title: Active macropinocytosis induction by stimulation of epidermal growth factor receptor and oncogenic Ras expression potentiates cellular uptake efficacy of exosomes.
abstract: Exosomes are approximately 100-nm vesicles that consist of a lipid bilayer of cellular membranes secreted in large quantities from various types of normal and disease-related cells. Endocytosis has been reported as a major pathway for the cellular uptake of exosomes; however, the detailed mechanisms of their cellular uptake are still unknown. Here, we demonstrate the active induction of macropinocytosis (accompanied by actin reorganisation, ruffling of plasma membrane, and engulfment of large volumes of extracellular fluid) by stimulation of cancer-related receptors and show that the epidermal growth factor (EGF) receptor significantly enhances the cellular uptake of exosomes. We also demonstrate that oncogenic K-Ras-expressing MIA PaCa-2 cells exhibit intensive macropinocytosis that actively transports extracellular exosomes into the cells compared with wild-type K-Ras-expressing BxPC-3 cells. Furthermore, encapsulation of the ribosome-inactivating protein saporin with EGF in exosomes using our simple electroporation method produces superior cytotoxicity via the enhanced cellular uptake of exosomes. Our findings contribute to the biological, pharmaceutical, and medical research fields in terms of understanding the macropinocytosis-mediated cellular uptake of exosomes with applications for exosomal delivery systems.
authors.affiliation: Nanoscience and Nanotechnology Research Center, Research Organization for the 21st Century, Osaka Prefecture University, Naka-ku, Sakai, Osaka 599-8570, Japan.
authors.forename: Ikuhiko
authors.initials: I
authors.lastname: Nakase
authors.affiliation: 1] Keio Advanced Research Centers (KARC), Keio University, Tsukuba, Ibaraki 300-2611, Japan [2] Institute for Advanced Sciences, Toagosei Co., Ltd., Tsukuba, Ibaraki 300-2611, Japan.
authors.forename: Nahoko Bailey
authors.initials: NB
authors.lastname: Kobayashi
authors.affiliation: Department of Pharmaceutics, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, 11-68, Koshien Kyuban-cho, Nishinomiya, Hyogo 663-8179, Japan.
authors.forename: Tomoka
authors.initials: T
authors.lastname: Takatani-Nakase
authors.affiliation: 1] Keio Advanced Research Centers (KARC), Keio University, Tsukuba, Ibaraki 300-2611, Japan [2] Institute for Advanced Sciences, Toagosei Co., Ltd., Tsukuba, Ibaraki 300-2611, Japan.
authors.forename: Tetsuhiko
authors.initials: T
authors.lastname: Yoshida
mesh_terms: D001692:Biological Transport; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism*; D055354:Exosomes / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D010873:Pinocytosis / Q000187:drug effects; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics* / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000378:metabolism; D054789:Ribosome Inactivating Proteins, Type 1 / Q000378:metabolism; D000076985:Saporins; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D019718:Receptors, CXCR4; D054789:Ribosome Inactivating Proteins, Type 1; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D000076985:Saporins; D016283:Proto-Oncogene Proteins p21(ras)