NFATc1 as a therapeutic target in FLT3-ITD-positive AML

Area of Science:

• Oncology
• Molecular Biology
• Hematology

Background:

• Internal tandem duplications (ITD) in the Fms-related tyrosine kinase 3 receptor (FLT3) are linked to poor prognosis in acute myeloid leukemia (AML).
• FLT3 inhibitors show limited long-term efficacy, necessitating research into resistance mechanisms and novel therapeutic strategies.

Purpose of the Study:

• To investigate the role of nuclear factor of activated T cells, NFATc1, in mediating resistance to FLT3 inhibitors in AML.
• To evaluate the potential of NFAT inhibition as a strategy to overcome sorafenib resistance in FLT3-ITD+ AML.

Main Methods:

• Assessed NFATc1 expression in FLT3-ITD+ AML.
• Utilized inducible short hairpin RNA for NFATc1 knockdown.
• Employed pharmacological NFAT inhibition with cyclosporine A (CsA) and VIVIT.
• Investigated the impact of NFATc1 modulation on sorafenib-induced apoptosis in FLT3-ITD+ cells and primary AML samples.
• Analyzed clinical data of FLT3-ITD+ AML patients treated with CsA.

Main Results:

• NFATc1 was frequently overexpressed in FLT3-ITD+ AML.
• NFATc1 knockdown or inhibition with CsA/VIVIT enhanced sorafenib-induced apoptosis in FLT3-ITD+ cells.
• CsA effectively overcame sorafenib resistance in FLT3-ITD+ cell lines and primary AML.
• Constitutive nuclear NFATc1 expression conferred robust sorafenib resistance.
• FLT3-ITD+ AML patients receiving CsA showed superior outcomes compared to FLT3-WT AML patients.

Conclusions:

• NFATc1 is identified as a novel mediator of sorafenib resistance in FLT3-ITD+ AML.
• Inhibition of NFATc1 by CsA counteracts sorafenib resistance and may improve treatment outcomes in AML.
• Targeting NFATc1 presents a promising therapeutic strategy for overcoming FLT3 inhibitor resistance in AML.