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 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.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Acute Disease
-
CCAAT-Enhancer-Binding Protein-alpha / biosynthesis
-
CCAAT-Enhancer-Binding Protein-alpha / genetics
-
CD11b Antigen / biosynthesis
-
CD11b Antigen / genetics
-
Cell Differentiation
-
Cell Size / drug effects
-
Cholecalciferol / pharmacology
-
Chromosomes, Human, Pair 21 / genetics
-
Chromosomes, Human, Pair 8 / genetics
-
Core Binding Factor Alpha 2 Subunit
-
Drug Design
-
Gene Expression Regulation, Leukemic / drug effects
-
Humans
-
Leukemia, Myeloid / genetics*
-
Leukemia, Myeloid / metabolism
-
Leukemia, Myeloid / pathology
-
Neoplasm Proteins / biosynthesis
-
Neoplasm Proteins / genetics
-
Oncogene Proteins, Fusion / antagonists & inhibitors*
-
Oncogene Proteins, Fusion / genetics
-
RNA Interference*
-
RNA, Messenger / antagonists & inhibitors
-
RNA, Messenger / genetics
-
RNA, Messenger / metabolism
-
RNA, Small Interfering / physiology*
-
RUNX1 Translocation Partner 1 Protein
-
Receptor, Macrophage Colony-Stimulating Factor / biosynthesis
-
Receptor, Macrophage Colony-Stimulating Factor / genetics
-
Transcription Factors / antagonists & inhibitors*
-
Transcription Factors / genetics
-
Transfection
-
Transforming Growth Factor beta / pharmacology
-
Transforming Growth Factor beta1
-
Translocation, Genetic
-
Tumor Cells, Cultured / metabolism
-
Tumor Cells, Cultured / ultrastructure
-
Tumor Stem Cell Assay
Substances
-
AML1-ETO fusion protein, human
-
CCAAT-Enhancer-Binding Protein-alpha
-
CD11b Antigen
-
Core Binding Factor Alpha 2 Subunit
-
Neoplasm Proteins
-
Oncogene Proteins, Fusion
-
RNA, Messenger
-
RNA, Small Interfering
-
RUNX1 Translocation Partner 1 Protein
-
TGFB1 protein, human
-
Transcription Factors
-
Transforming Growth Factor beta
-
Transforming Growth Factor beta1
-
Cholecalciferol
-
Receptor, Macrophage Colony-Stimulating Factor