Metabolic pathway for the universal fluorescent recognition of tumor cells

// Ana Fernandez-Carrascal 1, * , Manuel Garcia-Algar 1, * , Moritz Nazarenus 1 , Alicia Torres-Nunez 1 , Luca Guerrini 1 , Neus Feliu 2, 3 , Wolfgang J. Parak 3 , Eduardo Garcia-Rico 4 and Ramon A. Alvarez-Puebla 1, 5 1 Department of Physical Chemistry and EMaS, Universitat Rovira i Virgili, Tarragona, Spain 2 Karolinska Institutet, Stockholm, Sweden 3 Philipps-Universitat Marburg, Fachbereich Physik, Marburg, Germany 4 Department of Medical Oncology, Hospital Universitario HM Torrelodones, Torrelodones, Madrid, Spain 5 ICREA, Barcelona, Spain * These authors have contributed equally to this work Correspondence to: Eduardo Garcia-Rico, email: egarcia@hmhospitales.com Ramon A. Alvarez-Puebla, email: ramon.alvarez@urv.cat Keywords: circulating tumor cells, breast cancer, optical sensing, glucose uptake, hyperoxia Received: January 31, 2017      Accepted: June 05, 2017      Published: June 16, 2017 ABSTRACT Quantification of circulating tumor cells (CTCs) in blood samples from cancer patients is a non-invasive approach to monitoring the status of the disease. Most of the methods proposed in the recent years are phenomenological and rely on the use of antibodies labelled with fluorophores, magnetic particles, or immobilized on surfaces to capture the CTCs. Herein, we designed and optimized a method that employs a glucose analogue labelled with a fluorophore which takes advantage of the different metabolic pathways of cancer cells to discern them from normal ones. Notably, we demonstrate that fluorescence signal in tumor cells can be greatly maximized by applying hyperoxia conditions without damaging the cells. These results are demonstrated by means of confocal fluorescence and flow-cytometry measurements in peripheral blood mononuclear cells (PBMC) extracted after Ficoll of human blood samples and spiked with a known concentration of MCF-7 tumor cells.