Project description:Acute myeloid leukemia (AML), and other myeloid malignancies, are frequently treated with hypomethylating agents like decitabine. Alterations in the epigenome, induced by decitabine, are likely to result in gene expression changes. The effects of decitabine have not been systemically studied using primary AML samples. We cultured 18 different primary AML samples for 7 days, the last 3 days of which included 100 nM decitabine (DAC) or 100 nm cytarabine (AraC). We hypothesized that decitabine treatment would result in detectable and consistent gene expression changes. For comparison, we also analyzed mRNA from cells treated with DMSO control (mock) and mRNA from uncultured cells taken at the time of diagnosis.
Project description:Genome-wide DNA methylation profiling of primary AML samples treated with 100nM decitabine (DAC), cytarabine (AraC), or DMSO. Eight distinct AML samples were grown using an in vitro stromal co-culture system for 4 days and then treated with either DAC, Ara-C or DMSO for 3 days. DNA was prepared for genome-wide methylation analysis with the Illumina Infinium 450k Human DNA methylation BeadChip. DNA from each sample/treatment was analyzed on duplicate arrays.
Project description:Genome-wide DNA methylation profiling of primary AML samples treated with 100nM decitabine (DAC), cytarabine (AraC), or DMSO. Eight distinct AML samples were grown using an in vitro stromal co-culture system for 4 days and then treated with either DAC, Ara-C or DMSO for 3 days. DNA was prepared for genome-wide methylation analysis with the Illumina Infinium 450k Human DNA methylation BeadChip. DNA from each sample/treatment was analyzed on duplicate arrays. Bisulfite-converted DNA from 24 samples was hybridised to the Illumina Infinium 450k Human Methylation Beadchip in duplicate (replicates are indicated by array plate number).
Project description:The DNA hypomethylating drug decitabine maintains normal hematopoietic stem and progenitor cell (HSPC) self-renewal but induces terminal differentiation in acute myeloid leukemia (AML) cells. To better understand the basis for this contrasting treatment effect, the baseline expression of key lineage-specifying transcription factor (TF) (eg., CEBPa) and key late differentiation TF (CEBPe), was examined in normal, myelodysplastic (MDS) and AML primary cells and cell lines. To appreciate the role of differentiation in hypomethylation of some CpG by decitabine treatment but not others, promoter CpGs, analyzed by microarray and mass spectrometry, were categorized by the direction of methylation change during normal myeloid differentiation. In MDS/AML cells, high expression of CEBPa, relatively low expression of CEBPe (a gene target of CEBPa), hypermethylation of CEBPe promoter CpG, and the methylation pattern at differentiation sensitive promoter CpGs analyzed by microarray, suggested lineage-commitment and aberrant epigenetic repression of late differentiation genes. DNA hypomethylation in response to decitabine was greatest at CpGs that are hypomethylated during normal myeloid differentiation. In contrast, normal HSPC treated with decitabine retained immature morphology, and methylation significantly decreased at CpG that are hypermethylated during myeloid differentiation. Partial differentiation at baseline, and repression of key late differentiation genes by epigenetic means, likely plays a role in methylation and phenotype responses of AML cells treated with decitabine. Bisulphite converted DNA from the 208 samples were hybridised to the Illumina Cancel Panel 1 GPL9183 methylation assay
Project description:The DNA hypomethylating drug decitabine maintains normal hematopoietic stem and progenitor cell (HSPC) self-renewal but induces terminal differentiation in acute myeloid leukemia (AML) cells. To better understand the basis for this contrasting treatment effect, the baseline expression of key lineage-specifying transcription factor (TF) (eg., CEBPa) and key late differentiation TF (CEBPe), was examined in normal, myelodysplastic (MDS) and AML primary cells and cell lines. To appreciate the role of differentiation in hypomethylation of some CpG by decitabine treatment but not others, promoter CpGs, analyzed by microarray and mass spectrometry, were categorized by the direction of methylation change during normal myeloid differentiation. In MDS/AML cells, high expression of CEBPa, relatively low expression of CEBPe (a gene target of CEBPa), hypermethylation of CEBPe promoter CpG, and the methylation pattern at differentiation sensitive promoter CpGs analyzed by microarray, suggested lineage-commitment and aberrant epigenetic repression of late differentiation genes. DNA hypomethylation in response to decitabine was greatest at CpGs that are hypomethylated during normal myeloid differentiation. In contrast, normal HSPC treated with decitabine retained immature morphology, and methylation significantly decreased at CpG that are hypermethylated during myeloid differentiation. Partial differentiation at baseline, and repression of key late differentiation genes by epigenetic means, likely plays a role in methylation and phenotype responses of AML cells treated with decitabine.
Project description:Acute myeloid leukemia (AML), and other myeloid malignancies, are frequently treated with hypomethylating agents like decitabine. Alterations in the epigenome, induced by decitabine, are likely to result in gene expression changes. The effects of decitabine have not been systemically studied using primary AML samples.
Project description:Genome wide DNA methylation profiling of AML patient samples treated with PBS or DAC. The Illumina Infinium 450 Human DNA methylation was used to examine the methylation profile of 8 patient samples and 2 cell lines. Genome wide DNA methylation profiling of AML xenografts treated with either PBS control or with decitacine (DAC) alone, cytarabine (Ara-C) alone, DAC and Ara-C together (D+A), DAC followed by Ara-C (D/A) or with Ara-C followed by DAC (A/D).
Project description:The Affymetrix Human Genome U133 Plus 2.0 Array was used to examine the Genome wide transcriptional changes which follow the treatment of AML xenografts with either PBS control or combination of decitabine (DAC) and cytarabine (Ara-C). Animals were treated with PBS, DAC alone, Ara-C alone, DAC and Ara-C combined (D+A), DAC followed by Ara-C (D/A) or Ara-C followed by DAC (A/D). PBS vs each drug combination
Project description:We found previously that the effect of decitabine (DAC) on hematopoietic stem cell viability differed between Mll5 wildtype and null cells. We therefore investigated the role of MLL5 expression levels on outcome of AML patients who were treated with decitabine. High MLL5 expressing AML patients have improved overall survival when treated with decitabine. In transformed murine cells, loss of Mll5 was associated with resistance to low-dose decitabine, less frequent promoter methylation, and reduced demethylation upon decitabine treatment. These data suggest a biological link between MLL5 expression and decitabine response involving regulation of DNA methylation. Leukemia cell model was generated by co-transfer of HOXA9 and MEIS1 into Mll5 wildtype or knockout mouse bone marrow cells. MeDIP was performed in Mll5+/+ HOXA9/MEIS1 and Mll5-/- HOXA9/MEIS1 leukemic cells, untreated or treated with 3-day exposure of 20 nM decitabine, triplicate for each condition. MeDIP-enriched DNA was amplified with the GenomePlex Complete Whole Genome Amplification (WGA) Kit (Sigma-Aldrich). DNA from three MeDIP and WGA of each cell type and treatment was pooled for subsequent microarray analysis. The enriched DNA and corresponding input genomic DNA was labeled, hybridized and scanned on Agilent custom mouse promoter microarrays (Agilent-025976 AP_1M_Custom_CH3, assembly build mm9). The methylation value of individual probes was defined by the signal intensity ratio of MeDIP DNA (Cy3) compared to input DNA (Cy5) . Methylated DNA immunoprecipitation coupled with Agilent mouse promoter CpG arrays (MeDIP-chip)