title: Sequence dependence of electron-induced DNA strand breakage revealed by DNA nanoarrays.
abstract: The electronic structure of DNA is determined by its nucleotide sequence, which is for instance exploited in molecular electronics. Here we demonstrate that also the DNA strand breakage induced by low-energy electrons (18 eV) depends on the nucleotide sequence. To determine the absolute cross sections for electron induced single strand breaks in specific 13 mer oligonucleotides we used atomic force microscopy analysis of DNA origami based DNA nanoarrays. We investigated the DNA sequences 5'-TT(XYX)3TT with X = A, G, C and Y = T, BrU 5-bromouracil and found absolute strand break cross sections between 2.66 · 10(-14) cm(2) and 7.06 · 10(-14) cm(2). The highest cross section was found for 5'-TT(ATA)3TT and 5'-TT(ABrUA)3TT, respectively. BrU is a radiosensitizer, which was discussed to be used in cancer radiation therapy. The replacement of T by BrU into the investigated DNA sequences leads to a slight increase of the absolute strand break cross sections resulting in sequence-dependent enhancement factors between 1.14 and 1.66. Nevertheless, the variation of strand break cross sections due to the specific nucleotide sequence is considerably higher. Thus, the present results suggest the development of targeted radiosensitizers for cancer radiation therapy.
authors.affiliation: 1] Interdisciplinary Nanoscience Center (iNANO) and Danish National Research Foundation: Centre for DNA Nanotechnology (CDNA), Aarhus University, 8000 Aarhus C, Denmark [2] Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
authors.forename: Adrian
authors.initials: A
authors.lastname: Keller
authors.affiliation: Institute of Chemistry - Physical Chemistry, University of Potsdam, Potsdam, Germany.
authors.forename: Jenny
authors.initials: J
authors.lastname: Rackwitz
authors.affiliation: Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors.forename: Emilie
authors.initials: E
authors.lastname: Cauët
authors.affiliation: Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors.forename: Jacques
authors.initials: J
authors.lastname: Liévin
authors.affiliation: Institute of Chemistry - Physical Chemistry, University of Potsdam, Potsdam, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Körzdörfer
authors.affiliation: Center of Advanced Research in Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry, 700487 Iasi, Romania.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Rotaru
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO) and Danish National Research Foundation: Centre for DNA Nanotechnology (CDNA), Aarhus University, 8000 Aarhus C, Denmark.
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Gothelf
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO) and Danish National Research Foundation: Centre for DNA Nanotechnology (CDNA), Aarhus University, 8000 Aarhus C, Denmark.
authors.forename: Flemming
authors.initials: F
authors.lastname: Besenbacher
authors.affiliation: 1] Interdisciplinary Nanoscience Center (iNANO) and Danish National Research Foundation: Centre for DNA Nanotechnology (CDNA), Aarhus University, 8000 Aarhus C, Denmark [2] Institute of Chemistry - Physical Chemistry, University of Potsdam, Potsdam, Germany [3] BAM Federal Institute of Materials Research and Testing, Berlin, Germany.
authors.forename: Ilko
authors.initials: I
authors.lastname: Bald
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D053960:DNA Breaks / Q000528:radiation effects*; D004583:Electrons / Q000009:adverse effects*; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D004247:DNA