Circulating Methylated SEPT9 DNA in Plasma Is a Biomarker for Colorectal Cancer
Circulating Methylated SEPT9 DNA in Plasma Is a Biomarker for Colorectal Cancer
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DOI：
10.1373/clinchem.2008.115808
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发表时间：
2009-07-01
影响因子：
9.3
通讯作者：
Lofton-Day, Catherine
中科院分区：
文献类型：
--
作者：
deVos, Theo;Tetzner, Reimo;Lofton-Day, Catherine
背景：血浆中SEPT9 DNA异常甲基化与结直肠癌的发生高度相关。我们报告了一种新的SEPT9生物标志物测定方法的开发及其在病例对照研究中的验证。这种基于血液的微创测试的发展可能有助于缩小目前筛查覆盖率的差距。方法：建立一种新的血浆SEPT9 DNA甲基化检测方法。该试验包括血浆DNA提取、亚硫酸氢盐转化DNA、亚硫酸氢盐转化DNA的纯化、实时PCR定量转化DNA和实时PCR测量SEPT9甲基化。在一项对97例确诊的结直肠癌患者和172例经结肠镜检查证实的健康对照者的研究中，确立了SEPT9检测的性能。在一项有90例病例和155例对照的独立盲法研究中，基于预定算法的性能得到了验证。结果：在亚硫酸氢盐转化后，SEPT9检测流程产生1.9 μ g/L （CI 1.3-3.0）循环血浆DNA，基因组DNA的回收率为45%-50%，与之前的研究相似。在训练研究中，SEPT9检测成功识别了72%的癌症，特异性为93%，在测试研究中，成功率为68%，特异性为89%。结论：循环甲基化的SEPT9 DNA，在新的(m)SEPT9检测中测量，是一种有价值的结肠直肠癌微创检测的生物标志物。新的检测方法适用于临床实验室的自动化和标准化使用。(C) 2009年美国临床化学学会
BACKGROUND: The presence of aberrantly methylated SEPT9 DNA in plasma is highly correlated with the occurrence of colorectal cancer. We report the development of a new SEPT9 biomarker assay and its validation in case-control studies. The development of such a minimally invasive blood-based test may help to reduce the current gap in screening coverage.METHODS: A new SEPT9 DNA methylation assay was developed for plasma. The assay comprised plasma DNA extraction, bisulfite conversion of DNA, purification of-bisulfite-converted DNA, quantification of converted DNA by real-time PCR, and measurement of SEPT9 methylation by real-time PCR. Performance of the SEPT9 assay was established in a study of 97 cases with verified colorectal cancer and 172 healthy controls as verified by colonoscopy. Performance based on predetermined algorithms was validated in an independent blinded study with 90 cases and 155 controls.RESULTS: The SEPT9 assay workflow yielded 1.9 mu g/L (CI 1.3-3.0) circulating plasma DNA following bisulfite conversion, a recovery of 45%-50% of genomic DNA, similar to yields in previous studies. The SEPT9 assay successfully identified 72% of cancers at a specificity of 93% in the training study and 68% of cancers at a specificity of 89% in the testing study.CONCLUSIONS: Circulating methylated SEPT9 DNA, as measured in the new (m)SEPT9 assay, is a valuable biomarker for minimally invasive detection of colorectal cancer. The new assay is amenable to automation an standardized use in the clinical laboratory. (C) 2009 American Association for Clinical Chemistry