title: Proteomic analysis of exosomes from nasopharyngeal carcinoma cell identifies intercellular transfer of angiogenic proteins.
abstract: Exosomes, a group of secreted extracellular nanovesicles containing genetic materials and signaling molecules, play a critical role in intercellular communication. During tumorigenesis, exosomes have been demonstrated to promote tumor angiogenesis and metastasis while their biological functions in nasopharyngeal carcinoma (NPC) are poorly understood. In this study, we focused on the role of NPC-derived exosomes on angiogenesis. Exosomes derived from the NPC C666-1 cells and immortalized nasopharyngeal epithelial cells (NP69 and NP460) were isolated using ultracentrifugation. The molecular profile and biophysical characteristics of exosomes were verified by Western blotting, sucrose density gradient and electron microscopy. We showed that the C666-1 exosomes (10 and 20 μg/ml) could significantly increase the tubulogenesis, migration and invasion of human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. Subsequently, an iTRAQ-based quantitative proteomics was used to identify the differentially expressed proteins in C666-1 exosomes. Among the 640 identified proteins, 51 and 89 proteins were considered as up- and down-regulated (≥ 1.5-fold variations) in C666-1 exosomes compared to the normal counterparts, respectively. As expected, pro-angiogenic proteins including intercellular adhesion molecule-1 (ICAM-1) and CD44 variant isoform 5 (CD44v5) are among the up-regulated proteins, whereas angio-suppressive protein, thrombospondin-1 (TSP-1) was down-regulated in C666-1 exosomes. Further confocal microscopic study and Western blotting clearly demonstrated that the alteration of ICAM-1 and TSP-1 expressions in recipient HUVECs are due to internalization of exosomes. Taken together, these data strongly indicated the critical roles of identified angiogenic proteins in the involvement of exosomes-induced angiogenesis, which could potentially be developed as therapeutic targets in future.
authors: Department of Biology, Faculty of Science, Hong Kong Baptist University, Hong Kong SAR.
authors: Yuk-Kit
authors: YK
authors: Chan
authors: Bioscience Core Laboratory, King Abdullah, University of Science and Technology, Saudi Arabia.
authors: Huoming
authors: H
authors: Zhang
authors: Department of Biology, Faculty of Science, Hong Kong Baptist University, Hong Kong SAR.
authors: Pei
authors: P
authors: Liu
authors: Department of Anatomy, University of Hong Kong.|Center for Nasopharyngeal Carcinoma Research, University of Hong Kong.
authors: Sai-Wah
authors: SW
authors: Tsao
authors: Center for Nasopharyngeal Carcinoma Research, University of Hong Kong.|Department of Clinical Oncology, University of Hong Kong.
authors: Maria Li
authors: ML
authors: Lung
authors: Department of Biology, Faculty of Science, Hong Kong Baptist University, Hong Kong SAR.|Center for Nasopharyngeal Carcinoma Research, University of Hong Kong.
authors: Nai-Ki
authors: NK
authors: Mak
authors: Department of Biology, Faculty of Science, Hong Kong Baptist University, Hong Kong SAR.
authors: Ricky
authors: R
authors: Ngok-Shun Wong
authors: Department of Biology, Faculty of Science, Hong Kong Baptist University, Hong Kong SAR.
authors: Patrick
authors: P
authors: Ying-Kit Yue
mesh_terms: D042501:Angiogenic Proteins / Q000378:metabolism*; D002277:Carcinoma; D045744:Cell Line, Tumor; D002465:Cell Movement; D055354:Exosomes / Q000378:metabolism / Q000473:pathology*; D015972:Gene Expression Regulation, Neoplastic; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*
chemical_list: D042501:Angiogenic Proteins
keywords: angiogenesis; exosomes; iTRAQ; nasopharyngeal carcinoma; proteomic