Gene expression profiles of mono- and biallelic CEBPA mutations in cytogenetically normal AML

Purpose: CEBPA mutations are found as either biallelic (biCEBPA) or monoallelic (moCEBPA). We set out to explore whether the kind of CEBPA mutation is of prognostic relevance in cytogenetically normal AML (CN-AML). Patients and Methods: 467 homogeneously treated CN-AML patients were subdivided into moCEBPA, biCEBPA and wildtype (wt) CEBPA patients. The subgroups were analyzed for clinical parameters and for additional mutations in the NPM1, FLT3 and MLL genes. Furthermore, we obtained gene expression profiles (GEP) for a subgroup of 61 patients using oligonucleotide microarrays. 61 bone-marrow samples from CN-AML patients were analyzed using Affymetrix HG-U133 oligonucleotide microarrays (Affymetrix, Santa Clara, CA). Sample preparation, hybridization and image acquisition were performed according to standard Affymetrix protocols. Custom chip definition files based on the GeneAnnot database were used for data analysis (Ferrari et al, BMC Bioinformatics 8:446). The twilight algorithm was used to comapre gene expression profiles of patients with wildtype CEBPA and mono- and biallelic CEBPA mutations.