Rabbit Anti-Human FLT3 (internal) Polyclonal antibody

Leukemic stem cells (LSCs) are a major cause of treatment failure and recurrence of acute myeloid leukemia (AML). Targeting LSC is essential to developing a potential cure for patients with relapsed/refractory AML. Here we investigated the effect of aryl hydrocarbon receptor (AhR) signaling on AML stem/progenitor proportion and examined the combined effect of AhR agonist and tyrosine kinase inhibitor. The AhR agonist, 6-formylindolo[3,2-b]carbazole (FICZ), significantly decreased the LSC proportion and clonogenicity and increased differentiation markers in AML primary cells. Synergistic/additive effects of FICZ and gilteritinib, FMS-like tyrosine kinase 3 (FLT3) inhibitor, were confirmed in AML cells with FLT3-ITD. We present evidence that combination of both agents inhibits FLT3 downstream molecules and degrades clonogenicity. Collectively, our results suggest that FICZ not only compels LSC differentiation, but also enhances the efficacy of gilteritinib when combined. Clinical application of this combined approach may pave a new therapeutic strategy for patients with FLT3 mutated AML.

Genetic mutations in acute myeloid leukaemia (AML) are assumed to occur in a sequential order; however, the predominant hierarchical roles of specific mutated genes have not been fully described. In this study, we aimed to determine the clonal involvement of the most frequent AML-associated mutations. Using a targeted sequencing panel for 18 genes, we traced changes and relative clonal contribution of mutations in 52 patients. We analysed 35 pairs of diagnosis and relapse samples, 27 pairs of primary samples and corresponding patient-derived xenografts, and 34 pairs of total leukocytes and corresponding isolated primitive cells or blast populations. In both relapse and xenografts, we observed conservation of main leukaemic clones and variability was limited to subclones with late-acquired mutations. AML evolution thus mainly involved modification of subclones while the clonal background remained unchanged. NPM1 mutations were identified as the most probable leukaemia-transformation lesion, remaining conserved in contrast to high variation of accompanying subclonal FLT3 and NRAS mutations. DNMT3A mutations represented the most stable mutations forming a preleukaemic background in most samples. Mutations in genes IDH1/2, TET2, RUNX1, ASXL1 and U2AF1 were detected both as preleukaemic and as subclonal lesions, suggesting a non-specific order of acquisition.