Subcellular localization of the FLT3-ITD oncogene plays a significant role in the production of NOX- and p22phox-derived reactive oxygen species in acute myeloid leukemia

Loading...
Thumbnail Image
Files
1748.pdf(1.04 MB)
Accepted Version
Date
2017-11-11
Authors
Moloney, Jennifer N.
Stanicka, Joanna
Cotter, Thomas G.
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Ltd.
Research Projects
Organizational Units
Journal Issue
Abstract
Internal tandem duplication of the juxtamembrane domain of FMS-like tyrosine kinase 3 (FLT3-ITD) receptor is the most prevalent FLT3 mutation accounting for 20% of acute myeloid leukemia (AML) patients. FLT3-ITD mutation results in ligand-independent constitutive activation of the receptor at the plasma membrane and ‘impaired trafficking’ of the receptor in compartments of the endomembrane system, such as the endoplasmic reticulum (ER). FLT3-ITD expressing cells have been shown to generate increased levels of reactive oxygen species (ROS), in particular NADPH oxidase (NOX)-generated ROS which act as pro-survival signals. The purpose of this study is to investigate FLT3-ITD production of ROS at the plasma membrane and ER in the FLT3-ITD expressing AML cell line MV4-11. Receptor trafficking inhibitors; Tunicamycin and Brefeldin A induce ER retention of FLT3-ITD, resulting in a decrease in protein expression of NOX4 and its partner protein p22phox, thus demonstrating the critical importance of FLT3-ITD localization for the generation of pro-survival ROS. NOX-generated ROS contribute to total endogenous hydrogen peroxide (H2O2) in AML as quantified by flow cytometry using the cell-permeable H2O2-probe Peroxy Orange 1 (PO1). We found that PI3K/AKT signaling only occurs when FLT3-ITD is expressed at the plasma membrane and is required for the production of NOX-generated ROS. ER retention of FLT3-ITD resulted in NOX4 deglycosylation and p22phox protein degradation.
Description
Keywords
Acute myeloid leukemia , FLT3-ITD , Oncogene , NADPH oxidase , p22 , Pro-survival reactive oxygen species
Citation
Moloney, J. N., Stanicka, J. and Cotter, T. G. (2016) 'Subcellular localization of the FLT3-ITD oncogene plays a significant role in the production of NOX- and p22phox-derived reactive oxygen species in acute myeloid leukemia', Leukemia Research, 52, pp. 34-42. doi:10.1016/j.leukres.2016.11.006