Effects of prolonged storage of whole plasma or isolated plasma DNA on the results of circulating DNA quantification assays
Effects of prolonged storage of whole plasma or isolated plasma DNA on the results of circulating DNA quantification assays
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DOI：
10.1093/jnci/dji432
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发表时间：
2005-12-21
期刊：
影响因子：
--
通讯作者：
Pastorino, U
中科院分区：
文献类型：
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作者：
Sozzi, G;Roz, L;Pastorino, U
生物体液中分子标志物的分析已被提议作为癌症早期检测和监测的工具。已发现癌症患者的循环血浆DNA浓度高于非癌症对照组，但对标本保存对血浆DNA浓度的影响知之甚少。在这里，我们研究了血浆样本和纯化的血浆DNA的长期储存对实时聚合酶链式反应分析所确定的血浆DNA定量的重复性的影响。这项分析的样本来自34名肺癌患者和28名匹配的对照组受试者，这些受试者来自我们之前发表的病例对照研究中的200名受试者，以及参加肺癌筛查计划的117名非癌症吸烟者。对每个患者进行了两份血浆和分离DNA样本的评估，病例对照研究参与者的第一次评估和第二次评估之间的中位数为41个月，筛查研究参与者的中位数为9个月。DNA水平在两次评估之间以平均每年约30%的速度大幅下降。这些数据为合理规划储存的一系列生物样本的回溯性研究提供了有价值的信息，特别是在长期收集的情况下，就像在大型临床试验中可能发生的那样。
Analysis of molecular markers in biological fluids has been proposed as a tool for early detection and monitoring of cancer. Circulating plasma DNA concentrations have been found to be higher in cancer patients than in cancer-free control subjects, but little is known about the effect of specimen storage on plasma DNA concentrations. Here we investigated the impact of long-term storage of both plasma samples and purified plasma DNA on the reproducibility of plasma DNA quantification as determined using real-time polymerase chain reaction analysis. The analysis was performed on samples from a subset of 34 lung cancer patients and 28 matched control subjects selected from 200 subjects in our previously published case-control study and from 117 cancer-free smokers enrolled in a lung cancer screening program. Two samples of plasma and isolated DNA were assessed for each patient, with a median of 41 months between the first and second assessments for participants in the case-control study and 9 months for participants in the screening study. DNA levels declined substantially between the two assessments at an average rate of approximately 30% per year. These data provide valuable information for the rational planning of retrospective studies of banked series of biological samples, particularly if collected over a long period of time, as can occur in large clinical trials.