The high Nrf2 expression in human acute myeloid leukemia is driven by NF-κB and underlies its chemo-resistance

SA Rushworth, L Zaitseva, MY Murray, NM Shah, KM Bowles, DJ Macewan

Research output: Contribution to journalArticlepeer-review

165 Citations (Scopus)

Abstract

NF-E2-related factor 2 (Nrf2) transcription factor regulates a range of cytoprotective transcriptional responses, preventing further cellular injury by removing biochemical damage and renewing tissue. Here we show that acute myeloid leukemia (AML) cells possess greater constitutive nuclear levels of Nrf2 than normal control CD34(+) cells because of an imbalance between mRNA expression levels of Nrf2 and its inhibitor Keap1 but not through their somatic mutation. Elevated Nrf2 was reduced by NF-κB inhibitors. Using promoter assays, ChIP and siRNA knockdown, we demonstrated NF-κB subunits p50 and p65 induce transcription of Nrf2 in AML cells at a specific promoter κB-site and that long-term lentiviral miRNA-knockdown of Nrf2 significantly reduced clonogenicity of AML patient cells and improved their chemotherapeutic responsiveness. Normal physiologic Nrf2 protects cells from damage, but here we have exposed aberrant continuous nuclear activation of Nrf2 in AML that allows cell survival, even against cytotoxic chemotherapeutics. We show for the first time that Nrf2, an important regulator of several biologic processes involved in the progression of cancer, has abnormal NF-κB-driven constitutive expression in AML. Such a mechanism allows for a greater cytoprotective response in human AML cells and encourages their evasion of chemotherapy-induced cytotoxicity, which is necessary for improved clinical outcomes.
Original languageEnglish
Pages (from-to)5188-5198
Number of pages11
JournalBlood
Volume120
Issue number26
DOIs
Publication statusPublished - 20 Dec 2012

Keywords

  • Adult
  • Aged
  • Aged, 80 and over
  • Drug Resistance, Neoplasm
  • Female
  • Gene Expression Regulation, Leukemic
  • HL-60 Cells
  • Humans
  • Leukemia, Myeloid, Acute
  • Male
  • Middle Aged
  • NF-E2-Related Factor 2
  • NF-kappa B
  • Tumor Cells, Cultured
  • U937 Cells
  • Up-Regulation

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