Project description:U937 AML cells that express an inducible AML1-ETO construct under the control of the tetracycline promoter. Microarrays used to discover an AML1-ETO signature for a GE-HTS screen to identify AML1-ETO modulators.
Project description:U937 AML cells that express an inducible AML1-ETO construct under the control of the tetracycline promoter. Microarrays used to discover an AML1-ETO signature for a GE-HTS screen to identify AML1-ETO modulators. Experiment Overall Design: U937 AML cells that express an inducible AML1-ETO construct under the control of the tetracycline promoter at 0, 12, 24, 48, and 72 hours and corresponding controls (2 replicates each).
Project description:This SuperSeries is composed of the following subset Series:; GSE15646: Kasumi-1 AML1-ETO knockdown samples; GSE15647: U937 AML1-ETO inducible samples Experiment Overall Design: Refer to individual Series
Project description:This SuperSeries is composed of the following subset Series: GSE10520: Genes regulated by AML1/ETO in U937 cells GSE10537: Gene expression profiling of AML1/ETO regulated genes and binding pattern on human promoters in U937 cells GSE10578: AML1/ETO, AML1, and HEB binding patterns on chromosme 19 GSE10579: Analysis of expression levels of genes on chromosome 19 in U937 cells expressing AML1/ETO Keywords: SuperSeries Refer to individual Series
Project description:Approximately 20% of Acute Myelogenous Leukemia (AML) cases carry the t(8;21) translocation, which involves the AML1 and ETO genes, and express the resulting AML1/ETO fusion protein that functions as a transcriptional repressor by recruiting NCoR/SMRT/HDAC complexes to DNA. We used microarrays to identify genes differentially expressed in U937 cells expressing AML1/ETO compared to vector transfected U937 cells. Keywords: Transcriptional regulation
Project description:Approximately 20% of Acute Myelogenous Leukemia (AML) cases carry the t(8;21) translocation, which involves the AML1 and ETO genes, and express the resulting AML1/ETO fusion protein that functions as a transcriptional repressor by recruiting NCoR/SMRT/HDAC complexes to DNA. We used microarrays to identify human promoters bound by AML1/ETO in U937 cells. Keywords: ChIP-chip
Project description:The ETO-family transcriptional corepressors, including ETO, ETO2 and MTGR1, are all involved in leukemia-causing chromosomal translocations. In every case, an ETO-family corepressor acquires a DNA-binding domain (DBD) to form a typical transcription factor – the DBD binds to target genes, while the ETO moiety contributes essentially to its transcriptional property. A direct comparative study of these “homologous” fusion transcription factors may clarify their similarities and differences in regulating transcription and leukemogenesis. Here, we performed a side-by-side comparison between AML1-ETO and ETO2-GLIS2, the most common fusion proteins in the M2 and M7 subtypes of acute myeloid leukemia, respectively, by inducible expression of them in U937 leukemia cells. We found that, although AML1-ETO and ETO2-GLIS2 can use their own DBDs (i.e., the Runt domain of AML1 and the zinc finger domain of GLIS2) to bind DNA, they actually share a large proportion of genome-wide binding regions dependent on other cooperative transcription factors such as ETS- and CEBP-family proteins. Functionally, AML1-ETO acts as either transcriptional repressor or activator, whereas ETO2-GLIS2 mainly acts as an activator. The repressor-versus-activator functions of AML1-ETO is determined by the abundance of cooperative transcription factors/cofactors on the target genes. Through these mechanisms, AML1-ETO and ETO2-GLIS2 differentially regulate several key transcription factors that are essential for myeloid differentiation. Indeed, AML1-ETO inhibits myeloid differentiation of U937 cells, whereas ETO2-GLIS2 facilitates it. Taken together, this study is the first direct comparative study between AML1-ETO and ETO2-GLIS2 in the same cellular context, and the results provide new insights into the context-dependent transcriptional regulatory mechanisms that may underlie how these seemingly “homologous” fusion transcription factors exert distinct functions to drive different subtypes of leukemia.
Project description:Approximately 20% of Acute Myelogenous Leukemia (AML) cases carry the t(8;21) translocation, which involves the AML1 and ETO genes, and express the resulting AML1/ETO fusion protein that functions as a transcriptional repressor by recruiting NCoR/SMRT/HDAC complexes to DNA. We used microarrays to identify genes differentially expressed in U937 cells expressing AML1/ETO compared to vector transfected U937 cells. Experiment Overall Design: A U937 cell line that conditionally expresses HA-tagged AML1/ETO under the control of the mouse metallothionine promoter (U937-A1E) (Alcalay et al., J.Clin.Invest, 2003,112, 1751-1761) was used. A cell line caryying the empty vector was used as control Cells were treated for 8h with 100uM ZnSO4 to induce transgene expression. For each of the U937 cell lines (AML1/ETO and Mt), three independent RNA extractions were performed, and an equal quantity of each of the three RNA preparations was then mixed to generate an RNA pool for each sample.
Project description:Approximately 20% of Acute Myelogenous Leukemia (AML) cases carry the t(8;21) translocation, which involves the AML1 and ETO genes, and express the resulting AML1/ETO fusion protein that functions as a transcriptional repressor by recruiting NCoR/SMRT/HDAC complexes to DNA. We used ChIP-chip to identify the determinants of AML1/ETO binding on a contiguous DNA region (chromosome 19). AML1/ETO binding regions are characterized by a specific sequence signature that includes the presence of the consensus binding sites for the AML1 and HEB transcription factors. We therefore assessed the binding patterns of AML1 and HEB on chromosome 19. A specific chromatin modification (tri-methylation of lysine 4 on histone 3 = 3MetK4) was also studied in U937 cells expressing AML1/ETO in order to correlate the identified binding profiles with active transcription sites. Keywords: ChIP-chip A U937 cell line that conditionally expresses HA-tagged AML1/ETO under the control of the mouse metallothionine promoter (U937-A1E) (Alcalay et al., J.Clin.Invest, 2003,112, 1751-1761) was used. Cell lines were treated for 8h with 100uM ZnSO4 to induce transgene expression in U937-A1E. We performed ChIP using anti-HA, anti-ETO, anti-AML1/RUNX1, anti-HEBor anti-3MetK4 antibodies. ChIP products were then PCR amplified, labeled with Cy3/Cy5 fluorescent dyes and hybridized to the NimbleGen custom made NGS_HG17_Chr.19Array. U937-Mt cells, which carry the empty vector, served as control (C) for non-specific antibody binding. Each sample identifier indicates Antibody_Cell line (example: HA_A1E = ChIP using anti HA antibody in U937-A1E cells; HA_C = ChIP using anti HA antibody in U937-Mt control cells)