title: Monitoring the Rab27 associated exosome pathway using nanoparticle tracking analysis.
abstract: Exosomes are secreted by many cell types and display multiple biological functions. The ability to both rapidly detect and quantify exosomes in biological samples would assist in the screening of agents that interfere with their release, and which may therefore be of clinical relevance. Nanoparticle tracking analysis, which detects the size and concentration of exosomes, was used to monitor the inhibition of exosome secretion from MDA-MB-231 breast cancer cells expressing inhibitory RNA targeted for Rab27a, a known component of the exosome pathway. Inhibition of both Rab27a and Rab27b was observed, resulting in alterations to intracellular CD63+ compartments and the release of fewer exosomes into the culture medium, as determined by nanoparticle tracking analysis and confirmed by immunoblotting and protein quantification. These data show that nanoparticle tracking analysis can be used effectively and rapidly to monitor the disruption of exosome secretion.
authors.affiliation: School of Medicine, University of St Andrews, Fife, KY16 9TF, UK.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: School of Medicine, University of St Andrews, Fife, KY16 9TF, UK.
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Campbell
authors.affiliation: School of Medicine, University of St Andrews, Fife, KY16 9TF, UK.
authors.forename: John
authors.initials: J
authors.lastname: Lucocq
authors.affiliation: School of Medicine, University of St Andrews, Fife, KY16 9TF, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Riches
authors.affiliation: School of Medicine, University of St Andrews, Fife, KY16 9TF, UK. Electronic address: sjp10@st-andrews.ac.uk.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Powis
mesh_terms: D045744:Cell Line, Tumor; D055354:Exosomes / Q000378:metabolism*; D006801:Humans; D053758:Nanoparticles; D034741:RNA, Small Interfering; D055571:Secretory Pathway; D060149:Tetraspanin 30 / Q000235:genetics / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000075745:rab27 GTP-Binding Proteins
chemical_list: C554586:CD63 protein, human; D034741:RNA, Small Interfering; D060149:Tetraspanin 30; D000075745:rab27 GTP-Binding Proteins; C066694:RAB27A protein, human; C512960:Rab27B protein, human; D020691:rab GTP-Binding Proteins