Effects of fission neutrons on human thyroid tissues maintained in SCID mice
Effects of fission neutrons on human thyroid tissues maintained in SCID mice
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DOI：
10.1016/j.mrgentox.2009.12.017
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发表时间：
2010-02-02
影响因子：
1.9
通讯作者：
Nomura, Taisei
中科院分区：
文献类型：
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作者：
Adachi, Shigeki;Ryo, Haruko;Nomura, Taisei
C57 BL 16 J-scid小鼠中格雷夫斯病患者的人甲状腺组织的形态和功能（甲状腺激素的分泌）得到了良好的维持。从核反应堆UTR-KINKI的裂变中子的甲状腺激素的血清水平降低，和甲状腺激素的变化由裂变中子比低LET辐射，X射线和Cs-137 γ射线，表明高的相对生物学效应（RBE; 6.5）的裂变中子。微阵列分析显示，约3%的基因在未暴露的甲状腺组织中的基因表达比来自同一患者的手术切除的甲状腺组织中的基因表达变化超过4倍，这可能是由于移植后不久氧气和营养供应困难。随着裂变中子（0.2-0.6戈伊）和137 Cs γ射线（1.0-3.0戈伊）剂量的增加，观察到基因表达相对于未暴露同期对照的剂量依赖性变化，并显示出较高的RBE（4.2）。此外，有些特定的基因在接受较高剂量辐射，特别是中子（0.4和0.6戈伊）照射的所有甲状腺组织中的基因表达变化超过4倍，但在较低剂量（0.2戈伊中子和1.0和2.0戈伊射线）照射的甲状腺组织中没有变化。这些基因与退化、再生有关。细胞凋亡和转录对人甲状腺组织中的中子损伤有特异性和非常敏感的反应。这是第一个实验报告，裂变中子可以诱发人体组织的一些形态和功能的障碍，显示出高的RBE对γ射线照射。这些结果有助于评估裂变中子和宇宙射线对人类的风险。(C)2010 Elsevier BV保留所有权利。
Morphology and function (secretion of thyroid hormone) of human thyroid tissues from Graves' disease patients are well maintained in C57BL16J-scid mice. Serum level of thyroid hormone was reduced by fission neutrons from the nuclear reactor UTR-KINKI, and changes in thyroid hormone by fission neutrons were bigger than those by low LET radiations, X-rays and Cs-137 gamma-rays, suggesting high relative biological effectiveness (RBE; 6.5) of fission neutrons. Microarray analyses revealed that about 3% of genes showed more than 4-fold change in gene expression in the unexposed thyroid tissues against surgically resected thyroid tissues from the same patient, probably due to the difficult oxygen and nutrient supply shortly after transplantation. Dose-dependent changes in gene expression against unexposed concurrent controls were observed with increasing doses of fission neutrons (0.2-0.6 Gy) and 137Cs gamma-rays (1.0-3.0 Gy) and showed high RBE (4.2). Furthermore, there were some specific genes which showed more than 4-fold change in gene expression in all the thyroid tissues exposed to higher doses of radiation, especially neutrons (0.4 and 0.6 Gy), but none at lower doses (0.2 Gy of neutrons and 1.0 and 2.0 Gy of gamma-rays). These genes related to degeneration, regeneration. apoptosis, and transcription, respond specifically and very sensitively to neutron injury in human thyroid tissues. This is the first experimental report that fission neutrons can induce some morphological and functional disorders in human tissues, showing high RBE against gamma-ray exposure. These results are useful to evaluate the risks of fission neutrons and cosmic rays to humans. (C) 2010 Elsevier B.V. All rights reserved.