p53 mutations in C57BL/6J murine thymic lymphomas induced by gamma-irradiation and N-methylnitrosourea.
p53 mutations in C57BL/6J murine thymic lymphomas induced by gamma-irradiation and N-methylnitrosourea.
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发表时间：
1992-07
期刊：
影响因子：
11.2
通讯作者：
Ormond Brathwaite;W. Bayona;Elizabeth W. Newcomb
中科院分区：
文献类型：
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作者：
Ormond Brathwaite;W. Bayona;Elizabeth W. Newcomb
用DNA烷基化剂n -甲基亚硝基脲或γ辐照处理的47只C57BL/6J动物胸腺组织的基因组DNA，采用单链构象多态性分析筛选p53突变的存在。原发性胸腺淋巴瘤中有13%（30例中有4例）检测到突变，但17例早期淋巴瘤中没有检测到突变。在n -甲基亚硝基脲（2 / 15）或γ辐照（2 / 15）诱导的肿瘤中p53突变的频率相同。突变发生在p53基因高度保守的外显子5,7和8。G:C到A:T的转变是常见的。在分析的4个肿瘤中，有一个在第7和第8外显子中包含两个p53突变。先前对同一肿瘤的研究表明，ras突变发生的频率很高（大于50%）（E. W. Newcomb et al., Cancer Res., 48:5514-5521, 1988）。我们的数据表明p53突变在本文研究的致癌物诱导的胸腺淋巴瘤中并不起主要作用。
Genomic DNA from thymus tissue obtained from 47 C57BL/6J animals treated with the DNA alkylating agent N-methylnitrosourea or gamma-irradiation were screened for the presence of p53 mutations by using the single strand conformation polymorphism assay. Mutations were detected in 13% (4 of 30) of primary thymic lymphomas but none of 17 early stage lymphomas. The frequency of p53 mutations was the same in tumors induced by N-methylnitrosourea (2 of 15) or by gamma-irradiation (2 of 15). Mutations occurred in the highly conserved regions of the p53 gene in exons 5, 7, and 8. G:C to A:T transitions were commonly observed. One of 4 of the tumors analyzed contained two p53 mutations in exons 7 and 8. A previous study of the same tumors showed that ras mutations occurred with high frequency (greater than 50%) (E. W. Newcomb et al., Cancer Res., 48:5514-5521, 1988). Our data suggest that p53 mutations do not play a major role in carcinogen-induced thymic lymphomas studied here.