Clinical Science (2018) 132 2029–2044 https://doi.org/10.1042/CS20180425 Received: 22 May 2018 Revised: 02 August 2018 Accepted: 13 August 2018 Accepted Manuscript Online: 17 August 2018 Version of Record published: 19 September 2018 Research Article Proteomic analysis of exosomes reveals an association between cell invasiveness and exosomal bioactivity on endothelial and mesenchymal cell migration in vitro Shayna Sharma 1 , Mona Alharbi 1 , Miharu Kobayashi 1 , Andrew Lai 1 , Dominic Guanzon 1 , Felipe Zu ˜ niga 2 , Valeska Ormazabal 3 , Carlos Palma 1 , Katherin Scholz-Romero 1 , Gregory E. Rice 1,4 , John D. Hooper 5 and Carlos Salomon 1,2,4 1 Exosome Biology Laboratory, Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research, Royal Brisbane and Women’s Hospital, The University of Queensland, Brisbane QLD 4029, Australia; 2 Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepci´ on, Concepci ´ on, Chile; 3 Faculty of Biological Sciences, Pharmacology Department, University of Concepcion, Concepcion, Chile; 4 Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Ochsner Clinic Foundation, New Orleans, LA, U.S.A.; 5 Mater Research Institute-University of Queensland, Translational Research Institute, Woolloongabba, Australia Correspondence: Carlos Salomon (c.salomongallo@uq.edu.au) Ovarian cancer has resulted in over 140 000 deaths reported annually worldwide. This is often attributed to cellular changes in the microenvironment, including increased migration of mesenchymal stem cells (MSCs) and endothelial cells (ECs) to facilitate metastasis. Re- cently, the ability of exosomes to communicate signals between cells (and promote cancer progression) has been established. In the present study, we explored the effect of exosomes on cells present in the tumour microenvironment. Exosomes were isolated from ovarian can- cer cells with different invasive capacity (high = SKOV-3 and low = OVCAR-3) by differential and buoyant density centrifugation and characterised using nanoparticle tracking analysis (NTA), Western blot, and EM. Exosome secretion was positively correlated with invasiveness of releasing cells. Proteomic analyses identifed common and unique proteins between ex- osomes from SKOV-3 and OVCAR-3 with gene ontology analyses revealing that these ex- osomes are involved in the regulation of cell migration. Since the tumour microenvironment contains multiple cell types, including MSCs and ECs, we examined the effect of these ex- osomes on MSC and EC migration. Exosomes promoted MSC and EC migration in a time- and concentration-dependent manner. The effect of exosomes isolated from SKOV-3 on cell migration was signifcantly higher compared with exosomes from OVCAR-3. Thus, we suggest that exosomes from ovarian cancer cells contain a specifc set of proteins that are representative of its cell of origin and the invasive capacity. Introduction Ovarian cancer is the most lethal gynaecological malignancy with most patients (75%) diagnosed at an advanced stage when the tumour has spread beyond the ovaries [1]. Cancer is a com- plex disease in which cells with tumorigenic traits (i.e. unregulated cell proliferation and resis- tance to cell death) require an ability to communicate with neighbouring cells to initiate and facilitate tumour progression. Although malignant cells may be the main driving force of tu- morigenesis, their interactions with the tumour microenvironment are critical for progression from a single tumour mass to distant metastases [2]. The tumour microenvironment is a com- plex milieu with multiple cell types (e.g. endothelial cells (ECs), immune cells and fibroblasts c  2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society 2029 Downloaded from https://portlandpress.com/clinsci/article-pdf/132/18/2029/449641/cs-2018-0425.pdf by guest on 12 June 2020