title: Molecular profiling of single circulating tumor cells with diagnostic intention.
abstract: Several hundred clinical trials currently explore the role of circulating tumor cell (CTC) analysis for therapy decisions, but assays are lacking for comprehensive molecular characterization of CTCs with diagnostic precision. We therefore combined a workflow for enrichment and isolation of pure CTCs with a non-random whole genome amplification method for single cells and applied it to 510 single CTCs and 189 leukocytes of 66 CTC-positive breast cancer patients. We defined a genome integrity index (GII) to identify single cells suited for molecular characterization by different molecular assays, such as diagnostic profiling of point mutations, gene amplifications and whole genomes of single cells. The reliability of > 90% for successful molecular analysis of high-quality clinical samples selected by the GII enabled assessing the molecular heterogeneity of single CTCs of metastatic breast cancer patients. We readily identified genomic disparity of potentially high relevance between primary tumors and CTCs. Microheterogeneity analysis among individual CTCs uncovered pre-existing cells resistant to ERBB2-targeted therapies suggesting ongoing microevolution at late-stage disease whose exploration may provide essential information for personalized treatment decisions and shed light into mechanisms of acquired drug resistance.
authors.affiliation: Project Group "Personalized Tumor Therapy", Fraunhofer Institute for Toxicology und Experimental Medicine, Regensburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Polzer
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Medoro
authors.affiliation: Experimental Medicine and Therapy Research, University of Regensburg, Regensburg, Germany.
authors.forename: Sophie
authors.initials: S
authors.lastname: Pasch
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Fontana
authors.affiliation: Division of Laboratory Medicine, European Institute of Oncology, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Zorzino
authors.affiliation: Department of Gynecology and Obstetrics, University Munich, Munich, Germany.
authors.forename: Aurelia
authors.initials: A
authors.lastname: Pestka
authors.affiliation: Department of Gynecology and Obstetrics, University Munich, Munich, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Andergassen
authors.affiliation: Department of Gynecology and Obstetrics, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Meier-Stiegen
authors.affiliation: Project Group "Personalized Tumor Therapy", Fraunhofer Institute for Toxicology und Experimental Medicine, Regensburg, Germany Experimental Medicine and Therapy Research, University of Regensburg, Regensburg, Germany.
authors.forename: Zbigniew T
authors.initials: ZT
authors.lastname: Czyz
authors.affiliation: Project Group "Personalized Tumor Therapy", Fraunhofer Institute for Toxicology und Experimental Medicine, Regensburg, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Alberter
authors.affiliation: Project Group "Personalized Tumor Therapy", Fraunhofer Institute for Toxicology und Experimental Medicine, Regensburg, Germany.
authors.forename: Steffi
authors.initials: S
authors.lastname: Treitschke
authors.affiliation: Experimental Medicine and Therapy Research, University of Regensburg, Regensburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schamberger
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Sergio
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Bregola
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Doffini
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Gianni
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Alex
authors.initials: A
authors.lastname: Calanca
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Signorini
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Bolognesi
authors.affiliation: Department of Pathology, University Erlangen, Erlangen, Germany.
authors.forename: Arndt
authors.initials: A
authors.lastname: Hartmann
authors.affiliation: Department of Gynecology and Obstetrics, University Erlangen, Erlangen, Germany.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Fasching
authors.affiliation: Division of Laboratory Medicine, European Institute of Oncology, Milan, Italy.
authors.forename: Maria T
authors.initials: MT
authors.lastname: Sandri
authors.affiliation: Department of Gynecology and Obstetrics, University Munich, Munich, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Rack
authors.affiliation: Department of Gynecology and Obstetrics, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Fehm
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Giorgini
authors.affiliation: Silicon Biosystems S.p.A., Bologna, Italy.
authors.forename: Nicolò
authors.initials: N
authors.lastname: Manaresi
authors.affiliation: Project Group "Personalized Tumor Therapy", Fraunhofer Institute for Toxicology und Experimental Medicine, Regensburg, Germany Experimental Medicine and Therapy Research, University of Regensburg, Regensburg, Germany christoph.klein@klinik.uni-regensburg.de.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Klein
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis*; D005260:Female; D023281:Genomics / Q000379:methods*; D006801:Humans; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D057089:Pathology, Molecular / Q000379:methods*; D059010:Single-Cell Analysis / Q000379:methods*
keywords: breast cancer; circulating tumor cells; metastasis; single cell analysis