title: Sensitive detection of cancer cells using light-mediated apta-PCR.
abstract: Apta-PCR is an ultrasensitive assay in which aptamers are exploited not only as biomolecular recognition elements, but also as reporter labels for amplification via real-time PCR. This methodology has been successfully applied to the detection of proteins, achieving limits of detection in the picomolar range. The introduction of caged aptamers that bear photo-labile groups, so called cages, at strategic positions so that their tertiary structure and thus their binding properties can be controlled by light, facilitates a more robust and attractive assay in terms of sample conservation and reusability. In this work, we report for the first time the use of caged aptamers for cell detection in an apta-PCR assay. Specifically, a sandwich format is used combining the capture of B-cells by an antibody with the specific detection of Burkitt's lymphoma cancer cells by a caged aptamer, acting as a reporter probe. Elution of the aptamer bound to the cancer cells is performed by light and the number of cells is then correlated with the amount of eluted caged aptamer using real-time PCR analysis. The reported technique shows an excellent sensitivity, achieving detection of as few as 77 cells, and due to the inherent robustness of the assay, this detection platform can be reused for further analyses, demonstrating potential applicability in proteomics and clinical diagnostics.
authors.affiliation: Department of Life and Medical Sciences, Program Unit Chemical Biology and Medicinal Chemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany; Nanobiotechnology & Bioanalysis Group, Departament d'Enginyeria Química, Universitat Rovira i Virgili, Avinguda Països Catalans 26, Tarragona 43007, Spain.
authors.forename: Laia
authors.initials: L
authors.lastname: Civit
authors.affiliation: Nanobiotechnology & Bioanalysis Group, Departament d'Enginyeria Química, Universitat Rovira i Virgili, Avinguda Països Catalans 26, Tarragona 43007, Spain.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pinto
authors.affiliation: Goethe University Frankfurt, Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Rodrigues-Correia
authors.affiliation: Goethe University Frankfurt, Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Straße 9, 60438 Frankfurt, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Heckel
authors.affiliation: Nanobiotechnology & Bioanalysis Group, Departament d'Enginyeria Química, Universitat Rovira i Virgili, Avinguda Països Catalans 26, Tarragona 43007, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain. Electronic address: ciara.osullivan@urv.cat.
authors.forename: Ciara K
authors.initials: CK
authors.lastname: O'Sullivan
authors.affiliation: Department of Life and Medical Sciences, Program Unit Chemical Biology and Medicinal Chemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany. Electronic address: gmayer@uni-bonn.de.
authors.forename: Günter
authors.initials: G
authors.lastname: Mayer
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D045744:Cell Line, Tumor; D054856:G-Quadruplexes; D006801:Humans; D055029:Inverted Repeat Sequences; D009369:Neoplasms / Q000175:diagnosis*; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide
keywords: Apta-PCR; Burkitt’s lymphoma cell detection; Caged aptamers; Photo-elution