title: Advantages of an optical nanosensor system for the mechanistic analysis of a novel topoisomerase I targeting drug: a case study.
abstract: The continuous need for the development of new small molecule anti-cancer drugs calls for easily accessible sensor systems for measuring the effect of vast numbers of new drugs on their potential cellular targets. Here we demonstrate the use of an optical DNA biosensor to unravel the inhibitory mechanism of a member of a new family of small molecule human topoisomerase I inhibitors, the so-called indeno-1,5-naphthyridines. By analysing human topoisomerase I catalysis on the biosensor in the absence or presence of added drug complemented with a few traditional assays, we demonstrate that the investigated member of the indeno-1,5-naphthyridine family inhibited human topoisomerase I activity by blocking enzyme-DNA dissociation. To our knowledge, this represents the first characterized example of a small molecule drug that inhibits a post-ligation step of catalysis. The elucidation of a completely new and rather surprising drug mechanism-of-action using an optical real time sensor highlights the value of this assay system in the search for new topoisomerase I targeting small molecule drugs.
authors.affiliation: Department of Molecular Biology and Genetics, C. F. Møllers Allé 3, Bldg 1131, Aarhus University, 8000 Aarhus C, Denmark. brk@mbg.au.dk.
authors.forename: Marie B
authors.identifier: http://orcid.org/0000-0003-1604-2937
authors.initials: MB
authors.lastname: Andersen
authors.affiliation: Department of Molecular Biology and Genetics, C. F. Møllers Allé 3, Bldg 1131, Aarhus University, 8000 Aarhus C, Denmark. brk@mbg.au.dk.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Tesauro
authors.affiliation: Departamento de Química Orgánica I, Facultad de Farmacia and Centro de Investigación Lascaray (Lascaray Research Center), Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Gonzalez
authors.affiliation: Department of Molecular Biology and Genetics, C. F. Møllers Allé 3, Bldg 1131, Aarhus University, 8000 Aarhus C, Denmark. brk@mbg.au.dk.
authors.forename: Emil L
authors.initials: EL
authors.lastname: Kristoffersen
authors.affiliation: Departamento de Química Orgánica I, Facultad de Farmacia and Centro de Investigación Lascaray (Lascaray Research Center), Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Alonso
authors.affiliation: Departamento de Química Orgánica I, Facultad de Farmacia and Centro de Investigación Lascaray (Lascaray Research Center), Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain.
authors.forename: Gloria
authors.initials: G
authors.lastname: Rubiales
authors.affiliation: Department of Chemistry, Langelandsgade 140, Aarhus University, 8000 Aarhus C, Denmark.
authors.forename: Andrea
authors.initials: A
authors.lastname: Coletta
authors.affiliation: Department of Molecular Biology and Genetics, C. F. Møllers Allé 3, Bldg 1131, Aarhus University, 8000 Aarhus C, Denmark. brk@mbg.au.dk.
authors.forename: Rikke
authors.initials: R
authors.lastname: Frøhlich
authors.affiliation: Department of Pathology, Nørrebrogade 44 building 18B, Aarhus University, Denmark.
authors.forename: Magnus
authors.initials: M
authors.lastname: Stougaard
authors.affiliation: Department of Molecular Biology and Genetics, C. F. Møllers Allé 3, Bldg 1131, Aarhus University, 8000 Aarhus C, Denmark. brk@mbg.au.dk and Interdisciplinary Nanoscience Center, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark and Division of Biomedical Engineering, Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China.
authors.forename: Yi-Ping
authors.identifier: http://orcid.org/0000-0002-2052-9724
authors.initials: YP
authors.lastname: Ho
authors.affiliation: Departamento de Química Orgánica I, Facultad de Farmacia and Centro de Investigación Lascaray (Lascaray Research Center), Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Palacios
authors.affiliation: Department of Molecular Biology and Genetics, C. F. Møllers Allé 3, Bldg 1131, Aarhus University, 8000 Aarhus C, Denmark. brk@mbg.au.dk.
authors.forename: Birgitta R
authors.initials: BR
authors.lastname: Knudsen
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D015374:Biosensing Techniques; D004247:DNA; D004264:DNA Topoisomerases, Type I / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D058990:Molecular Targeted Therapy; D009287:Naphthyridines / Q000494:pharmacology*; D059004:Topoisomerase I Inhibitors / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D009287:Naphthyridines; D059004:Topoisomerase I Inhibitors; C000612780:indeno(1,5)naphthyridine; D004247:DNA; D004264:DNA Topoisomerases, Type I