1. AML1/MTG8 oncogene suppression by small interfering RNAs supports myeloid differentiation of t(8;21)-positive leukemic cells
- Author
-
Matthias John, Gerhard Heil, Olaf Heidenreich, Philipp Hadwiger, Juergen Krauter, Alfred Nordheim, Heidemarie Riehle, and Hans-Peter Vornlocher
- Subjects
Small interfering RNA ,Oncogene Proteins, Fusion ,Chromosomes, Human, Pair 21 ,Cellular differentiation ,Immunology ,Transitive RNA interference ,Receptor, Macrophage Colony-Stimulating Factor ,Transfection ,Biochemistry ,Translocation, Genetic ,Transforming Growth Factor beta1 ,RUNX1 Translocation Partner 1 Protein ,Transforming Growth Factor beta ,hemic and lymphatic diseases ,Enhancer binding ,CCAAT-Enhancer-Binding Protein-alpha ,Tumor Cells, Cultured ,Humans ,RNA, Messenger ,RNA, Small Interfering ,neoplasms ,Tumor Stem Cell Assay ,Cell Size ,Cholecalciferol ,CD11b Antigen ,Ccaat-enhancer-binding proteins ,Oncogene ,biology ,Gene Expression Regulation, Leukemic ,Myeloid leukemia ,Cell Differentiation ,Cell Biology ,Hematology ,Transforming growth factor beta ,Molecular biology ,Neoplasm Proteins ,Leukemia, Myeloid ,Drug Design ,Acute Disease ,Core Binding Factor Alpha 2 Subunit ,Cancer research ,biology.protein ,RNA Interference ,Chromosomes, Human, Pair 8 ,Transcription Factors - Abstract
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 β1 (TGFβ1)/vitamin D3–induced differentiation, leading to increased expression of CD11b, macrophage colony-stimulating factor (M-CSF) receptor, and C/EBPα (CAAT/enhancer binding protein). Moreover, siRNA-mediated AML1/MTG8 suppression results in changes in cell shape and, in combination with TGFβ1/vitamin D3, 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.
- Published
- 2003