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

项目概要/摘要： 液体活检（LB）是对容易接近的体内无细胞循环肿瘤DNA（ctDNA）的分析 液体来非侵入性地描绘实体瘤的分子景观。基于ctDNA的液体活检可 用于检测可操作的突变，监测对治疗的反应，并评估药物的出现。 阻力液体活检是特别有吸引力的非小细胞肺癌（NSCLC）作为激活突变 在表皮生长因子受体（EGFR）中赋予对酪氨酸激酶抑制剂敏感性（1）。但 用于检测ctDNA和相关基因组变化的液体活检技术的分析灵敏度是 受其与非肿瘤来源的无细胞DNA（cfDNA）相比的低浓度限制。2016年，FDA批准 Cobas EGFR Mutation Test v2使用血浆作为第一个诊断用液体活检检测。但 报告了检测2种最常见激活突变（外显子19缺失或外显子21）的灵敏度 在EGFR基因中，仅76.7%（2）存在突变。提高突变检测的灵敏度可以进一步 释放液体活检用于癌症诊断的潜力，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检分析平台 最接近于基于组织活检的肿瘤特异性ctDNA基因分型是未满足的临床需求。 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）血浆样本中EGFR突变的（uctDNA）分子 患者本NCI临床和转化探索性/开发研究R21申请旨在探索 并验证我们的假设，即NSCLC患者的血液和唾液样本中存在丰富的utDNA分子 这些uctDNA片段是额外的循环肿瘤靶点， 活检假设检验有两个具体目标。目的1是招募、入组250例NSCLC患者 来自加州大学洛杉矶分校医学中心（UCLAMC）肺病诊所和VA大洛杉矶（VA GLA） 肺病诊所将采集每例患者的血浆。目的2是验证 用于NSCLC液体活检的靶向uctDNA的uctDNA NGS测定。 总之，翻译和临床验证，靶向utDNA的液体活检可以打破新的 巩固和扩展先前的发现，以实现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.