Ultra-short circulating tumor DNA (uctDNA) for liquid biopsy of non-small cell lung cancer

项目摘要/摘要： 液体活检是对易接近的人体内的无细胞循环肿瘤DNA(CtDNA)进行分析。 液体非侵入性地描绘了实体肿瘤的分子图景。基于ctDNA的液体活检可以 用于检测可操作的突变、监测治疗反应和评估药物的出现 抵抗。液体活检在非小细胞肺癌(NSCLC)中特别有吸引力，因为它是激活突变 在表皮生长因子受体(EGFR)中，酪氨酸激酶抑制剂具有敏感性(1)。然而， 液体活组织检查技术检测ctDNA和相关基因组变化的分析灵敏度为 与非肿瘤来源的无细胞DNA(CfDNA)相比，其浓度较低。2016年，FDA批准 Cobas EGFR突变测试v2使用血浆作为诊断用的第一个液体活组织检查。然而， 报道了检测2个最常见的激活突变(外显子19缺失或外显子21)的敏感性 在EGFR基因中)仅有76.7%(2)。提高突变检测的灵敏度可以进一步 释放液体活组织检查诊断癌症的潜力，包括早期检测以及 微小残留病的检测。提供检测灵敏度的液体活组织检查分析平台 最接近于基于组织活检的肿瘤特异性ctDNA基因分型是一种未得到满足的临床需求。 我们的初步研究表明存在一组新的超短循环肿瘤DNA 非小细胞肺癌(NSCLC)患者血浆中携带EGFR突变的uctDNA分子 病人。NCI临床和转译探索性/发育研究R21的应用是为了探索 并验证我们的假设，即在非小细胞肺癌患者的血液和唾液样本中存在丰富的uctDNA分子 这些uctDNA片段是额外的循环肿瘤靶点，将提高液体的敏感性 活组织检查。假设检验有两个具体目标。目标1是招募，招募250名非小细胞肺癌患者 加州大学洛杉矶分校医学中心(UCLAMC)肺部疾病诊所和退伍军人管理局大洛杉矶(VA GLA) 肺病诊所。将从每个患者身上收集血浆。目的2是验证其临床实用性。 以uctDNA为靶点的uctDNA NGS法在非小细胞肺癌液体活检中的应用 总之，以uctDNA为靶点进行液体活检的翻译和临床验证可以打破新的 为先前的发现奠定基础，并将其扩展到有影响力的新方向和临床应用。

Project Summary/Abstract: Liquid biopsy (LB) is the analysis of cell-free circulating tumor DNA (ctDNA) in readily-accessible body fluids to non-invasively profile the molecular landscape of solid tumors. Liquid biopsy based on ctDNA can be used to detect actionable mutations, monitor response to treatments and assess the emergence of drug resistance. Liquid biopsy is particularly attractive in non-small cell lung cancer (NSCLC) as activating mutations in Epidermal Growth Factor Receptor (EGFR) confer sensitivity to Tyrosine Kinase Inhibitors(1). However, the analytical sensitivity for liquid biopsy technologies for detecting ctDNA and associated genomic changes is limited by its low concentration compared to cell-free DNA (cfDNA) of non-tumor origin. In 2016, FDA approved the Cobas EGFR Mutation Test v2 using plasma as the first liquid biopsy test for diagnostic use. However, the reported sensitivity for the detection of the 2 most common activating mutations (exon 19 deletions or exon 21 substitutions) in the EGFR gene is only 76.7%(2). Improving the sensitivity of mutation detection could further unlock the potential of liquid biopsies for the diagnosis of cancer including earlier stage detection as well as detection of minimal residual disease. Liquid biopsy analytical platforms that deliver detection sensitivity closest to tissue biopsy-based genotyping of tumor-specific ctDNA is an unmet clinical need. Our preliminary study showed the existence of a novel group of ultrashort circulating tumor DNA (uctDNA) molecules with EGFR mutations in plasma samples from non-small cell lung cancer (NSCLC) patients. This NCI Clinical and Translational Exploratory/Developmental Studies R21 application is to explore and test our hypothesis that there are abundant uctDNA molecules in blood and saliva samples from NSCLC and these uctDNA fragments are additional circulating tumor targets that will improve the sensitivity of liquid biopsy. Two specific aims are in place for hypothesis testing. Aim 1 is to recruit, enroll 250 NSCLC patients that from UCLA Medical Center (UCLAMC) Pulmonary Disease Clinic and VA Greater Los Angeles (VA GLA) Pulmonary Disease Clinic. Plasma will be collected from each patient. Aim 2 is to validate clinical utility of uctDNA NGS assay targeting uctDNA for liquid biopsy of NSCLC. Together, the translational and clinical validations, targeting uctDNA for liquid biopsy can break new ground and extend previous discoveries towards impactful new directions and clinical applications.