New research project

DNMT3A somatic missense mutations are frequently observed in AML, but their precise role in tumorigenesis is unclear. DNMT3A interacts with DNA sequence-specifically, binds nucleosomes and 3 different histone PTMs. These multivalent chromatin interactions make it difficult to identify the specific molecular effect of DNMT3A cancer mutations. Current methods allow to determine in vitro and cellular activity of DNMT3A mutants and to study methylomes of cancer cells, but all these approaches have limitations. In this project, we aim to investigate DNMT3A activity on a physiological substrate with all human genomic DNA sequences, nucleosomes and histone PTMs. For this we will use demethylated chromatin isolated from human cell lines after treatment with a DNA methyltransferase inhibitor as substrate for semi-in vitro DNA methylation assays. These assays will fill in the gap between pure in vitro and in cellulo approaches and allow us to investigate the effects of DNMT3A somatic cancer mutants on the methylation of human chromatin. Our data will uncover how DNMT3A mutants could generate aberrant DNA methylation patterns in cells, identify regions with altered methylation and novel downstream target gene candidates.