Exosomes Derived from Squamous Head and Neck Cancer Promote Cell Survival after Ionizing Radiation

• Published in: PloS one Vol. 11; no. 3; p. e0152213
• Main Authors: Mutschelknaus, Lisa, Peters, Carsten, Winkler, Klaudia, Yentrapalli, Ramesh, Heider, Theresa, Atkinson, Michael John, Moertl, Simone
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 23-03-2016; Public Library of Science (PLoS)
• Subjects: Analysis; Biology; Biology and life sciences; Breast cancer; Cancer; Cancer therapies; Carcinoma, Squamous Cell - radiotherapy; Cell culture; Cell growth; Cell Line, Tumor - radiation effects; Cell proliferation; Cell Proliferation - physiology; Cell Proliferation - radiation effects; Cell survival; Cell Survival - radiation effects; Centrifugation; Communication; Conditioning; Deoxyribonucleic acid; Destabilization; Development and progression; DNA; DNA damage; DNA repair; Double-strand break repair; Environmental health; Exosomes; Exosomes - physiology; Exosomes - ultrastructure; Gas vesicles; Genetic aspects; Head; Head & neck cancer; Head and neck cancer; Head and Neck Neoplasms - radiotherapy; Humans; Ionizing radiation; Irradiated; Irradiation; Lung cancer; Medical research; Medicine and Health Sciences; MicroRNAs; Microscopy, Electron; Oxidative stress; Physical Sciences; Physiological aspects; Radiation; Radiation effects; Radioresistance; Research and Analysis Methods; Squamous cell carcinoma; Studies; Survival; Tumor cell lines; Tumor cells; Tumors; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0152213

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.