Abstract
Background: Photon (X-ray) radiotherapy (XRT) kills cells via DNA damage, however, how proton radiotherapy (PRT) causes cell death in head and neck squamous cell carcinoma (HNSCC) is unclear. We investigated mechanisms of HNSCC cell death after XRT versus PRT. Methods: We assessed type of death in 2 human papillomavirus (HPV)-positive and two HPV-negative cell lines: necrosis and apoptosis (Annexin-V fluorescein isothiocyanate [FITC]); senescence (β-galactosidase); and mitotic catastrophe (γ-tubulin and diamidino-phenylindole [DAPI]). Results: The XRT-induced or PRT-induced cellular senescence and mitotic catastrophe in all cell lines studied suggested that PRT caused cell death to a greater extent than XRT. After PRT, mitotic catastrophe peaked in HPV-negative and HPV-positive cells at 48 and 72 hours, respectively. No obvious differences were noted in the extent of cell necrosis or apoptosis after XRT versus PRT. Conclusion: Under the conditions and in the cell lines reported here, mitotic catastrophe and senescence were the major types of cell death induced by XRT and PRT, and PRT may be more effective.
Original language | English (US) |
---|---|
Pages (from-to) | 46-55 |
Number of pages | 10 |
Journal | Head and Neck |
Volume | 41 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2019 |
Keywords
- cell death mechanisms
- head and neck cancer
- photon radiotherapy
- proton radiotherapy
- radiation-induced cell death
ASJC Scopus subject areas
- Otorhinolaryngology
MD Anderson CCSG core facilities
- Advanced Technology Genomics Core
- Flow Cytometry and Cellular Imaging Facility
- Cytogenetics and Cell Authentication Core