title: Exosomes Derived from Squamous Head and Neck Cancer Promote Cell Survival after Ionizing Radiation.
abstract: Exosomes are nanometer-sized extracellular vesicles that are believed to function as intercellular communicators. Here, we report that exosomes are able to modify the radiation response of the head and neck cancer cell lines BHY and FaDu. Exosomes were isolated from the conditioned medium of irradiated as well as non-irradiated head and neck cancer cells by serial centrifugation. Quantification using NanoSight technology indicated an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response of other cells the exosomes were transferred to non-irradiated and irradiated recipient cells. We found an enhanced uptake of exosomes isolated from both irradiated and non-irradiated cells by irradiated recipient cells compared to non-irradiated recipient cells. Functional analyses by exosome transfer indicated that all exosomes (from non-irradiated and irradiated donor cells) increase the proliferation of non-irradiated recipient cells and the survival of irradiated recipient cells. The survival-promoting effects are more pronounced when exosomes isolated from irradiated compared to non-irradiated donor cells are transferred. A possible mechanism for the increased survival after irradiation could be the increase in DNA double-strand break repair monitored at 6, 8 and 10 h after the transfer of exosomes isolated from irradiated cells. This is abrogated by the destabilization of the exosomes. Our results demonstrate that radiation influences both the abundance and action of exosomes on recipient cells. Exosomes transmit prosurvival effects by promoting the proliferation and radioresistance of head and neck cancer cells. Taken together, this study indicates a functional role of exosomes in the response of tumor cells to radiation exposure within a therapeutic dose range and encourages that exosomes are useful objects of study for a better understanding of tumor radiation response.
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Biology, Neuherberg, Germany.
authors.forename: Lisa
authors.initials: L
authors.lastname: Mutschelknaus
authors.affiliation: Department of Chemistry, Technical University of Munich, Munich, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Peters
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Biology, Neuherberg, Germany.
authors.forename: Klaudia
authors.initials: K
authors.lastname: Winkler
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Biology, Neuherberg, Germany.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Yentrapalli
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Biology, Neuherberg, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Heider
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Biology, Neuherberg, Germany.|Radiation Biology, Technical University of Munich, Munich, Germany.
authors.forename: Michael John
authors.initials: MJ
authors.lastname: Atkinson
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Biology, Neuherberg, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Moertl
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D045744:Cell Line, Tumor / Q000528:radiation effects; D049109:Cell Proliferation / Q000502:physiology / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects*; D055354:Exosomes / Q000502:physiology* / Q000648:ultrastructure; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008854:Microscopy, Electron