Quantification of t(14;18) in the lymphocytes of healthy adult humans as a possible biomarker for environmental exposures to carcinogens
Quantification of t(14;18) in the lymphocytes of healthy adult humans as a possible biomarker for environmental exposures to carcinogens
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DOI：
10.1093/carcin/17.5.1013
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发表时间：
1996-05-01
期刊：
影响因子：
4.7
通讯作者：
Moore, MM
中科院分区：
文献类型：
--
作者：
Fuscoe, JC;Setzer, RW;Moore, MM
A t（14; 18）通过细胞遗传学和分子生物学分析，在85%的滤泡性淋巴瘤中发现染色体易位，这种重排通过易位到免疫球蛋白重链位点而使bcl-2原癌基因的表达失调，并且可能由非法V（D）J重组介导。我们已经开发了用于检测健康个体淋巴细胞中这种事件的定量巢式PCR方法，从外周血淋巴细胞中纯化基因组DNA，2.5 μ g（代表4 × 10（5）个细胞）用易位特异性引物扩增，扩增条件为单拷贝（如果存在）将产生可检测的PCR产物，对每个个体进行多次重复分析，然后使用泊松统计来估计易位突变频率，我们用这种方法检测了34名健康人的淋巴细胞DNA，发现t（14;通过测定易位连接处的DNA序列研究了易位的分子性质。在几个个体中，仅回收了同一易位事件的多个分离物，表明具有原始易位的细胞经历了克隆扩增。此外，显示在个体内发生多个独立易位。由于这种易位似乎是正常细胞发展为癌细胞的一个步骤，因此该测定法可用作环境致癌物暴露的效应生物标志物。
A t(14;18) chromosomal translocation is found in similar to 85% of follicular lymphomas by both cytogenetic and molecular analyses, This rearrangement deregulates expression of the bcl-2 proto-oncogene by translocation into the immunoglobulin heavy chain locus and is probably mediated by illegitimate V(D)J recombination, We have developed a quantitative nested PCR method for detecting this event in lymphocytes of healthy individuals, Genomic DNA is purified from peripheral blood lymphocytes, and 2.5 mu g (representing 4x10(5) cells) are amplified with translocation-specific primers under conditions in which a single copy, if present, will give a detectable PCR product, Multiple replicates are analyzed for each individual, and Poisson statistics are then used to estimate the translocation mutant frequency, We have examined lymphocyte DNA from 34 healthy individuals by this assay and found the frequency of cells with t(14;18) to range from < 0.8-96 x 10(-7), The molecular nature of the translocations has been investigated by determining the DNA sequence at the translocation junctions, In several individuals, multiple isolates of the same translocation event mere recovered, indicating that the cell with the original translocation had undergone clonal expansion, In addition, multiple independent translocations were shown to occur within an individual. Since this translocation appears to be one step in the progression of a normal cell to a cancer cell, this assay may have utility as an effects biomarker for environmental carcinogen exposure.