Liver- and Colon-Specific DNA Methylation Markers in Plasma for Investigation of Colorectal Cancers with or without Liver Metastases
Liver- and Colon-Specific DNA Methylation Markers in Plasma for Investigation of Colorectal Cancers with or without Liver Metastases
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DOI：
10.1373/clinchem.2018.290304
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发表时间：
2018-08-01
影响因子：
9.3
通讯作者：
Chan, K. C. Allen
中科院分区：
文献类型：
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作者：
Gai, Wanxia;Ji, Lu;Chan, K. C. Allen
背景：在循环DNA池中测量来自不同组织的DNA可以提供关于许多病理情况存在的重要信息。然而，现有的涉及全基因组亚硫酸氢盐测序的方法相对昂贵，可能会给大规模分析带来挑战。方法：通过识别肝脏和结肠与其他组织相比存在的差异甲基化区域，我们确定了2个标记，并建立了相应的液滴数字聚合酶链式反应分析方法。对13例肝移植受者、40例肝癌患者和62例结直肠癌(CRC)患者(27例有肝转移，35例无肝转移)的血浆肝来源和结肠来源的DNA浓度进行了检测。结果：在肝移植受者中，用肝脏特异性甲基化标志物测定的肝源性DNA浓度与供者特异性等位基因的分数具有良好的相关性(Pearson R=0.99)。在肝癌患者中，肝源性DNA浓度与肿瘤最大大小呈正相关(Spearman R=0.74)。有肝转移和无肝转移的结直肠癌患者的血浆DNA浓度(中位数分别为138拷贝/毫升和4拷贝/毫升)高于30名健康对照组(26例未检测到浓度)。与分数浓度(ROC曲线下面积，0.85vs0.75)相比，肝源性DNA的绝对浓度能更好地区分有肝转移和无肝转移的结直肠癌患者。结论：应用Droplet数字聚合酶链式反应定量分析血浆DNA甲基化模式，可用于肿瘤的研究和器官移植的评估。这种方法对鉴别有和没有转移到其他器官的患者很有用。(C)2018年美国临床化学协会
BACKGROUND: Measurement of DNA derived from different tissues in the circulating DNA pool can provide important information regarding the presence of many pathological conditions. However, existing methods involving genome-wide bisulfite sequencing are relatively expensive and may present challenges for large-scale analysis.METHODS: Through identifying differentially methylated regions in the liver and colon compared with other tissues, we identified 2 markers and developed corresponding droplet digital PCR assays. Plasma concentrations of liver-derived and colon-derived DNA were measured for 13 liver transplant recipients, 40 liver cancer patients, and 62 colorectal cancer (CRC) patients (27 with and 35 without liver metastases).RESULTS: In liver transplant recipients, the fractional concentration of liver-derived DNA measured using the liver-specific methylation marker and donor-specific alleles showed good correlation (Pearson R = 0.99). In liver cancer patients, the concentration of liver-derived DNA correlated positively with the maximal dimension of the tumor (Spearman R = 0.74). In CRC patients with and without liver metastasis, the plasma concentrations of colon-derived DNA (median, 138 copies/mL and 4 copies/mL, respectively) were increased compared with the 30 healthy controls (26 had undetectable concentrations). The absolute concentration of liver-derived DNA provided a better differentiation between CRC patients with and without liver metastasis compared with the fractional concentration (area under ROC curve, 0.85 vs 0.75).CONCLUSIONS: Quantitative analysis of plasma DNA with tissue-specific methylation patterns using droplet digital PCR is applicable for the investigation of cancers and assessing organ transplantation. This approach is useful for differentiating patients with and without metastases to other organs. (C) 2018 American Association for Clinical Chemistry