Lung Cancer, DNA Methylation, and Liquid Biopsy

摘要 非小细胞肺癌（NSCLC）是一种预后较差的恶性肿瘤。主要 影响因素包括疾病早期诊断的障碍和 目前可用的方法来监测治疗反应。液体活检或血液样本， 提供了所有癌性病变（原发性和转移性）的表观遗传景观。此外，它还提供 有机会系统地监测癌症疾病的定量循环无细胞 DNA（cfDNA）已显示与肿瘤负荷相关。液体活检作为一种 肺癌患者的诊断和预后工具正逐渐成为一种有吸引力的方法， 临床常规实践，因为它是无创的，可以很容易地重复。我们先前报道 普通人特异性高甲基化新DNA甲基化位点的计算机识别 可以作为表观遗传生物标志物的癌症。使用独特的DNA甲基化特异性qPCR 通过这种方法，我们在临床上测试了一组这些癌症特异性基因座上提取的无细胞DNA（cfDNA）， 来自健康对照和NSCLC患者的血液样品的血浆部分。这些DNA 甲基化生物标志物以高灵敏度和特异性区分肺癌病例和对照 (AUC= 0.96）。在明确定义的患者队列中，我们将评估DDX-Sentinel的性能 生物标志物：1）在不确定的肺结节中识别癌症并通过CT筛查识别 和2）评价DDX-哨兵生物标志物监测反应的能力 手术切除这些研究将使我们能够在未来进行II期申报。

ABSTRACT Non-small cell lung cancer (NSCLC) remains a devastating disease with overall poor prognosis. Major contributing factors include obstacles to diagnosing the disease early in its course and limitations in currently available approaches to monitor therapeutic response. A liquid biopsy, or blood sample, can provide the epigenetic landscape of all cancerous lesions (primary and metastases). In addition, it offers the opportunity to systematically monitor cancer disease as the quantification of circulating cell-free DNA (cfDNA) has been shown to correlate with tumor burden. The practice of liquid biopsy as a diagnostic and prognostic tool in lung cancer patients is gradually becoming an appealing approach in the clinical routine practice, since it is noninvasive and can be easily repeated. We previously reported in silico identification of novel DNA methylation loci specifically hypermethylated in common human cancers that could be used as epigenetic biomarkers. Using a unique DNA methylation specific qPCR approach, we clinically tested a group of these cancer-specific loci on cell-free DNA (cfDNA) extracted from the plasma fraction of blood samples from healthy controls and NSCLC patients. These DNA methylation biomarkers distinguish lung cancer cases from controls with high sensitivity and specificity (AUC = 0.96). In well-defined patient cohorts, we will assess the performance of our DDX-Sentinel biomarkers to: 1) Identify cancer in indeterminate pulmonary nodules and identified by CT screening of high-risk individuals and 2) Evaluate the capability of DDX-Sentinel Biomarkers to monitor response to surgical resection. These studies will position us for a future Phase II submission.