Previously, DEK expression was reported to be 10-fold lower in mature hematopoietic cells as compared to immature CD34 positive cells [6]. Since four studies analyzing DEK expression in leukemia were inconclusive the aim of this study was to characterize DEK expression in a large multi-center cohort of AML cases. As an initial reference, DEK expression was profiled during normal hematopoietic differentiation of the myeloid lineage in both human

and mouse using the Hemaexplorer database [31]. Analysis of DEK expression in primary AML samples was compared to normal bone marrow using both the Microarray Innovations in Leukemia (MILE) study [32] and acute myeloid leukemia dataset (LAML) from Ley et al [33] and mapped back to the normal hematopoietic expression. This was validated and confirmed in independent cohorts of primary AML patient samples at the RNA level by

click here qRT-PCR and at the protein level by immunohistochemistry using a newly assembled AML-specific tissue microarray (TMA). Finally, DEK expression was evaluated in relation to overall survival of AML patients and prognostic relevance using the LAML dataset [33]. DEK expression during normal hematopoiesis in both human and murine models was assessed RO4929097 cost using the publicly available Hemaexplorer database (http://servers.binf.ku.dk/hemaexplorer) [31], which enabled DEK gene expression levels to be profiled in hematopoietic cells during different maturation stages based on curated microarray data. The data was analyzed using the Partek Genomics Suite v 6.6 (Partek Inc., Missouri, USA) Bay 11-7085 and GraphPad Prism 5 (GraphPad, California, USA).

All data was normalized and batch corrected. DEK expression levels in AML compared to normal bone marrow (NBM) were determined using the Affymetrix CEL files generated for the MILE study database GSE13204 [32] and the LAML dataset [33], and analyzed using Partek Genomics Suite v 6.6. ANOVA was carried out on microarray results by comparing DEK expression in NBM controls to leukemia in addition to comparison tests between NBM and specific AML subtypes. Overall patient survival associated with DEK expression was analyzed using the alternative microarray dataset LAML generated as part of The Cancer Genome Atlas (TCGA; [33]). RNA was extracted and purified from samples of 30 patients with AML (OREC 08/NIR01/9). Synthesis of cDNA was performed using the High-Capacity cDNA reverse transcription (RT) kit according to the manufacturer’s protocol (Applied Biosystems, California, USA). RT was performed using the Veriti Thermal Cycler (Applied Biosystems) at the following conditions: 25 °C for 10 min, 37 °C for 2 h, 85 °C for 5 min and a 4 °C hold period. All qRT-PCR was executed using the SYBR green mastermix (Roche) on the 7900HT Fast Real-time PCR platform (Applied Biosystems) with standard cycling conditions (95 °C for 10 min followed by 40 cycles of 95 °C for 10 s and 60 °C for 30 s).