Impact of MLL5 expression on decitabine efficacy and DNA methylation in acute myeloid leukemia

ABSTRACT: 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)

ORGANISM(S): Mus musculus

SUBMITTER: Michael Heuser 

PROVIDER: E-GEOD-52199 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress