RRC ID 65684
Author Sunada S, Hirakawa H, Fujimori A, Uesaka M, Okayasu R.
Title Oxygen Enhancement Ratio in Radiation-Induced Initial DSBs by an Optimized Flow Cytometry-based Gamma-H2AX Analysis in A549 Human Cancer Cells.
Journal Radiat Res
Abstract High-linear energy transfer (LET) heavy ions cause higher therapeutic effects than low-LET radiation due to lower dependency on oxygen concentration in tumor cell killing. The lethality after irradiation largely depends on DNA double-strand breaks (DSBs), however the detailed LET dependency for DSB induction under oxic and hypoxic conditions has not been reported. Therefore, we evaluated the oxygen enhancement ratio (OER) of heavy ion-induced DSB induction using a highly-optimized flow cytometry-based method of γ-H2AX detection. Non-small cell lung cancer (NSCLC) A549 cells were exposed to X-ray, carbon-ion and iron-ion radiations under oxic or hypoxic condition. As a DSB marker, the γ-H2AX signal was measured 1 h postirradiation and analyzed by flow cytometry. DSB slope values were calculated as DSB induction per Gy. Our method was able to detect high-LET radiation-induced DSBs even from clustered DNA damage sites. We also showed a decrease in OER value in an LET-dependent manner regardless of radiation type. In summary, we demonstrated a simple, quick and highly-optimized flow cytometry-based method of DSB analysis that detects DSBs induced by heavy-ion radiation for hypoxic and nonhypoxic cancer cells. Our study may provide a useful biological basis for heavy-ion radiotherapy.
Volume 188(5)
Pages 591-594
Published 2017-11-1
DOI 10.1667/RR14824.1
PMID 28829673
MeSH DNA Breaks, Double-Stranded / radiation effects* Dose-Response Relationship, Radiation Flow Cytometry Histones / metabolism* Humans Linear Energy Transfer / radiation effects Oxygen / metabolism*
IF 2.657
Human and Animal Cells A549(RCB0098)