Clonal evolution patterns in acute myeloid leukemia with NPM1 mutation (RNA-seq data set)

Mutations in the nucleophosmin 1 (NPM1) gene are considered founder mutations in the pathogenesis of acute myeloid leukemia (AML). To further characterize the genetic composition of NPM1 mutated (NPM1mut) AML, we assess mutation status of five recurrently mutated oncogenes (FLT3, DNMT3A, IDH1, IDH2, NRAS) in 129 paired NPM1mut samples obtained at diagnosis and relapse. We find a substantial shift in the genetic pattern from diagnosis to relapse including NPM1mut loss (n=11). To gain further insight into these NPM1mut loss cases, we perform whole exome sequencing (WES) and RNA-Seq. At the time of relapse, NPM1mut loss patients (pts) feature distinct mutational patterns that shared almost no somatic mutation with the corresponding diagnosis sample and impact different signaling pathways including loss of characteristic NPM1mut associated gene expression patterns. In contrast, profiles of pts with persistent NPM1mut at relapse are reflected by a high overlap of mutations between diagnosis and relapse. Thus, our findings confirm that relapse often originates from persistent leukemic clones, though NPM1mut loss cases suggest a second “de novo” or treatment-associated AML (tAML) as alternative cause of “relapse" in a subgroup of cases. Overall design: RNA-Seq was performed on paired (diagnosis and relapse) samples of NPM1mut loss and NPM1mut persistent patients using an Illumina HiSeq2000.