Correlation between DNA alterations and p53 and p16 protein expression in cancer cell lines
Correlation between DNA alterations and p53 and p16 protein expression in cancer cell lines
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DOI：
10.1016/j.prp.2005.01.002
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发表时间：
2005-01-01
影响因子：
2.8
通讯作者：
Takano, Y
中科院分区：
文献类型：
--
作者：
Murai, Y;Hayashi, S;Takano, Y
为了研究DNA异常、p53和p16基因突变与甲基化和蛋白表达之间的相互作用，用Western blotting方法检测了20株癌细胞。P53的积聚与突变状态之间存在明显的相关性。在检测的20个细胞株中，有14个细胞株在外显子3-10存在P53纯合子突变，其中12个是错义突变，1个是无义突变，1个是移码突变。P53的过度表达总是与外显子6-8的错义突变有关。P53在第4-5外显子72密码子的错义突变或多态细胞中呈中度表达，而在野生型细胞、无义突变和移码突变细胞中无明显表达。P16启动子基因DNA异常与p16抑制基因蛋白表达显著相关。有6个细胞系过表达，2个细胞系呈中等表达，12个细胞系呈弱表达或无表达。40%(8/20)的细胞系p16蛋白甲基化缺失。在六个高表达p16蛋白的细胞株中，有两个可以在甲基化特异的RCP分析中用未甲基化和甲基化形式的引物进行扩增。两个引物均可扩增一株无明显表达的细胞系。当两个等位基因中的一个发生甲基化时，很容易发生p16蛋白的过度表达或消失。(C)2005年爱思唯尔股份有限公司。版权所有。
To investigate the interaction between DNA abnormalities, p53 and p16 gene mutations, and methylation and protein expression, 20 cancer cell lines were examined by Western blotting. A clear relation was found to exist between p53 accumulation and mutation status. Of 20 cell lines examined, 14 demonstrated p53 homozygous mutations in exons 3-10, including 12 missense mutations, one nonsense mutation, and one frameshift mutation. Overexpression of p53 was always linked to missense mutations in exons 6-8. Intermediate expression of p53 was noted in cells with missense mutations or polymorphism to proline at codon 72 in exons 4-5, whereas there was slight or no visible expression in wild type cells and in cells with nonsense and frameshift mutations. DNA aberration in the p16 promoter gene correlated significantly with protein expression of the p16 suppressor gene. Overexpression was noted in six cell lines, intermediate expression in two, and slight or no visible expression in 12. Methylation-caused disappearance of p16 protein was noted in 40% (8/20) of the cell lines. Of six cell lines overexpressing p16 protein, two could be amplified with primers for both unmethylated and methylated forms in a methylation-specific RCP analysis. One cell line with no visible expression could also be amplified with both primers. Overexpression or disappearance of p16 protein may readily occur when one of two alleles has been methylated. (c) 2005 Elsevier GmbH. All rights reserved.