Although FLT3 mutations are essentially found in myeloid-lineage leukemia cells, a high level of FLT3 expression was recently observed in MLL gene-rearranged acute lymphoblastic leukemia without FLT3 mutations.
We will highlight the role of FLT3 in hematopoiesis, and how when activated, it may play a role in the development of acute myeloid or acute lymphoblastic leukemia.
Fms-like tyrosine kinase 3 (FLT3) is highly expressed in acute lymphoblastic leukemia with the mixed-lineage leukemia (MLL) gene rearrangement refractory to chemotherapy.
To further explore the efficacy of targeted therapies, we demonstrate that T-ALL cell lines transfected with FLT3 expression constructs were particularly sensitive to tyrosine kinase inhibitors.
The incorporation of ABL kinase inhibitors into acute lymphoblastic leukemia management should serve as a model for incorporation of FLT3-targeted agents into clinical care.
The present study employed single cell mutation analysis to evaluate the FLT3-ITD status in newly diagnosed acute myeloid leukemia (n = 5) and acute lymphocytic leukemia (n = 3) patients.
Two of 25 ALL patients (8%) showed a mutated band of FLT3-ITD mutation representing 12.5% of pediatric patients, and all the other ALL cases showed the absence of this mutation.
Our previous data demonstrated specific up-regulation of miR-155 in FLT3-ITD+ AML. miR-155 is known to be directly implicated in normal hematopoiesis and in some pathologies such as myeloid hyperplasia and acute lymphoblastic leukemia.