UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2022-07-01 16:29

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Conference: Bucharest University Faculty of Physics 2019 Meeting


Section: Biophysics; Medical Physics


Title:
Evaluation of DNA-damage in X-ray exposed human lymphocyte in relationship with sample processing methods


Authors:
Mihaela TEMELIE (1), Mihaela TUDOR (1), Constantin CENUSA (2), Diana SAVU (1)


Affiliation:
1) Department of Life and Environmental Physics, National Institute of Physics and Nuclear Engineering "Horia Hulubei"

2) Radioisotopes and Radiation Metrology Department, National Institute of Physics and Nuclear Engineering "Horia Hulubei"


E-mail
mihaela.temelie@nipne.ro


Keywords:
Lymphocytes, DNA Damage, X-ray, micronuclei, gamma-H2AX


Abstract:
Human lymphocytes representthe most widely used for primary culture, being a less invasive procedure comparing to other primary cultures. Many studies dedicated to radiobiology (biodosimetry, exposure markers, radiosensibility) use as a model human lymphocyte collected by venous puncture. Studies can use various protocols of lymphocyte separation, purification and culture, depending on the parameters and methods of analyses, time required to transport the blood sample, availability of the methods involved etc. The goal of our study was to evaluate the variability of DNA-damage induction on human lymphocyte in relationship to sample processing and store protocols. We collected venous blood from 4 healthy individuals to EDTA vacationer and we separated lymphocyte using a classic protocol involving Bicol gradient. Lymphocytes were isolated in the day of blood collection or second day, keeping the blood at 4 C. Lymphocytes were exposed to 0,5-2 Gy X-ray in the day of collection/isolation or 24 h later. We analyzed DNA damage induced by micronucleus assay and gamma-H2AX immunofluorescence technique. Our study revealed induction of a very high number of DNA double stand breaks in all samples at 3 hours after irradiation, followed by a repair, leading to only a very small gamma-H2AX foci number in the case of 2 Gy exposed samples, 24 hour later. Micronuclei frequency also indicates induction of DNA-damage dependent of the dose. The differences in DNA-damage induction in relationship with sample processing were not significant. Even if we used a small lot of donors composed by matched age/sex healthy donors, we found large inter-individual variability in response to radiation.


Acknowledgement:
PN-III-P1-1.2-PCCDI-64 PCCDI/2018 - component project P4: “Development of a biomarkers set to predict normal tissue toxic adverse reaction in cancer patients radiotherapy to personalize the treatment”