Page 329 - 2014 Printable Abstract Book
P. 329
between controls and irradiated rats are being identified for verification by quantitave real-time PCR.
Conclusions: Next-generation sequencing provides us with more complete data of microRNA for
biomarker selection, as well as has the potential to advance the field by identifying new and unknown
microRNA induced by irradiation. Grant: NIH/NIAID 1R01AI101898-01 & 1U01AI107305-01.
(PS6-08) Alpha-particle-induced DNA double strand breaks and repair in human blood lymphocytes.
Honghong Chen; Yaping Zhang; Xuxia Zhang; Jing Wang; Yizhong Bao; and Lina Yin, Institute of Radiation
Medicine, Fudan University, Shanghai, China
Purpose: Internal exposure to ionizing radiation play an important role in radiation-induced
human health hazards especially from α-particle emitters, such as radon and its progeny, plutonium,
americium, radium and so on. Our aim was to investigate the characteristics of repair of DNA double
strand breaks (DSBs) induced by high-LET α-particles in the lymphocytes of human peripheral blood and
explore the biological indicator as the judgement and dose estimation of internal exposure to α-particles.
Methods: Samples of peripheral whole blood were collected from four healthy adults and lymphocytes
were separated. Monocellular layer of lymphocytes attached in Mylar membrane was irradiated with 0
and 0.5 Gy of 241 Am α radioactive source and γ-rays, respectively. The formation of γH2AX foci as a
surrogate marker of DSBs, phospho-DNA-PKcs foci as an indicator of nonhomologous end joining (NHEJ)
repair and Rad51 foci as an indicator of homologous recombination (HR) repair were measured by
immunofluorescence staining technique. Results: The formation of linear γH2AX foci tracks reached the
peak at 10 min and almost completely disappeared at 6 h after exposure to α-particles. Similarly, the
formation of phospho-DNA-PKcs foci tracks were observed along with parts of the tracks of γH2AX foci at
10 - 30 min post-irradiation. The average number of residual γH2AX foci remained at approximately 16%
at 24 - 48 h after α-particles irradiation. In contrast, no linear γH2AX foci tracks were observed and γH2AX
foci diffused randomly in nucleus at 10 min - 48 h after γ-ray irradiation. The numbers of formative and
residual γH2AX foci after γ-rays irradiation were significantly less than those induced by α-particles. During
30 min - 2 h after exposure to α-particle, the frequencies of Rad51 foci slightly but not significantly
increased as compared to background level. Conclusions: The formation of linear γH2AX foci tracks
induced by α-particles in lymphocytes could be used as biological indicator to estimate whether a person
has been exposed to α-particle internal irradiation. NHEJ plays a key role in the repair of DSBs induced by
α-particles and γ-rays irradiation in lymphocytes. Acknowledgements: This study was supported by grant
81273000 from the National Nature Science Foundation of China.
(PS6-09) Predictive biomarkers for radiation-lung injury: repurposing novel imaging probes. Meetha
1
1
1
1;2
1
3
Medhora ; Steven Haworth ; Yu Liu ; Jayashree Narayanan ; Ming Zhao ; John Moulder ; Elizabeth
Jacobs ; Brian Fish ; and Anne Clough 1;2;4 , Medical College of Wisconsin, Milwaukee, WI ; Dept of
1
1;2
1
2
Veterans Affairs, Zablocki Veterans Affairs Med Ctr, Milwaukee, WI ; Feinberg School of Med,
3
Northwestern University, Chicago, IL ; and Marquette University, Milwaukee, WI
4
Introduction: Radiation to the lung can induce lethal pneumonitis after a latent period of 6 weeks
or more. We have found that angiotensin converting enzyme (ACE) inhibitors that improve survival from
thoracic irradiation even if started after 5 weeks. Goal: To identify noninvasive imaging methods that will
predict lethal lung injury before 5 weeks following irradiation to enable mitigation. Methods: Rats (female
327 | P a g e
Conclusions: Next-generation sequencing provides us with more complete data of microRNA for
biomarker selection, as well as has the potential to advance the field by identifying new and unknown
microRNA induced by irradiation. Grant: NIH/NIAID 1R01AI101898-01 & 1U01AI107305-01.
(PS6-08) Alpha-particle-induced DNA double strand breaks and repair in human blood lymphocytes.
Honghong Chen; Yaping Zhang; Xuxia Zhang; Jing Wang; Yizhong Bao; and Lina Yin, Institute of Radiation
Medicine, Fudan University, Shanghai, China
Purpose: Internal exposure to ionizing radiation play an important role in radiation-induced
human health hazards especially from α-particle emitters, such as radon and its progeny, plutonium,
americium, radium and so on. Our aim was to investigate the characteristics of repair of DNA double
strand breaks (DSBs) induced by high-LET α-particles in the lymphocytes of human peripheral blood and
explore the biological indicator as the judgement and dose estimation of internal exposure to α-particles.
Methods: Samples of peripheral whole blood were collected from four healthy adults and lymphocytes
were separated. Monocellular layer of lymphocytes attached in Mylar membrane was irradiated with 0
and 0.5 Gy of 241 Am α radioactive source and γ-rays, respectively. The formation of γH2AX foci as a
surrogate marker of DSBs, phospho-DNA-PKcs foci as an indicator of nonhomologous end joining (NHEJ)
repair and Rad51 foci as an indicator of homologous recombination (HR) repair were measured by
immunofluorescence staining technique. Results: The formation of linear γH2AX foci tracks reached the
peak at 10 min and almost completely disappeared at 6 h after exposure to α-particles. Similarly, the
formation of phospho-DNA-PKcs foci tracks were observed along with parts of the tracks of γH2AX foci at
10 - 30 min post-irradiation. The average number of residual γH2AX foci remained at approximately 16%
at 24 - 48 h after α-particles irradiation. In contrast, no linear γH2AX foci tracks were observed and γH2AX
foci diffused randomly in nucleus at 10 min - 48 h after γ-ray irradiation. The numbers of formative and
residual γH2AX foci after γ-rays irradiation were significantly less than those induced by α-particles. During
30 min - 2 h after exposure to α-particle, the frequencies of Rad51 foci slightly but not significantly
increased as compared to background level. Conclusions: The formation of linear γH2AX foci tracks
induced by α-particles in lymphocytes could be used as biological indicator to estimate whether a person
has been exposed to α-particle internal irradiation. NHEJ plays a key role in the repair of DSBs induced by
α-particles and γ-rays irradiation in lymphocytes. Acknowledgements: This study was supported by grant
81273000 from the National Nature Science Foundation of China.
(PS6-09) Predictive biomarkers for radiation-lung injury: repurposing novel imaging probes. Meetha
1
1
1
1;2
1
3
Medhora ; Steven Haworth ; Yu Liu ; Jayashree Narayanan ; Ming Zhao ; John Moulder ; Elizabeth
Jacobs ; Brian Fish ; and Anne Clough 1;2;4 , Medical College of Wisconsin, Milwaukee, WI ; Dept of
1
1;2
1
2
Veterans Affairs, Zablocki Veterans Affairs Med Ctr, Milwaukee, WI ; Feinberg School of Med,
3
Northwestern University, Chicago, IL ; and Marquette University, Milwaukee, WI
4
Introduction: Radiation to the lung can induce lethal pneumonitis after a latent period of 6 weeks
or more. We have found that angiotensin converting enzyme (ACE) inhibitors that improve survival from
thoracic irradiation even if started after 5 weeks. Goal: To identify noninvasive imaging methods that will
predict lethal lung injury before 5 weeks following irradiation to enable mitigation. Methods: Rats (female
327 | P a g e
