Tyrosine kinase inhibitor-induced defects in DNA repair sensitize FLT3(ITD)-positive leukemia cells to PARP1 inhibitors

Item Type:	Article
Title:	Tyrosine kinase inhibitor-induced defects in DNA repair sensitize FLT3(ITD)-positive leukemia cells to PARP1 inhibitors
Creators Name:	Maifrede, S. and Nieborowska-Skorska, M. and Sullivan-Reed, K. and Dasgupta, Y. and Podszywalow-Bartnicka, P. and Le, B.V. and Solecka, M. and Lian, Z. and Belyaeva, E.A. and Nersesyan, A. and Machnicki, M.M. and Toma, M. and Chatain, N. and Rydzanicz, M. and Zhao, H. and Jelinek, J. and Piwocka, K. and Sliwinski, T. and Stoklosa, T. and Ploski, R. and Fischer, T. and Sykes, S.M. and Koschmieder, S. and Bullinger, L. and Valent, P. and Wasik, M.A. and Huang, J. and Skorski, T.
Abstract:	Mutations in FMS-like tyrosine kinase 3 (FLT3), such as internal tandem duplications (ITDs), can be found in up to 23% of patients with acute myeloid leukemia (AML) and confer a poor prognosis. Current treatment options for FLT3(ITD)-positive AMLs include genotoxic therapy and FLT3 inhibitors (FLT3i's), which are rarely curative. PARP1 inhibitors (PARP1i's) have been successfully applied to induce synthetic lethality in tumors harboring BRCA1/2 mutations and displaying homologous recombination (HR) deficiency. We show here that inhibition of FLT3(ITD) activity by the FLT3i AC220 caused downregulation of DNA repair proteins BRCA1, BRCA2, PALB2, RAD51, and LIG4, resulting in inhibition of 2 major DNA double-strand break (DSB) repair pathways, HR, and nonhomologous end-joining. PARP1i, olaparib, and BMN673 caused accumulation of lethal DSBs and cell death in AC220-treated FLT3(ITD)-positive leukemia cells, thus mimicking synthetic lethality. Moreover, the combination of FLT3i and PARP1i eliminated FLT3(ITD)-positive quiescent and proliferating leukemia stem cells, as well as leukemic progenitors, from human and mouse leukemia samples. Notably, the combination of AC220 and BMN673 significantly delayed disease onset and effectively reduced leukemia-initiating cells in an FLT3(ITD)-positive primary AML xenograft mouse model. In conclusion, we postulate that FLT3i-induced deficiencies in DSB repair pathways sensitize FLT3(ITD)-positive AML cells to synthetic lethality triggered by PARP1i's. Therefore, FLT3(ITD) could be used as a precision medicine marker for identifying AML patients that may benefit from a therapeutic regimen combining FLT3 and PARP1i's.
Keywords:	Antineoplastic Combined Chemotherapy Protocols, BRCA2 Protein, Benzothiazoles, Tumor Cell Line, DNA Ligase ATP, DNA Repair, Fanconi Anemia Complementation Group N Protein, Acute Myeloid Leukemia, Mutation, Phenylurea Compounds, Phthalazines, Piperazines, Poly (ADP-Ribose) Polymerase-1, Protein Kinase Inhibitors, Rad51 Recombinase, Tumor Suppressor Proteins, Xenograft Model Antitumor Assays, fms-Like Tyrosine Kinase 3, Animals, Mice
Source:	Blood
ISSN:	0006-4971
Publisher:	American Society of Hematology
Volume:	132
Number:	1
Page Range:	67-77
Date:	5 July 2018
Official Publication:	https://doi.org/10.1182/blood-2018-02-834895
PubMed:	View item in PubMed

Repository Staff Only: item control page