Targeting of FLT3-ITD kinase contributes to high selectivity of imidazoacridinone C-1311 against FLT3-activated leukemia cells
Abstract
Drugs targeting receptor tyrosine kinase FLT3 are of particular interest since activating FLT3-internal tandem duplication (ITD) mutations abundantly occur in fatal acute myeloid leukemias (AMLs). Imidazoacridinone C-1311, a DNA-reactive inhibitor of topoisomerase II, has been previously shown to be a potent and selective inhibitor of recombinant FLT3. Here, we expand those findings by studying its effect on leukemia cells with wild-type FLT3, FLT3-ITD mutant and no FLT3 receptor. While brief C-1311 exposure blocked wild-type and FLT3-ITD activity, profound and sustained inhibition was achieved only for FLT3-ITD mutants. C-1311 inhibited FLT3 downstream pathways (MAPK and AKT) independent of FLT3 status, yet translation to decreased viability was significant in FLT3-ITD cells. RNA interference against FLT3-ITD reduced cytotoxic effect and apoptosis induced by C-1311, indicating selective inhibition of FLT3-ITD crucial for high efficacy of drug against activated leukemia cells. Cellular responses in treated FLT3-ITD mutants included G1 and G2/M phase arrest, moderate inhibition of Bcl-2, caspase-3 activation, PARP cleavage, and depolarization of mitochondria. Consistent with selective decrease in FLT3-ITD activity, C-1311 remarkably reduced antiapoptotic survivin mRNA and protein expression, correlating well with enhanced apoptosis of FLT3-ITD cells. No survivin decrease and respectively lower level of apoptosis was found in wild-type and null-FLT3 cells. Combination of C-1311 with cytarabine or doxorubicin again showed distinct synergistic activity in FLT3-ITD-positive cells. The ability of C-1311 to selectively target constitutively active FLT3, suggests a favorable therapeutic index for AML carrying FLT3-ITD mutations. Thus further preclinical and clinical studies addressing its potency against FLT3-ITD kinase is well justified.
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- Category:
- Articles
- Type:
- artykuł w czasopiśmie wyróżnionym w JCR
- Published in:
-
BIOCHEMICAL PHARMACOLOGY
no. 95,
edition 4,
pages 238 - 252,
ISSN: 0006-2952 - Language:
- English
- Publication year:
- 2015
- Bibliographic description:
- Skwarska A., Augustin E., Beffinger M., Wojtczyk A., Konicz S., Laskowska K., Polewska J.: Targeting of FLT3-ITD kinase contributes to high selectivity of imidazoacridinone C-1311 against FLT3-activated leukemia cells// BIOCHEMICAL PHARMACOLOGY. -Vol. 95, iss. 4 (2015), s.238-252
- DOI:
- Digital Object Identifier (open in new tab) 10.1016/j.bcp.2015.04.006
- Verified by:
- Gdańsk University of Technology
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