title: miRNA profiling of circulating EpCAM(+) extracellular vesicles: promising biomarkers of colorectal cancer.
abstract: Cancer cells secrete small membranous extracellular vesicles (EVs) into their microenvironment and circulation. These contain biomolecules, including proteins and microRNAs (miRNAs). Both circulating EVs and miRNAs have received much attention as biomarker candidates for non-invasive diagnostics. Here we describe a sensitive analytical method for isolation and subsequent miRNA profiling of epithelial-derived EVs from blood samples of patients with colorectal cancer (CRC). The epithelial-derived EVs were isolated by immunoaffinity-capture using the epithelial cell adhesion molecule (EpCAM) as marker. This approach mitigates some of the specificity issues observed in earlier studies of circulating miRNAs, in particular the negative influence of miRNAs released by erythrocytes, platelets and non-epithelial cells. By applying this method to 2 small-scale patient cohorts, we showed that blood plasma isolated from CRC patients prior to surgery contained elevated levels of 13 EpCAM(+)-EV miRNAs compared with healthy individuals. Upon surgical tumour removal, the plasma levels of 8 of these were reduced (miR-16-5p, miR-23a-3p, miR-23b-3p, miR-27a-3p, miR-27b-3p, miR-30b-5p, miR-30c-5p and miR-222-3p). These findings indicate that the miRNAs are of tumour origin and may have potential as non-invasive biomarkers for detection of CRC. This work describes a non-invasive blood-based method for sensitive detection of cancer with potential for clinical use in relation to diagnosis and screening. We used the method to study CRC; however, it is not restricted to this disease. It may in principle be used to study any cancer that release epithelial-derived EVs into circulation.
authors: Department of Molecular Medicine (MOMA), Aarhus University Hospital, Aarhus, Denmark.
authors: Marie Stampe
authors: MS
authors: Ostenfeld
authors: Department of Molecular Medicine (MOMA), Aarhus University Hospital, Aarhus, Denmark.
authors: Steffen Grann
authors: SG
authors: Jensen
authors: Department of Molecular Medicine (MOMA), Aarhus University Hospital, Aarhus, Denmark.
authors: Dennis Kjølhede
authors: DK
authors: Jeppesen
authors: Department of Molecular Medicine (MOMA), Aarhus University Hospital, Aarhus, Denmark.
authors: Lise-Lotte
authors: LL
authors: Christensen
authors: Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark.
authors: Stine Buch
authors: SB
authors: Thorsen
authors: Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark.
authors: Jan
authors: J
authors: Stenvang
authors: Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark.
authors: Michael Lykke
authors: ML
authors: Hvam
authors: Exiqon A/S, Vedbaek, Denmark.
authors: Anni
authors: A
authors: Thomsen
authors: Exiqon A/S, Vedbaek, Denmark.
authors: Peter
authors: P
authors: Mouritzen
authors: Department of Molecular Medicine (MOMA), Aarhus University Hospital, Aarhus, Denmark.
authors: Mads Heilskov
authors: MH
authors: Rasmussen
authors: Department of Surgical Gastroenterology 360, Hvidovre Hospital, Hvidovre, Denmark.
authors: Hans Jørgen
authors: HJ
authors: Nielsen
authors: Department of Molecular Medicine (MOMA), Aarhus University Hospital, Aarhus, Denmark.
authors: Torben Falck
authors: TF
authors: Ørntoft
authors: Department of Molecular Medicine (MOMA), Aarhus University Hospital, Aarhus, Denmark; cla@clin.au.dk.
authors: Claus Lindbjerg
authors: CL
authors: Andersen
keywords: blood-based CRC detection; colorectal cancer; epithelial-derived extracellular vesicles; immunoaffinity; isolation; microRNA; non-invasive biomarkers