Bahreyni-Toossi Mohammad Taghi, Vosoughi Habibeh, Azimian Hosein, Rezaei Abdul Rahim, Momennezhad Mehdi
Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Immunology Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Asia Ocean J Nucl Med Biol. 2018 Winter;6(1):32-40. doi: 10.22038/aojnmb.2017.9678.
In recent years, the application of radiopharmaceuticals in nuclear medicine has increased substantially. Following the diagnostic procedures performed in nuclear medicine departments, such as myocardial perfusion imaging, patients generally receive considerable doses of radiation. Normally, radiation-induced DNA damages are expected following exposure to a low-dose ionizing radiation. In order to detect molecular changes, high-sensitivity techniques must be utilized. The aim of this study was to assess the effect of a low-dose (below 10 mSv) gamma ray on gene expression using quantitative real-time polymerase chain reaction (qRT-PCR).
Blood samples were obtained from 20 volunteer patients who underwent myocardial perfusion imaging. They were given various doses of Technetium-99m methoxyisobutylisonitrile (Tc-MIBI). After that, peripheral blood mononuclear cells (PBMNs) were derived, and then total RNA was extracted and reverse-transcribed to cDNA. Finally, the expression levels of xeroderma pigmentosum complementation group-A and ferredoxin reductase genes were determinded through qRT-PCR technique using SYBR Green.
and expression levels were obtained following a very low-dose ionizing radiation. A significant up-regulation of both genes was observed, and the gene expression level of each individual patient was different. If differences in the administered activity and radiosensitivity are taken into account, the observed differences could be justified. Furthermore, gender and age did not play a significant role in the expression levels of the genes under study.
The up-regulation of after irradiation revealed the high-sensitivity level of this gene; therefore, it could be used as an appropriate biomarker for biological dosimetry. On the other hand, the up-regulation of is an indication of DNA repair following radiation exposure. According to linear no-threshold model (LNT) and the results obtained from this study, a very low dose of ionizing radiation could bring about adverse biological effects at molecular level in the irradiated person.
近年来，放射性药物在核医学中的应用大幅增加。在核医学科进行诸如心肌灌注成像等诊断程序后，患者通常会接受相当剂量的辐射。通常，暴露于低剂量电离辐射后预计会发生辐射诱导的DNA损伤。为了检测分子变化，必须采用高灵敏度技术。本研究的目的是使用定量实时聚合酶链反应（qRT-PCR）评估低剂量（低于10 mSv）γ射线对基因表达的影响。
从20名接受心肌灌注成像的志愿者患者中采集血样。给他们注射了不同剂量的锝-99m甲氧基异丁基异腈（Tc-MIBI）。之后，分离出外周血单个核细胞（PBMN），然后提取总RNA并逆转录为cDNA。最后，使用SYBR Green通过qRT-PCR技术测定着色性干皮病互补组A和铁氧化还原蛋白还原酶基因的表达水平。
在极低剂量电离辐射后获得了[基因名称未明确]和[基因名称未明确]的表达水平。观察到这两个基因均有显著上调，且每位患者的基因表达水平各不相同。如果考虑给药活性和放射敏感性的差异，观察到的差异是合理的。此外，性别和年龄在所研究基因的表达水平中未起显著作用。
辐射后[基因名称未明确]的上调揭示了该基因的高灵敏度水平；因此，它可作为生物剂量测定的合适生物标志物。另一方面，[基因名称未明确]的上调表明辐射暴露后DNA的修复。根据线性无阈模型（LNT）和本研究获得的结果，极低剂量的电离辐射可在受辐照者的分子水平上产生不良生物学效应。
