Up-regulation of Bcl-2 expression in cultured human lymphocytes after exposure to low doses of gamma radiation

Azimian, H. and Bahreyni-Toossi, M. T. and Rezaei, A. R. and Rafatpanah, H. and Hamzehloei, T. and Fardid, R. (2015) Up-regulation of Bcl-2 expression in cultured human lymphocytes after exposure to low doses of gamma radiation. Journal of Medical Physics, 40 (1). pp. 38-44.

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Abstract

Lymphocytes have demonstrated complex molecular responses to induced stress by ionizing radiation. Many of these reactions are mediated through modifications in gene expressions, including the genes involved in apoptosis. The primary aim of this study was to assess the effects of low doses of ionizing radiation on the apoptotic genes, expression levels. The secondary goal was to estimate the time.effect on the modified gene expression caused by low doses of ionizing radiation. Mononuclear cells in culture were exposed to various dose values ranged from 20 to 100 mGy by gamma rays from a Cobalt-60 source. Samples were taken for gene expression analysis at hours 4, 24, 48, 72, and 168 following to exposure. Expression level of two apoptotic genes; BAX (pro-apoptotic) and Bcl-2 (anti-apoptotic) were examined by relative quantitative real-time polymerase chain reaction (PCR), at different time intervals. Radio-sensitivity of peripheral blood mononucleated cells (PBMCs) was measured by the Bcl-2/BAX ratio (as a predictive marker for radio-sensitivity). The non-parametric two independent samples Mann-Whitney U-test were performed to compare means of gene expression. The results of this study revealed that low doses of gamma radiation can induce early down-regulation of the BAX gene of freshly isolated human PBMCs; however, these changes were restored to near normal levels after 168 hours. In most cases, expression of the Bcl-2 anti-apoptotic gene was up-regulated. Four hours following to exposure to low doses of gamma radiation, apoptotic gene expression is modified, this is manifested as adaptive response. Modification of these gene expressions seems to be a principle pathway in the early radioresistance response. In our study, we found that these changes were temporary and faded completely within a week.

Item Type: Article
Additional Information: Cited By :17 Export Date: 16 February 2020 Correspondence Address: Bahreyni-Toossi, M.T.; Medical Physics Research Center, Faculty of Medicine, Mashhad University of Medical SciencesIran; email: BahreyniMT@mums.ac.ir
Uncontrolled Keywords: Apoptosis deoxyribose nucleic acid damage gene expression ionizing radiation cobalt 60 protein Bax protein bcl 2 adult Article BAX gene controlled study dosimetry down regulation gamma radiation gene human human cell lymphocyte male mononuclear cell protein expression proto oncogene quantitative analysis radiation dose distribution radiation exposure radiosensitivity real time polymerase chain reaction upregulation young adult
Subjects: QT physiology
Divisions: Mashhad University of Medical Sciences
Depositing User: mr lib5 lib5
Date Deposited: 12 May 2020 08:08
Last Modified: 12 May 2020 08:08
URI: http://eprints.mums.ac.ir/id/eprint/18768

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