Radiation alters the cargo of exosomes released from squamous head and neck cancer cells to promote migration of recipient cells

Sci Rep. 2017 Sep 29;7(1):12423. doi: 10.1038/s41598-017-12403-6.

Abstract

Radiation is a highly efficient therapy in squamous head and neck carcinoma (HNSCC) treatment. However, local recurrence and metastasis are common complications. Recent evidence shows that cancer-cell-derived exosomes modify tumour cell movement and metastasis. In this study, we link radiation-induced changes of exosomes to their ability to promote migration of recipient HNSCC cells. We demonstrate that exosomes isolated from irradiated donor cells boost the motility of the HNSCC cells BHY and FaDu. Molecular data identified enhanced AKT-signalling, manifested through increased phospho-mTOR, phospho-rpS6 and MMP2/9 protease activity, as underlying mechanism. AKT-inhibition blocked the pro-migratory action, suggesting AKT-signalling as key player in exosome-mediated migration. Proteomic analysis of exosomes isolated from irradiated and non-irradiated BHY donor cells identified 39 up- and 36 downregulated proteins. In line with the observed pro-migratory effect of exosomes isolated from irradiated cells protein function analysis assigned the deregulated exosomal proteins to cell motility and AKT-signalling. Together, our findings demonstrate that exosomes derived from irradiated HNSCC cells confer a migratory phenotype to recipient cancer cells. This is possibly due to radiation-regulated exosomal proteins that increase AKT-signalling. We conclude that exosomes may act as driver of HNSCC progression during radiotherapy and are therefore attractive targets to improve radiation therapy strategies.

MeSH terms

  • Cell Line, Tumor
  • Cell Movement / radiation effects*
  • Exosomes* / metabolism
  • Exosomes* / radiation effects
  • Head and Neck Neoplasms* / pathology
  • Head and Neck Neoplasms* / radiotherapy
  • Humans
  • Matrix Metalloproteinase 2 / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • Neoplasm Metastasis
  • Neoplasm Recurrence, Local / pathology
  • Proteomics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Ribosomal Protein S6 / metabolism
  • Signal Transduction
  • Squamous Cell Carcinoma of Head and Neck* / pathology
  • Squamous Cell Carcinoma of Head and Neck* / radiotherapy
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Ribosomal Protein S6
  • MTOR protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • MMP2 protein, human
  • Matrix Metalloproteinase 2
  • MMP9 protein, human
  • Matrix Metalloproteinase 9