title: Inhibition of DNA damage repair by artificial activation of PARP with siDNA.
abstract: One of the major early steps of repair is the recruitment of repair proteins at the damage site, and this is coordinated by a cascade of modifications controlled by phosphatidylinositol 3-kinase-related kinases and/or poly (ADP-ribose) polymerase (PARP). We used short interfering DNA molecules mimicking double-strand breaks (called Dbait) or single-strand breaks (called Pbait) to promote DNA-dependent protein kinase (DNA-PK) and PARP activation. Dbait bound and induced both PARP and DNA-PK activities, whereas Pbait acts only on PARP. Therefore, comparative study of the two molecules allows analysis of the respective roles of the two signaling pathways: both recruit proteins involved in single-strand break repair (PARP, XRCC1 and PCNA) and prevent their recruitment at chromosomal damage. Dbait, but not Pbait, also inhibits recruitment of proteins involved in double-strand break repair (53BP1, NBS1, RAD51 and DNA-PK). By these ways, Pbait and Dbait disorganize DNA repair, thereby sensitizing cells to various treatments. Single-strand breaks repair inhibition depends on direct trapping of the main proteins on both molecules. Double-strand breaks repair inhibition may be indirect, resulting from the phosphorylation of double-strand breaks repair proteins and chromatin targets by activated DNA-PK. The DNA repair inhibition by both molecules is confirmed by their synthetic lethality with BRCA mutations.
authors.affiliation: Institut Curie, CNRS-UMR3347, INSERM-U1021, 91405 Orsay, France, DNA Therapeutics, Génopole, 91000 Evry, France, Institut Curie, CNRS-UMR3348, Plateforme PICT-IBiSA, 91405 Orsay, France and Museum National d'Histoire Naturelle, USM503, 75231 Paris, France.
authors.forename: Amelie
authors.initials: A
authors.lastname: Croset
authors.forename: Fabrice P
authors.initials: FP
authors.lastname: Cordelières
authors.forename: Nathalie
authors.initials: N
authors.lastname: Berthault
authors.forename: Cyril
authors.initials: C
authors.lastname: Buhler
authors.forename: Jian-Sheng
authors.initials: JS
authors.lastname: Sun
authors.forename: Maria
authors.initials: M
authors.lastname: Quanz
authors.forename: Marie
authors.initials: M
authors.lastname: Dutreix
mesh_terms: D024682:BRCA2 Protein / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001562:Benzimidazoles / Q000494:pharmacology; D053903:DNA Breaks, Double-Stranded; D004249:DNA Damage; D004260:DNA Repair; D051747:DNA-Activated Protein Kinase / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D015894:Genome, Human; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D000071137:Poly (ADP-Ribose) Polymerase-1; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D024682:BRCA2 Protein; C551750:BRCA2 protein, human; D001562:Benzimidazoles; D009687:Nuclear Proteins; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; C521013:veliparib; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human