Abstract
Purpose: Our aim was to evaluate whether mitochondrial DNA (mtDNA) damage in hair bulbs could be a suitable biomarker for the detection of local exposure to ionizing radiation.
Materials and methods: Mouse hair was collected 4 and 24 hours, 3 and 10 days after single whole-body exposure to 0, 0.1, and 2 Gy radiation. Pubic hair (treated area) and scalp hair (control area) were collected from 13 prostate cancer patients before and after fractioned radiotherapy with an average total dose of 2.7 Gy to follicles after five fractions. Unspecified lesion frequency of mtDNA was analyzed with long PCR, large mtDNA deletion levels were tested with real-time PCR.
Results: Unspecified lesion frequency of mtDNA significantly increased in mouse hair 24 hours after irradiation with 2 Gy, but variance among samples was high. No increase in lesion frequency could be detected after 0.1 Gy irradiation. In prostate cancer patients, there was no significant change in either the unspecified lesion frequency or in the proportion of 4934-bp deleted mtDNA in pubic hair after radiotherapy. The proportions of murine 3860-bp common deletion, human 4977-bp common deletion and 7455-bp deleted mtDNA were too low to be analyzed reliably.
Conclusions: Our results suggest that the unspecified lesion frequency and proportion of large deletions of mtDNA in hair bulbs are not suitable biomarkers of exposure to ionizing radiation.
Acknowledgements
The authors are grateful to N. Sándor and L. Szőllősi for help in the experimental procedure with mice. The authors thank A. Juutilainen, A. Palomaa, K. Tervo, and P. Vesterinen for collecting the human hair samples.
Disclosure statement
No potential conflict of interest was reported by the authors.
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Notes on contributors
Rita Hargitai
Rita Hargitai, PhD, is a senior researcher at the Department of Radiation Medicine of the Division of Radiobiology and Radiohygiene of the National Public Health Center in Budapest, Hungary
Päivi Roivainen
Päivi Roivainen, PhD, is a senior researcher at the Department of Environmental and Biological Sciences of the University of Eastern Finland in Kuopio, Finland.
Dávid Kis
Dávid Kis is a PhD student at Semmelweis University and a researcher at the Department of Radiation Medicine of the Division of Radiobiology and Radiohygiene of the National Public Health Center in Budapest, Hungary
Jukka Luukkonen
Jukka Luukkonen, PhD, is a senior lecturer at the Department of Environmental and Biological Sciences of the University of Eastern Finland in Kuopio, Finland.
Géza Sáfrány
Géza Sáfrány, MD, PhD, DSc, is the head of the Division of Radiobiology and Radiohygiene of the National Public Health Center in Budapest, Hungary.
Jan Seppälä
Jan Seppälä, PhD, is adjunct professor and chief physicist at the Center of Oncology of the Kuopio University Hospital in Kuopio, Finland
Tünde Szatmári
Tünde Szatmári, PhD, is a senior researcher at the Department of Radiation Medicine of the Division of Radiobiology and Radiohygiene of the National Public Health Center in Budapest, Hungary
Tuomas Virén
Tuomas Virén, PhD, is adjunct professor and a medical physicist at the Center of Oncology of the Kuopio University Hospital in Kuopio, Finland
Kristiina Vuolukka
Kristiina Vuolukka, MD, is a medical oncologist at the Center of Oncology of the Kuopio University Hospital in Kuopio, Finland
Sisko Salomaa
Sisko Salomaa, PhD, is professor of radiobiology at the Department of Environmental and Biological Sciences of the University of Eastern Finland in Kuopio, Finland, leading the OPERRA project task on biomarkers and biobanking.
Katalin Lumniczky
Katalin Lumniczky, MD, PhD, is the head of the Department of Radiation Medicine of the Division of Radiobiology and Radiohygiene of the National Public Health Center in Budapest, Hungary