Nakajima Madoka, Takeuchi Toru, Ogino Keiki, Morimoto Kanehisa
Department of Environmental and Preventive Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa 920-8640, Japan.
Jpn J Cancer Res. 2002 Mar;93(3):247-52. doi: 10.1111/j.1349-7006.2002.tb02165.x.
The object of this study is to investigate the relationship between a typical product of oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine (8OHdG), and mutagenesis in V79 cells through a molecular analysis of hypoxanthine-guanine phosphoribosyltransferase (hprt) gene mutants. We performed a direct sequencing analysis of the cDNA of mutants obtained after treatment with N,N'-bis(2-hydroxyperoxy-2-methoxyethyl)-1,4,5,8-naphthalenetetracarboxylic-diimide (NP-III) or riboflavin, each of which induces the formation of 8OHdG in cellular DNA upon UVA irradiation. The frequency of mutation after both treatments was no more than 2 to 5 times the control value. A considerable number of the mutants could not be amplified by RT-PCR, and this was also the case for the control mutants. Among the mutants analyzed, deletions and a TA-->AT transversion occurred predominantly. The reasons for the weak association of induction of 8OHdG with frequency of mutation and the possible mechanism of oxidative-stress-derived mutagenesis are discussed.
本研究的目的是通过对次黄嘌呤 - 鸟嘌呤磷酸核糖转移酶（hprt）基因突变体进行分子分析，研究氧化性DNA损伤的典型产物8 - 羟基 - 2'-脱氧鸟苷（8OHdG）与V79细胞诱变之间的关系。我们对用N，N'-双（2 - 羟基过氧 - 2 - 甲氧基乙基）-1,4,5,8 - 萘四羧酸二酰亚胺（NP - III）或核黄素处理后获得的突变体的cDNA进行了直接测序分析，这两种物质在紫外线A照射下均能诱导细胞DNA中8OHdG的形成。两种处理后的突变频率均不超过对照值的2至5倍。相当数量的突变体不能通过逆转录聚合酶链反应（RT - PCR）扩增，对照突变体也是如此。在所分析的突变体中，缺失和TA→AT颠换占主导地位。本文讨论了8OHdG诱导与突变频率之间弱关联的原因以及氧化应激衍生诱变的可能机制。
