MTG8 suppression results in changes in cell shape and, in combination with TGF beta(1)/vitamin D(3), severely reduces clonogenicity of Kasumi-1 cells. These results suggest an important role for AML1/MTG8 in preventing differentiation, thereby propagating leukemic blast cells. Therefore, siRNAs are promising tools for a functional analysis of AML1/MTG8 and may be used in a molecularly defined therapeutic approach for t(8;21)-positive leukemia.
8号与21号染色体易位产生白血病融合基因AML1/MTG8，与10% - 15%的急性髓系白血病初发病例相关。我们证明了小干扰RNA（siRNA）在人白血病细胞系Kasumi - 1和SKNO - 1中对AML1/MTG8具有高效且特异性的抑制作用。靶向AML1/MTG8 mRNA融合位点的siRNA可降低AML1/MTG8水平，而不影响野生型AML1的量。这些数据反驳了siRNA在此类白血病细胞中可能诱导的传递性RNA干扰机制。AML1/MTG8的缺失与Kasumi - 1和SKNO - 1细胞对肿瘤生长因子β(1)（TGFβ(1)）/维生素D(3)诱导分化的敏感性增加相关，导致CD11b、巨噬细胞集落刺激因子（M - CSF）受体和C/EBPα（CAAT/增强子结合蛋白）表达增加。此外，siRNA介导的AML1/MTG8抑制导致细胞形态改变，并且与TGFβ(1)/维生素D(3)联合使用时，严重降低Kasumi - 1细胞的克隆形成能力。这些结果表明AML1/MTG8在阻止分化从而增殖白血病原始细胞中起重要作用。因此，siRNA是对AML1/MTG8进行功能分析的有前景的工具，并且可用于t(8;21)阳性白血病的分子靶向治疗方法。
