title: MiTF regulates cellular response to reactive oxygen species through transcriptional regulation of APE-1/Ref-1.
abstract: Microphthalmia-associated transcription factor (MiTF) is a key transcription factor for melanocyte lineage survival. Most previous work on this gene has been focused on its role in development. A role in carcinogenesis has emerged recently, but the mechanism is unclear. We classified melanoma cells into MiTF-positive and -negative groups and explored the function of MiTF in regulating cellular responses to reactive oxygen species (ROS). The MiTF-positive melanoma cell lines accumulated high levels of apurinic/apyrimidinic endonuclease (APE-1/Ref-1, redox effector-1), a key redox sensor and DNA endonuclease critical for oxidative DNA damage repair. We demonstrate that APE-1 is a transcriptional target for MiTF. Knocking down MiTF led to reduced APE-1 protein accumulation, as well as abolished induction of APE-1 by ROS. MiTF-negative melanoma cells survived more poorly under ROS stress than the MiTF-positive cells based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Trypan blue staining. Overexpression of APE-1 partially rescued ROS-induced cell death when MiTF was depleted. We conclude that MiTF regulates cellular response to ROS by regulation of APE-1, and this may provide a mechanism of how MiTF is involved in melanoma carcinogenesis.
authors.affiliation: Department of Medicine, Chao Family Comprehensive Cancer Center, Irvine School of Medicine, University of California, Orange, California 92868, USA. liufe@uci.edu
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Fu
authors.forename: Frank L
authors.initials: FL
authors.lastname: Meyskens
mesh_terms: D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics* / Q000378:metabolism; D024721:E-Box Elements / Q000502:physiology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008544:Melanocytes / Q000166:cytology / Q000502:physiology*; D008545:Melanoma / Q000503:physiopathology; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D010766:Phosphorylation / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012867:Skin / Q000166:cytology; D012878:Skin Neoplasms / Q000503:physiopathology; D014158:Transcription, Genetic / Q000502:physiology; D015854:Up-Regulation / Q000502:physiology
chemical_list: C497234:MITF protein, human; D051739:Microphthalmia-Associated Transcription Factor; D016877:Oxidants; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase