title: NRF2-driven miR-125B1 and miR-29B1 transcriptional regulation controls a novel anti-apoptotic miRNA regulatory network for AML survival.
abstract: Transcription factor NRF2 is an important regulator of oxidative stress. It is involved in cancer progression, and has abnormal constitutive expression in acute myeloid leukaemia (AML). Posttranscriptional regulation by microRNAs (miRNAs) can affect the malignant phenotype of AML cells. In this study, we identified and characterised NRF2-regulated miRNAs in AML. An miRNA array identified miRNA expression level changes in response to NRF2 knockdown in AML cells. Further analysis of miRNAs concomitantly regulated by knockdown of the NRF2 inhibitor KEAP1 revealed the major candidate NRF2-mediated miRNAs in AML. We identified miR-125B to be upregulated and miR-29B to be downregulated by NRF2 in AML. Subsequent bioinformatic analysis identified putative NRF2 binding sites upstream of the miR-125B1 coding region and downstream of the mir-29B1 coding region. Chromatin immunoprecipitation analyses showed that NRF2 binds to these antioxidant response elements (AREs) located in the 5' untranslated regions of miR-125B and miR-29B. Finally, primary AML samples transfected with anti-miR-125B antagomiR or miR-29B mimic showed increased cell death responsiveness either alone or co-treated with standard AML chemotherapy. In summary, we find that NRF2 regulation of miR-125B and miR-29B acts to promote leukaemic cell survival, and their manipulation enhances AML responsiveness towards cytotoxic chemotherapeutics.
authors.affiliation: 1] Department of Molecular Haematology, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK [2] Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
authors.forename: N M
authors.initials: NM
authors.lastname: Shah
authors.affiliation: Department of Molecular Haematology, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK.
authors.forename: L
authors.initials: L
authors.lastname: Zaitseva
authors.affiliation: 1] Department of Molecular Haematology, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK [2] Department of Haematology, Norfolk and Norwich University Hospitals NHS Trust, Colney Lane, Norwich, UK.
authors.forename: K M
authors.initials: KM
authors.lastname: Bowles
authors.affiliation: Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: MacEwan
authors.affiliation: Department of Molecular Haematology, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Rushworth
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D001665:Binding Sites; D015536:Down-Regulation; D005260:Female; D053263:Gene Regulatory Networks; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000072019:Kelch-Like ECH-Associated Protein 1; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism / Q000473:pathology*; D008297:Male; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D051267:NF-E2-Related Factor 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000378:metabolism; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D034741:RNA, Small Interfering