Flt3_ITD_insertion_mutagenesis

Acute myeloid leukaemia (AML) is the most common and aggressive form of hematologic malignancy in adults. Mutations in the gene for FMS-like tyrosine kinase 3 (FLT3) are found in more than 30% of AMLs of which more than 80% mutations are internal tandem duplications (FLT3-ITD) that confer a particularly poor prognosis. Albeit FLT3-ITD mutations are known to cooperate with class-defining AML mutations like the chimeric fusion genes and NPM1 mutations, 15-20% of the FLT3 mutations in AML do not synergize with any class-defining/driving AML mutations. In order to identify the altered molecular networks required for FLT3-ITD to progress to frank AML in the absence of known driving mutations, we performed a non-biased and random forward genome wide screen in Flt3-ITD sensitised transposon mediated insertional mutagenesis mice. We have crossed mice carrying a constitutive Flt3-ITD allele (Flt3ITD/+), a conditional Sleeping Beauty transposase (Rosa26flox-SB), the bi-functional GrOnc transposon and the hematopoietic stem cell (HSC)-active inducible recombinase transgene Mx1-Cre. The following cohorts were generated and aged: i) Mx1-Cre+;Flt3ITD/+ (FTD), ii) Mx1-Cre+;GrOnc+;Rosaflox-SB/+ (WT-IM), iii) Mx1-Cre+;Flt3ITD/+;GrOnc+;Rosaflox-SB/+ (FTD-IM), and iv) Flt3+/+, GrOnc- and Rosaflox-SB/+ single transgenics. Cells from bonemarrow, thymus and spleen were harvested and QiSeq was performed to identify common transposon insertions responsible for the AML establishment in the FTD-IM cohort.