Redox biology of myeloid leukaemias

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dc.check.embargoformatNot applicableen
dc.check.infoNo embargo requireden
dc.check.opt-outNoen
dc.check.reasonNo embargo requireden
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dc.contributor.advisorCotter, Thomas G.en
dc.contributor.authorStanicka, Joanna
dc.contributor.funderIrish Cancer Societyen
dc.date.accessioned2015-11-24T09:36:13Z
dc.date.available2015-11-24T09:36:13Z
dc.date.issued2014
dc.date.submitted2014
dc.description.abstractInternal tandem duplication of FMS-like receptor tyrosine kinase (FLT3-ITD) has been associated with an aggressive AML phenotype. FLT3-ITD expressing cell lines have been shown to generate increased levels of reactive oxygen species (ROS) and DNA double strand breaks (dsbs). However, the molecular basis of how FLT3-ITD-driven ROS leads to the aggressive form of AML is not clearly understood. Herein, we observe that the majority of H2O2 in FLT3-ITD-expressing MV4-11 cells colocalises to the endoplasmic reticulum (ER). Furthermore, ER localisation of ROS in MV4-11 cells corresponds to the localisation of p22phox, a small membrane-bound subunit of NOX complex. Furthermore, we show that 32D cells, a myeloblast-like cell line transfected with FLT3-ITD, possess higher steady protein levels of p22phox than their wild type FLT3 (FLT3-WT)-expressing counterparts. Moreover, the inhibition of FLT3-ITD, using various FLT3 tyrosine kinase inhibitors, uniformly results in a posttranslational downregulation of p22phox. We also show that depletion of NOX2 and NOX4 and p22phox, but not NOX1 proteins causes a reduction in endogenous H2O2 levels. We show that genomic instability induced by FLT3-ITD leads to an increase in nuclear levels of H2O2. The presence of H2O2 in the nucleus is largely reduced by inhibition of FLT3-ITD or NOX. Furthermore, similar results are also observed following siRNA knockdowns of p22phox or NOX4. We demonstrate that 32D cells transfected with FLT3-ITD have a higher level of DNA damage than 32D cells transfected with FLT3-WT. Additionally, inhibition of FLT3-ITD, p22phox and NOX knockdowns decrease the number of DNA dsbs. In summary, this study presents a novel mechanism of genomic instability generation in FLT3-ITD-expressing AML cells, whereby FLT3-ITD activates NOX complexes by stabilising p22phox. This in turn leads to elevated generation of ROS and DNA damage in these cells.en
dc.description.sponsorshipIrish Cancer Society (Research Scholarship Award CRS11STA)en
dc.description.statusNot peer revieweden
dc.description.versionAccepted Version
dc.format.mimetypeapplication/pdfen
dc.identifier.citationStanicka, J. 2014. Redox biology of myeloid leukaemias. PhD Thesis, University College Cork.en
dc.identifier.endpage214
dc.identifier.urihttps://hdl.handle.net/10468/2088
dc.language.isoenen
dc.publisherUniversity College Corken
dc.rights© 2014, Joanna Stanicka.en
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/en
dc.subjectRedoxen
dc.subjectNADPH oxidaseen
dc.subjectLeukaemiaen
dc.subjectROSen
dc.subjectFLT3en
dc.subjectGenomic instabilityen
dc.thesis.opt-outfalse
dc.titleRedox biology of myeloid leukaemiasen
dc.typeDoctoral thesisen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD (Science)en
ucc.workflow.supervisort.cotter@ucc.ie
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