title: Absolute quantification of cell-free microRNAs in cancer patients.
abstract: The hypothesis to use microRNAs (miRNAs) circulating in the blood as cancer biomarkers was formulated some years ago based on promising initial results. After some exciting discoveries, however, it became evident that the accurate quantification of cell-free miRNAs was more challenging than expected. Difficulties were linked to the strong impact that many, if not all, pre- and post- analytical variables have on the final results. In this study, we used currently available high-throughput technologies to identify miRNAs present in plasma and serum of patients with breast, colorectal, lung, thyroid and melanoma tumors, and healthy controls. Then, we assessed the absolute level of nine different miRNAs (miR-320a, miR-21-5p, miR-378a-3p, miR-181a-5p, miR-3156-5p, miR-2110, miR-125a-5p, miR-425-5p, miR-766-3p) in 207 samples from healthy controls and cancer patients using droplet digital PCR (ddPCR) technology. We identified miRNAs specifically modulated in one or more cancer types, according to tissue source. The significant reduction of miR-181a-5p levels in breast cancer patients serum was further validated using two independent cohorts, one from Italy (n = 70) and one from US (n = 90), with AUC 0.66 and 0.73 respectively. This study finally powers the use of cell-free miRNAs as cancer biomarkers and propose miR-181a-5p as a diagnostic breast cancer biomarker.
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.|Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Ferracin
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Lupini
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Salamon
authors.affiliation: Section of Hematology, S. Anna University Hospital, Ferrara, Italy.|Department of Medical Sciences, University of Ferrara, Ferrara, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Saccenti
authors.affiliation: Breast Unit, S. Anna University Hospital, Ferrara, Italy.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Zanzi
authors.affiliation: Clinical Oncology Unit, S. Anna University Hospital, Ferrara, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rocchi
authors.affiliation: Clinical Oncology Unit, S. Anna University Hospital, Ferrara, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Da Ros
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.|Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Zagatti
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Gentian
authors.initials: G
authors.lastname: Musa
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Cristian
authors.initials: C
authors.lastname: Bassi
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Mangolini
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.|Section of General and Thoracic Surgery, S. Anna University Hospital, Ferrara, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Cavallesco
authors.affiliation: Clinical Oncology Unit, S. Anna University Hospital, Ferrara, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Frassoldati
authors.affiliation: Department of Medical Sciences, University of Ferrara, Ferrara, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Volpato
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.|Breast Unit, S. Anna University Hospital, Ferrara, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Carcoforo
authors.affiliation: Department of Surgery, Mercy Hospital - OKC, Oklahoma City, OK, USA.
authors.forename: Alan B
authors.initials: AB
authors.lastname: Hollingsworth
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.|Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Negrini
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs
keywords: breast cancer; cancer biomarkers; cell-free microRNA; droplet digital PCR