Dose-effect relationships of ¹²C⁶⁺ ions-induced dicentric plus ring chromosomes, micronucleus and nucleoplasmic bridges in human lymphocytes in vitro

Abstract

Purpose

The objective of this research was to explore the dose-effect relationships of dicentric plus ring (dic + r), micronucleus (MN) and nucleoplasmic bridges (NPB) induced by carbon ions in human lymphocytes.

Materials and methods

Venous blood samples were collected from three healthy donors. ¹²C⁶⁺ ions beam was used to irradiate the blood samples at the energy of 330 MeV and linear energy transfer (LET) of 50 keV/μm with a dose rate of 1 Gy/min in the spread-out Bragg peak. The irradiated doses were 0 (sham irradiation), 1, 2, 3, 4, 5 and 6 Gy. Dic + r chromosomes aberrations were scored in metaphases. The cytokinesis-block micronucleus cytome (CBMN) was conducted to analyze MN and NPB. The maximum low-dose relative biological effectiveness (RBE_M) values of the induction of dic + r, MN and NPB in human lymphocytes for ¹²C⁶⁺ ions irradiation was calculated relative to ⁶⁰Co γ-rays.

Results

The frequencies of dic + r, MN and NPB showed significantly increases in a dose-depended manner after exposure to ¹²C⁶⁺ ions. The distributions of dic + r and MN exhibited overdispersion, while the distribution of NPB agreed with Poisson distribution at all doses. Linear-quadratic equations were established based on the frequencies of dic + r and MN. The dose-response curves of NPB frequencies followed a linear model. The derived RBE_M values for dic + r, MN and NPB in human lymphocytes irradiated with ¹²C⁶⁺ ions were 8.07 ± 2.73, 2.69 ± 0.20 and 4.00 ± 2.69 in comparison with ⁶⁰Co γ-rays.

Conclusion

The dose-response curves of carbon ions-induced dic + r, MN and NPB were constructed. These results could be helpful to improve radiation risk assessment and dose estimation after exposed to carbon ions irradiation.

Keywords:

• 12C6+ heavy ion
• dicentrics
• micronucleus
• nucleoplasmic bridges

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the grants from National Natural Science Foundation of China [grant nos. 81573081 and 81803162].

Notes on contributors

Tian-Jing Cai

Tian-Jing Cai, MPH. She is a Research Associate in the Department of Radiobiology, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Shuang Li

Shuang Li, MD. She is an Associate Researcher in the Department of Radiobiology, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Xue Lu

Xue Lu, BA. She is an Associate Senior Technician in the Department of Radiobiology, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Chun-Fei Zhang

Chun-Fei Zhang, BA. He is a physician in Central Medical District of PLA General Hospital

Ji-Long Yuan

Ji-Long Yuan, PhD. He is an Associate Researcher in the Department of Safety and Protection of Radiotherapy, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Qing-Zhao Zhang

Qing-Zhao Zhang, MMS. He is a Research Associate in the Department of Radiation Protection, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Xue-Lei Tian

Xue-Lei Tian, MMS. She is a Research Associate in the Department of Radiobiology, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

De-Xing Lian

De-Xing Lian, MMS. He is a Research Associate in the Department of Radiation Protection, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Ming-Sheng Li

Ming-Sheng Li, MMS. He is an Associate Researcher in the Department of Safety and Protection of Radiotherapy, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Zhen Zhang

Zhen Zhang, PhD. He is a Researcher in the Department of Radiation Protection, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Gang Liu

Gang Liu, BA. He is a Senior Technician in Gansu Province Center for Disease Control and Prevention.

Hua Zhao

Hua Zhao, PhD. He is a Research Associate in the Department of Radiobiology, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Li-Mei Niu

Li-Mei Niu, BA. She is a Technologist-in-Charge in Gansu Province Center for Disease Control and Prevention.

Mei Tian

Mei Tian, PhD. She is theHead of the Department of Radiobiology, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Chang-Song Hou

Chang-Song Hou, PhD. He is the Head of the Department of Radiation Protection, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention.

Qing-Jie Liu

Qing-Jie Liu, MD/PhD. He is a professor of Radiobiology, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention. His research field is biological effects of ionizing radiation.