Induction of cytotoxicity and apoptosis in FLT3 mutant expressing cells using novel pyrimido cyanoacrylates and quinoline derivatives

Abstract

Background: Aberrant activation of FMS-like tyrosine kinase 3 (FLT3) is associated with acute myeloid leukemia (AML). Leukemic cells expressing constitutively active FLT3 mutants are resistance to the current cancer therapies (radiotherapy and chemotherapy); hence, there is an increased interest to identify new agents for the treatment of AML. The main aim of this study was evaluating cytotoxic effects of novel pyrimidocyanoacrylates and quinoline derivatives on FLT3 overexpressing cells.

Materials and methods: Five novel pyrimidocyanoacrylates & 2-chloro 3-carbaldehyde quinolone derivative compounds, E1QAC1, E1QAC2, E1QAC3, E1QAC4, and E1QAC5 were designed and synthesized at the Department of Chemistry, Faculty of Sciences, Ferdowsi University, Mashhad, Iran. FDC-P1 cells expressing human wild-type FLT3 (FD-FLT3-WT) and internal tandem duplication (ITD) mutants (FD-FLT3-ITD) used in this study. The cells maintained in DMEM medium supplemented with 10% fetal calf serum (FCS) and murine granulocyte-macrophage colony stimulating factor (mGM-CSF). Potency for induction of cytotoxicity (IC₅₀ value) and apoptosis was determined after treating the cells with concentration of the compounds by resazurin assay. Bax and Bcl2 activation status was also investigated by Western blot analysis.

Results: All the compounds had concentration-dependent effects on inhibition of cell proliferation and induction of apoptosis in both cell lines. E1QAC4 was the most potent compound for inhibition of cell proliferation (with IC50 value of 19 μM) and apoptosis induction in the FLT3-WT cells. However, FD-FLT3-ITD cells were nearly five-times more resistant to all the compounds (except than E1QAC2) that the FLT3-WT expressing cells. Western blotting results also showed that FD-FLT3-ITD cells had lower levels of Bax and higher levels of Bcl2 than the FD-FLT3-WT cells.

Conclusion: The five novel heterocyclic compounds (E1QAC1-5) had cytotoxic effects and induced apoptosis in FD-FLT3 cells. Therefore, it is worthwhile to consider them as potential lead compound for development of new therapeutic agents for AML patients.

Keywords: Autophosphorilation inhibition; Cell proliferation inhibition; FLT3 ligand; FMS-like tyrosine kinase 3; Small molecule inhibitors; Tyrosine kinase domain; Tyrosine kinase domain inhibitors.