Radiation-induced chromosomal instability in BALB/c and C57BL/6 mice: The difference is as clear as black and white
Radiation-induced chromosomal instability in BALB/c and C57BL/6 mice: The difference is as clear as black and white
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DOI：
10.2307/3579411
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发表时间：
1997-02-01
影响因子：
3.4
通讯作者：
Ullrich, RL
中科院分区：
文献类型：
--
作者：
Ponnaiya, B;Cornforth, MN;Ullrich, RL
基因组不稳定性被认为是辐射诱发肿瘤发生的最早阶段。根据这一假设，对辐射诱发肿瘤高度敏感的个体应表现出增强的辐射诱发的不稳定性。BALB/c白色小鼠比C57 BL/6黑色小鼠对辐射诱发的乳腺癌敏感得多。在这项研究中，检查了这两种菌株的原代乳腺上皮细胞培养物在暴露于Cs-137 γ辐射后染色体畸变的“延迟”出现，作为辐射诱导的基因组不稳定性的衡量标准。正如预期的那样，从两个菌株的积极分裂培养物显示出快速下降的初始不对称畸变与时间postirradiation。然而，在16次群体倍增后，来自BALB/c小鼠的细胞表现出染色单体型断裂和间隙的频率显著增加，其在整个实验的时间过程中保持升高（28倍增）。C57 BL/6小鼠的细胞中没有观察到这种效应;在快速清除初始畸变后，辐照群体中染色单体型畸变的频率保持在或接近未辐照对照组的频率。这些结果表明，在体外的染色体损伤和乳腺肿瘤的易感性的潜在表达之间的相关性，并提供进一步的支持辐射诱导的不稳定性在肿瘤发生的过程中的核心作用。(C)1997年，辐射研究协会。
Genomic instability has been proposed to be the earliest step in radiation-induced tumorigenesis. It follows from this hypothesis that individuals highly susceptible to induction of tumors by radiation should exhibit enhanced radiation-induced instability. BALB/c white mice are considerably more sensitive to radiation-induced mammary cancer than C57BL/6 black mice. In this study, primary mammary epithelial cell cultures from these two strains were examined for the ''delayed'' appearance of chromosomal aberrations after exposure to Cs-137 gamma radiation, as a measure of radiation-induced genomic instability. As expected, actively dividing cultures from both strains showed a rapid decline of initial asymmetrical aberrations with time postirradiation. However, after 16 population doublings, cells from BALB/c mice exhibited a marked increase in the frequency of chromatid-type breaks and gaps which remained elevated throughout the time course of the experiment (28 doublings). No such effect was observed for the cells of C57BL/6 mice; after the rapid clearance of initial aberrations, the frequency of chromatid-type aberrations in the irradiated population remained at or near those of nonirradiated controls. These results demonstrate a correlation between the latent expression of chromosomal damage in vitro and susceptibility for mammary tumors, and provide further support for the central role of radiation-induced instability in the process of tumorigenesis. (C) 1997 by Radiation Research Society.