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Modulation of radiation-induced base excision repair pathway gene expression by melatonin
Saeed Rezapoor1, Alireza Shirazi2, Sakineh Abbasi3, Javad Tavakkoly Bazzaz2, Pantea Izadi2, Hamed Rezaeejam4, Majid Valizadeh5, Farid Soleimani-Mohammadi6, Masoud Najafi7
1 Department of Radiology, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran
2 Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
3 Department of Medical Biotechnology, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran
4 Department of Radiology, Allied Medical School, Zanjan University of Medical Sciences, Zanjan, Iran
5 Department of Medical Physics, Faculty of Medicine, Zabol University of Medical Sciences, Zabol, Iran
6 Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
7 Department of Radiology and Nuclear Medicine, School of Paramedical Sciences, Kermanshah University of Medical Sciences, Kermanshah, Iran
Correspondence Address:
Alireza Shirazi
Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran
Iran
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jmp.JMP_9_17
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Objective: Approximately 70% of all cancer patients receive radiotherapy. Although radiotherapy is effective in killing cancer cells, it has adverse effects on normal cells as well. Melatonin (MLT) as a potent antioxidant and anti-inflammatory agent has been proposed to stimulate DNA repair capacity. We investigated the capability of MLT in the modification of radiation-induced DNA damage in rat peripheral blood cells. Materials and Methods: In this experimental study, male rats (n = 162) were divided into 27 groups (n = 6 in each group) including: irradiation only, vehicle only, vehicle with irradiation, 100 mg/kg MLT alone, 100 mg/kg MLT plus irradiation in 3 different time points, and control. Subsequently, they were irradiated with a single whole-body X-ray radiation dose of 2 and 8 Gy at a dose rate of 200 MU/min. Rats were given an intraperitoneal injection of MLT or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were also taken 8, 24, and 48 h postirradiation, in order to measure the 8-oxoguanine glycosylase1 (Ogg1), Apex1, and Xrcc1 expression using quantitative real-time-polymerase chain reaction. Results: Exposing to the ionizing radiation resulted in downregulation of Ogg1, Apex1, and Xrcc1 gene expression. The most obvious suppression was observed in 8 h after exposure. Pretreatments with MLT were able to upregulate these genes when compared to the irradiation-only and vehicle plus irradiation groups (P < 0.05) in all time points. Conclusion: Our results suggested that MLT in mentioned dose may result in modulation of Ogg1, Apex1, and Xrcc1 gene expression in peripheral blood cells to reduce X-ray irradiation-induced DNA damage. Therefore, administration of MLT may increase the normal tissue tolerance to radiation through enhancing the cell DNA repair capacity. We believed that MLT could play a radiation toxicity reduction role in patients who have undergone radiation treatment as a part of cancer radiotherapy. |
