Human papillomavirus status and the relative biological effectiveness of proton radiotherapy in head and neck cancer cells

Li Wang, Xiaochun Wang, Yuting Li, Shichao Han, Jinming Zhu, Xiaofang Wang, David P. Molkentine, Pierre Blanchard, Yining Yang, Ruiping Zhang, Narayan Sahoo, Michael Gillin, Xiaorong Ronald Zhu, Xiaodong Zhang, Jeffrey N. Myers, Steven J. Frank

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)

Abstract

Background: Human papillomavirus (HPV)-positive oropharyngeal carcinomas response better to X-ray therapy (XRT) than HPV-negative disease. Whether HPV status influences the sensitivity of head and neck cancer cells to proton therapy or the relative biological effectiveness (RBE) of protons versus XRT is unknown. Methods: Clonogenic survival was used to calculate the RBE; immunocytochemical analysis and neutral comet assay were used to evaluate unrepaired DNA double-strand breaks. Results: HPV-positive cells were more sensitive to protons and the unrepaired double-strand breaks were more numerous in HPV-positive cells than in HPV-negative cells (p <.001). Protons killed more cells than did XRT at all fraction sizes (all RBEs > 1.06). Cell line type and radiation fraction size influenced the RBE. Conclusion: HPV-positive cells were more sensitive to protons than HPV-negative cells maybe through the effects of HPV on DNA damage and repair. The RBE for protons depends more on cell type and fraction size than on HPV status.

Original languageEnglish
Pages (from-to)708-715
Number of pages8
JournalHead and Neck
Volume39
Issue number4
DOIs
Publication statusPublished - 1 Apr 2017
Externally publishedYes

Keywords

  • head and neck cancer
  • human papillomavirus
  • proton radiotherapy
  • radiosensitivity
  • relative biological effectiveness

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