title: Efficacy of the Combination of a PARP Inhibitor and UVC on Cancer Cells as Imaged by Focus Formation by the DNA Repair-related Protein 53BP1 Linked to Green Fluorescent Protein.
abstract: BACKGROUND
  The ability to image DNA repair in cancer cells after irradiation, as well as its inhibition by potential therapeutic agents, is important for the further development of effective cancer therapy. 53BP1 is a DNA repair protein that is overexpressed and forms foci when double-stranded DNA breaks occur in DNA.
  
  
  METHODS
  The re-localization of green fluorescent protein (GFP) fused to the chromatin-binding domain of 53BP1 to form foci was imaged after UVC irradiation of breast and pancreatic cancer cells expressing 53BP1-GFP using confocal microscopy.
  
  
  RESULTS
  During live-cell imaging, 53BP1-GFP focus formation was observed within 10 minutes after UVC irradiation. Most 53BP1 foci resolved by 100 minutes. To block UVC-induced double-strand break repair in cancer cells, poly(ADP-ribose) polymerase (PARP) was targeted with ABT-888 (veliparib). PARP inhibition markedly enhanced UVC-irradiation-induced persistence of 53BP1-foci, even beyond 100 minutes after UVC irradiation, and reduced proliferation of breast and pancreatic cancer cells.
  
  
  CONCLUSIONS
  Confocal microscopy of 53BP1-GFP is a powerful method for imaging UVC-induced DNA damage and repair, as well as inhibition of repair.
authors.affiliation: AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. Department of Orthopedic Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Tome
authors.affiliation: AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. Department of Orthopedic Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Fuminari
authors.initials: F
authors.lastname: Uehara
authors.affiliation: AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Miwa
authors.affiliation: AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A.
authors.forename: Shuya
authors.initials: S
authors.lastname: Yano
authors.affiliation: AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A.
authors.forename: Sumiyuki
authors.initials: S
authors.lastname: Mii
authors.affiliation: Ludwig Center for Metastasis Research, The University of Chicago, Chicago, IL, U.S.A.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Efimova
authors.affiliation: Department of Surgery, University of California, San Diego, CA, U.S.A.
authors.forename: Michael
authors.initials: M
authors.lastname: Bouvet
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kimura
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuchiya
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Fuminori
authors.initials: F
authors.lastname: Kanaya
authors.affiliation: AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. all@anticancer.com.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hoffman
mesh_terms: D001562:Benzimidazoles / Q000008:administration & dosage; D045744:Cell Line, Tumor; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage / Q000187:drug effects / Q000528:radiation effects; D004260:DNA Repair / Q000187:drug effects / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D049452:Green Fluorescent Proteins / Q000737:chemistry; D006801:Humans; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D010778:Photochemotherapy; D000071137:Poly (ADP-Ribose) Polymerase-1 / Q000096:biosynthesis / Q000235:genetics*; D000067856:Poly(ADP-ribose) Polymerase Inhibitors / Q000008:administration & dosage; D000071857:Tumor Suppressor p53-Binding Protein 1 / Q000096:biosynthesis / Q000235:genetics*; D014466:Ultraviolet Rays
chemical_list: D001562:Benzimidazoles; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; C498301:TP53BP1 protein, human; D000071857:Tumor Suppressor p53-Binding Protein 1; C521013:veliparib; D049452:Green Fluorescent Proteins; D000071137:Poly (ADP-Ribose) Polymerase-1
keywords: 53BP-1; ABT888; DNA damage; DNA repair; PARP; confocal microscopy; focus formation; green fluorescent protein; inhibition; real-time imaging