The t(8;21)(q22;q22) translocation, present in 10-15% of acute myeloid leukemia (AML) cases results in the production of the AML1/ETO fusion protein. Expression of AML1/ETO in patients or mouse models is not sufficient to induce AML. Despite convincing evidence that AML1/ETO is directly involved in the pathogenesis of AML, the underlying mechanism is not well understood. Genetic and biochemical...

One of the most frequent genetic aberrations in acute myeloid leukemia (AML) is chromosomal translocation between AML1/RUNX1 on chromosome 21 and ETO gene on chromosome 8 resulting in the expression of chimeric oncogene AML1-ETO. Although patients with t(8;21) translocation have good prognosis, 5-year survival is observed only in 50% of the cases. AML1-ETO translocation is usually accompanied b...

An inducible model for conditional expression of AML1-ETO in myeloid U-937 cells was generated previously to determine cellular effects of AML1-ETO and to identify target genes. Induction of AML1-ETO expression in U-937 resulted in reduced cell growth, G1 arrest and apoptosis. Microarray analysis showed more genes up-regulated than down-regulated (180 vs. 69). Clustering of AML1-ETO-positive an...

AML1-ETO is the translational product of a chimeric gene created by the stable chromosome translocation t (8;21)(q22;q22). It causes acute myeloid leukemia (AML) by dysregulating the expression of genes critical for myeloid cell development and differentiation and recently has been reported to bind multiple subunits of the mammalian cytosolic chaperonin TRiC (or CCT), primarily through its DNA ...

Targeting of gene regulatory factors to specific intranuclear sites may be critical for the accurate control of gene expression. The acute myelogenous leukemia 8;21 (AML1/ETO) fusion protein is encoded by a rearranged gene created by the ETO chromosomal translocation. This protein lacks the nuclear matrix-targeting signal that directs the AML1 protein to appropriate gene regulatory sites within...

The transcription factor PU.1 plays a pivotal role in normal myeloid differentiation. PU.1(-/-) mice exhibit a complete block in myeloid differentiation. Heterozygous PU.1 mutations were reported in some patients with acute myeloid leukemia (AML), but not in AML with translocation t(8;21), which gives rise to the fusion gene AML1-ETO. Here we report a negative functional impact of AML1-ETO on t...

In previous studies, we showed that induction of pulmonary artery (PA) smooth muscle cell (SMC) elastase activity by serum-treated elastin (STE) requires DNA transcription. We therefore used differential mRNA display to identify transcripts expressed coincident with elastase induction. Twenty-four individual transcripts were differentially expressed from a screen of approximately 2000 mRNA sequ...

The 8;21 translocation is a major contributor to acute myeloid leukemia (AML) of the M2 classification occurring in approximately 40% of these cases. Multiple mouse models using this fusion protein demonstrate that AML1-ETO requires secondary mutagenic events to promote leukemogenesis. Here, we show that the negative cell cycle regulator p21(WAF1) gene is up-regulated by AML1-ETO at the protein...

not conclusive, it suggests an alternative model of TEL-AML1 leukemogenesis (see figure, Model B). In this model, the initiating event (TEL-AML1 fusion) is as rare as the disease itself, implying that a high proportion (perhaps 100%) of babies born with a detectable TEL-AML1 fusion are destined to develop TEL-AML1 ALL. Could newborn screening for TEL-AML1 be considered in this scenario? Assumin...

The AML1 gene, situated in 21q22, is often rearranged in acute leukemias through t(8;21) translocation, t(12;21) translocation, or less often t(3;21) translocation. Recently, point mutations in the Runt domain of the AML1 gene have also been reported in leukemia patients. Observations for mutations of the Runt domain of the AML1 gene in bone marrow cells were made in 300 patients, including 131...