title: The catalytic topoisomerase II inhibitor dexrazoxane induces DNA breaks, ATF3 and the DNA damage response in cancer cells.
abstract: OBJECTIVE
  The catalytic topoisomerase II inhibitor dexrazoxane has been associated not only with improved cancer patient survival but also with secondary malignancies and reduced tumour response.
  
  
  METHODS
  We investigated the DNA damage response and the role of the activating transcription factor 3 (ATF3) accumulation in tumour cells exposed to dexrazoxane.
  
  
  RESULTS
  Dexrazoxane exposure induced topoisomerase IIα (TOP2A)-dependent cell death, γ-H2AX accumulation and increased tail moment in neutral comet assays. Dexrazoxane induced DNA damage responses, shown by enhanced levels of γ-H2AX/53BP1 foci, ATM (ataxia telangiectasia mutated), ATR (ATM and Rad3-related), Chk1 and Chk2 phosphorylation, and by p53 accumulation. Dexrazoxane-induced γ-H2AX accumulation was dependent on ATM. ATF3 protein was induced by dexrazoxane in a concentration- and time-dependent manner, which was abolished in TOP2A-depleted cells and in cells pre-incubated with ATM inhibitor. Knockdown of ATF3 gene expression by siRNA triggered apoptosis in control cells and diminished the p53 protein level in both control and dexrazoxane -treated cells. This was accompanied by increased γ-H2AX accumulation. ATF3 knockdown also delayed the repair of dexrazoxane -induced DNA double-strand breaks.
  
  
  CONCLUSIONS
  As with other TOP2A poisons, dexrazoxane induced DNA double-strand breaks followed by activation of the DNA damage response. The DNA damage-triggered ATF3 controlled p53 accumulation and generation of double-strand breaks and is proposed to serve as a switch between DNA damage and cell death following dexrazoxane treatment. These findings suggest a mechanistic explanation for the diverse clinical observations associated with dexrazoxane.
authors.affiliation: Institute of Pharmacology, Medical Center of the University Mainz, Mainz, Germany.
authors.forename: Shiwei
authors.initials: S
authors.lastname: Deng
authors.forename: Tiandong
authors.initials: T
authors.lastname: Yan
authors.forename: Teodora
authors.initials: T
authors.lastname: Nikolova
authors.forename: Dominik
authors.initials: D
authors.lastname: Fuhrmann
authors.forename: Andrea
authors.initials: A
authors.lastname: Nemecek
authors.forename: Ute
authors.initials: U
authors.lastname: Gödtel-Armbrust
authors.forename: Bernd
authors.initials: B
authors.lastname: Kaina
authors.forename: Leszek
authors.initials: L
authors.lastname: Wojnowski
mesh_terms: D051700:Activating Transcription Factor 3 / Q000235:genetics / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D045744:Cell Line, Tumor; D053903:DNA Breaks, Double-Stranded; D004250:DNA Topoisomerases, Type II / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D064730:Dexrazoxane / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005354:Fibrosarcoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006657:Histones / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D000075223:Poly-ADP-Ribose Binding Proteins; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D059005:Topoisomerase II Inhibitors / Q000494:pharmacology*; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D000071857:Tumor Suppressor p53-Binding Protein 1
chemical_list: C490449:ATF3 protein, human; D051700:Activating Transcription Factor 3; D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; C468783:H2AX protein, human; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; C495901:TP53 protein, human; C498301:TP53BP1 protein, human; D059005:Topoisomerase II Inhibitors; D016159:Tumor Suppressor Protein p53; D000071857:Tumor Suppressor p53-Binding Protein 1; D064730:Dexrazoxane; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D004250:DNA Topoisomerases, Type II; C000618811:TOP2A protein, human