RRC ID 63532
Author Tomita M, Maeda M, Usami N, Yokoya A, Watanabe R, Kobayashi K.
Title Enhancement of DNA double-strand break induction and cell killing by K-shell absorption of phosphorus in human cell lines.
Journal Int J Radiat Biol
Abstract PURPOSE:To investigate an enhancement of DNA double-strand break (DSB) induction and cell killing effect by K-shell ionization of phosphorus atoms and Auger electrons on human cell lines.
MATERIALS AND METHODS:Induction of DSB, DNA damage responses, cell cycle distributions, and cell killing effects were investigated after exposures of the cells with monochromatic synchrotron radiation soft X-rays of 2153 and 2147 eV, which were the resonance peak and off peak, respectively, of the K-shell photoabsorption of phosphorus.
RESULTS:Higher biological effects in the cells irradiated with soft X-rays at 2153 eV than at 2147 eV were observed in (i) the efficiency of 53BP1/γ-H2AX co-localized foci formation per dose and residual number of foci, (ii) prolonged phosphorylation levels of DSB repair and/or cell cycle checkpoint related proteins and G2 arrest, (iii) the cell killing effects at the 10% survival level of normal human fibroblasts, HeLa cells, and human glioblastoma M059K cells (1.2-1.5 times higher) and that of human ataxia telangiectasia mutated (ATM)-defective cells and glioblastoma DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-defective cells (1.2 times).
CONCLUSION:The yield of DSB and partly less-reparable complex DNA damage induction in human cells was enhanced by K-shell photoabsorption of phosphorus and low-energy Auger electrons.
Volume 92(11)
Pages 724-732
Published 2016-11-1
DOI 10.1080/09553002.2016.1179811
PMID 27185241
MeSH Absorption, Radiation Apoptosis / drug effects* Apoptosis / genetics* Cell Line, Tumor DNA Damage / genetics* Dose-Response Relationship, Radiation Electrons / therapeutic use Humans Neoplasms, Experimental / genetics* Neoplasms, Experimental / pathology Neoplasms, Experimental / radiotherapy* Phosphorus / radiation effects* Radiotherapy Dosage Treatment Outcome
IF 2.368
Human and Animal Cells HeLa