title: Bardoxolone-methyl inhibits migration and metabolism in MCF7 cells.
abstract: Bardoxolone-methyl (BAR) is reported to have anti-inflammatory, anti-proliferative and anti-fibrotic effects. BAR activates Nrf2 and may ameliorate oxidative stress through induction of antioxidant genes. However, off-target effects, probably concentration and NFkB-dependent, have limited the clinical use of BAR. Nrf2 regulates expression of antioxidant and mitochondrial genes and has been proposed as a target for both obesity and breast cancer. Therefore, we explored whether BAR can alter migration and proliferation in the MCF7 cell line and whether metabolic function is affected by BAR. Incubation with BAR caused a time-dependent migratory inhibition and an associated decrease in mitochondrial respiration. Both migratory and mitochondrial inhibition by BAR were further enhanced in the presence of fatty acids. In addition to the activation of Nrf2, BAR altered the expression of target mRNA GCLC and UCP1. After 24 h, BAR inhibited both glycolytic capacity, reserve (p < 0.05) and oxidative phosphorylation (p < 0.001) with an associated increase in mitochondrial ROS and loss of intracellular glutathione in MCF7 cells; however, impairment of mitochondrial activity was prevented by N-acetyl cysteine. The fatty acid, palmitate, increased mitochondrial ROS, impaired migration and oxidative phosphorylation but palmitate toxicity towards MCF7 could not be inhibited by N-acetyl cysteine suggesting that they exert effects through different pathways. BAR-activated AKT, induced DNA damage and inhibited cell proliferation. When the proteasome was inhibited, there was loss of BAR-mediated changes in p65 phosphorylation and SOD2 expression suggesting non-canonical NFkB signaling effects. These data suggest that BAR-induced ROS are important in inhibiting MCF7 migration and metabolism by negatively affecting glycolytic capacity and mitochondrial function.
authors.affiliation: a Life & Health Sciences , Aston University , Birmingham , UK.|b Helmy Institute of Medical Sciences, Zewail City of Science and Technology , Giza , Egypt.|c Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences , University of Toyama , Toyama , Japan.
authors.forename: Alaa
authors.initials: A
authors.lastname: Refaat
authors.affiliation: a Life & Health Sciences , Aston University , Birmingham , UK.
authors.forename: Chathyan
authors.initials: C
authors.lastname: Pararasa
authors.affiliation: a Life & Health Sciences , Aston University , Birmingham , UK.
authors.forename: Muhammed
authors.initials: M
authors.lastname: Arif
authors.affiliation: a Life & Health Sciences , Aston University , Birmingham , UK.
authors.forename: James E P
authors.initials: JE
authors.lastname: Brown
authors.affiliation: a Life & Health Sciences , Aston University , Birmingham , UK.
authors.forename: Amtul
authors.initials: A
authors.lastname: Carmichael
authors.affiliation: b Helmy Institute of Medical Sciences, Zewail City of Science and Technology , Giza , Egypt.
authors.forename: Sameh S
authors.initials: SS
authors.lastname: Ali
authors.affiliation: c Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences , University of Toyama , Toyama , Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakurai
authors.affiliation: a Life & Health Sciences , Aston University , Birmingham , UK.|d Faculty of Health and Medical Sciences , University of Surrey , Guildford , UK.
authors.forename: Helen R
authors.initials: HR
authors.lastname: Griffiths
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D061986:MCF-7 Cells; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000975:Antioxidants; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D009828:Oleanolic Acid; C445068:bardoxolone methyl; D005978:Glutathione
keywords: Breast cancer; glutathione; glycolysis; mitochondria; palmitate; reactive oxygen species