Hongying Yang1, Nicole Magpayo, Kathryn D Held. 1. Department of Radiation Oncology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA. hyang5@partners.org
Abstract
PURPOSE: In space, astronauts are exposed to mixed radiation fields consisting of energetic protons and high atomic number, high energy (HZE) particles at low dose rates. Therefore, it is critical to understand effects of combinations of low doses of different radiation types at the cellular level. MATERIALS AND METHODS: AG01522 normal human skin fibroblasts and a transwell insert co-culture system were used. Irradiations used were 1 GeV/amu (gigaelectron volt/atomic mass unit) protons and 1 GeV/amu iron (Fe) ions. DNA damage was measured as micronucleus (MN) formation and p53 binding protein 1 (53BP1) foci induction. RESULTS: The same magnitude of DNA damage was induced in cells sequentially exposed to 1 cGy protons and 1 cGy Fe ions as in cells irradiated with either protons or Fe ions alone. The same magnitude of DNA damage was also observed in non-irradiated bystander cells sharing medium with cells irradiated with either 1 cGy protons or iron ions or protons plus iron ions. However, when the 'bystander' cells were exposed to 1 cGy protons up to 3 h before co-culture with Fe ion-irradiated cells, no DNA damage in the 'bystander' cells was observed. CONCLUSIONS: These data provide the first evidence of interactions between targeted and non-targeted DNA damage caused by dual exposure to low doses of energetic protons and iron ions.
PURPOSE: In space, astronauts are exposed to mixed radiation fields consisting of energetic protons and high atomic number, high energy (HZE) particles at low dose rates. Therefore, it is critical to understand effects of combinations of low doses of different radiation types at the cellular level. MATERIALS AND METHODS: AG01522 normal human skin fibroblasts and a transwell insert co-culture system were used. Irradiations used were 1 GeV/amu (gigaelectron volt/atomic mass unit) protons and 1 GeV/amu iron (Fe) ions. DNA damage was measured as micronucleus (MN) formation and p53 binding protein 1 (53BP1) foci induction. RESULTS: The same magnitude of DNA damage was induced in cells sequentially exposed to 1 cGy protons and 1 cGy Fe ions as in cells irradiated with either protons or Fe ions alone. The same magnitude of DNA damage was also observed in non-irradiated bystander cells sharing medium with cells irradiated with either 1 cGy protons or iron ions or protons plus iron ions. However, when the 'bystander' cells were exposed to 1 cGy protons up to 3 h before co-culture with Fe ion-irradiated cells, no DNA damage in the 'bystander' cells was observed. CONCLUSIONS: These data provide the first evidence of interactions between targeted and non-targeted DNA damage caused by dual exposure to low doses of energetic protons and iron ions.
Authors: Deepa M Sridharan; Aroumougame Asaithamby; Steve R Blattnig; Sylvain V Costes; Paul W Doetsch; William S Dynan; Philip Hahnfeldt; Lynn Hlatky; Yared Kidane; Amy Kronenberg; Mamta D Naidu; Leif E Peterson; Ianik Plante; Artem L Ponomarev; Janapriya Saha; Antoine M Snijders; Kalayarasan Srinivasan; Jonathan Tang; Erica Werner; Janice M Pluth Journal: Life Sci Space Res (Amst) Date: 2016-05-21
Authors: Carmel Mothersill; Richard W Smith; Lene Sørlie Heier; Hans-Christian Teien; Ole Christian Lind; Ole Christian Land; Colin B Seymour; Deborah Oughton; Brit Salbu Journal: Radiat Environ Biophys Date: 2013-12-19 Impact factor: 1.925
Authors: Bertrand P Tseng; Mary L Lan; Katherine K Tran; Munjal M Acharya; Erich Giedzinski; Charles L Limoli Journal: Redox Biol Date: 2013-01-19 Impact factor: 11.799