分析循环游离DNA中的微卫星不稳定性和基因突变以监测结直肠癌进展。
Analyzing microsatellite instability and gene mutation in circulating cell-free DNA to monitor colorectal cancer progression.
作者信息
Fu Yun, Ye Yuedian, Liu Xiaorong, Zhu Guifang, Xu Yangwei, Sun Jingbo, Wu Hongmei, Feng Feiyan, Wen Zhihui, Jiang Shanshan, Li Yanyan, Zhang Qingling
机构信息
Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
Department of Pathology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
出版信息
Transl Cancer Res. 2021 Jun;10(6):2812-2821. doi: 10.21037/tcr-20-2762.
BACKGROUND
Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Detection of microsatellite instability (MSI) status and gene mutations may be useful for molecular targeted therapy. The liquid biopsy is a newly developed, non-invasive method for tumor diagnosis and monitoring. In this study, we evaluated the possible clinical value of liquid biopsy by analyzing MSI and gene mutation.
METHODS
Next-generation sequencing (NGS) was used to analyze MSI and gene mutation in circulating cell-free DNA (cfDNA) and tissue DNA extracted from 6 CRC patients' plasma and matched primary tumor tissue (MPTT) samples, respectively.
RESULTS
A total of 6 patients (4 male, 2 female) were included for analysis, whose stage ranges from stage I through stage III. NGS-based panel of 5 quasi-monomorphic microsatellite markers (MSI-NGS) BAT-25, BAT-26, NR21, NR24 as well as NR27, and 4 mismatch repair (MMR) genes (MSH2, MSH6, PMS2, MLH1) expressions assessed by immunohistochemistry (MMR-IHC) and NGS (MMR-NGS) were used to determine MSI status synergistically. Comprehensive analysis of NGS and IHC results showed that the overall incidences of MSI in plasma and MPTT samples from these patients were 1/6 and 2/6, respectively. 4 patients were defined as microsatellite stable (MSS) in both plasma and MPTT. In the above 6 patients, MSI-NGS detection in cfDNA accurately identified 1/2 of tissue high-level microsatellite instability (MSI-H) and 4/4 of tissue MSS for an overall accuracy of 5/6. Gene mutational profiles in these CRC patients' plasma and MPTT samples were analyzed by NGS. Tumor-specific gene mutations were detected in 2/6 of plasma and 4/4 of MPTT samples. The two mutation-positive plasma samples were from CRC patients at stage IIb and stage IIIc.
CONCLUSIONS
Analyzing MSI and gene mutation might be a non-invasive supplementary way to reveal the molecular characteristics of CRC.
背景
结直肠癌（CRC）是全球癌症相关死亡的第二大主要原因。检测微卫星不稳定性（MSI）状态和基因突变可能有助于分子靶向治疗。液体活检是一种新开发的用于肿瘤诊断和监测的非侵入性方法。在本研究中，我们通过分析MSI和基因突变评估了液体活检的潜在临床价值。
方法
采用下一代测序（NGS）分别分析6例CRC患者血浆中循环游离DNA（cfDNA）和匹配的原发性肿瘤组织（MPTT）样本中提取的组织DNA的MSI和基因突变情况。
结果
共纳入6例患者（4例男性，2例女性）进行分析，其分期范围从I期到III期。基于NGS的由5个准单态微卫星标记（MSI-NGS）BAT-25、BAT-26、NR21、NR24以及NR27组成的面板，以及通过免疫组织化学（MMR-IHC）和NGS（MMR-NGS）评估的4个错配修复（MMR）基因（MSH2、MSH6、PMS2、MLH1）表达被协同用于确定MSI状态。对NGS和IHC结果的综合分析表明，这些患者血浆和MPTT样本中MSI的总体发生率分别为1/6和2/6。4例患者在血浆和MPTT中均被定义为微卫星稳定（MSS）。在上述6例患者中，cfDNA中的MSI-NGS检测准确识别出1/2的组织高水平微卫星不稳定（MSI-H）和4/4的组织MSS，总体准确率为5/6。通过NGS分析这些CRC患者血浆和MPTT样本中的基因突变谱。在2/6的血浆样本和4/4的MPTT样本中检测到肿瘤特异性基因突变。两个突变阳性血浆样本分别来自IIb期和IIIc期的CRC患者。
结论
分析MSI和基因突变可能是一种揭示CRC分子特征的非侵入性补充方法。
Zotero 插件