Yao Z G, Cheng X K, Lin C H, Li J, Lyu B B, Li J M, Jing H Y, Qin Y J, Sun X C
Department of Pathology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China.
Zhonghua Zhong Liu Za Zhi. 2021 Aug 23;43(8):843-849. doi: 10.3760/cma.j.cn112152-20190717-00441.
To evaluate the value of next generation sequencing (NGS) in the genetic testing of Lynch syndrome. Immunohistochemical method was used to detect the expressions of DNA mismatch repair (MMR) proteins, including MutL homolog 1 (MLH1), PMS1 homolog 2 (PMS2), MutS homolog 2 (MSH2) and MutS homolog 6 (MSH6) in colorectal cancer, gastric cancer and endometrial cancer tissues collected from Shandong Provincial Hospital between 2016 and 2018. The genomic DNA of 45 patients who were suspected with Lynch syndrome was extracted from non-cancerous tissue paraffin samples, which were postoperatively confirmed by microscope. The mutations of 12 genes including MLH1 and MSH2 were detected using NGS. The germline mutant sites and significance were analyzed by bioinformatics technology and further confirmed by using Sanger sequencing. The immunohistochemical results showed that the 45 cases of suspected Lynch syndrome included 22 cases of MLH1 and PMS2 deficient expression, 16 cases of MLH2 and MSH6 deficient expression, and 7 cases of MMR proteins normal expression. The NGS result showed that 28 cases of adjacent sample from colon cancer patients included 4 cases of MLH1 pathogenic mutation, 1 case of suspected MLH1 mutation, 2 cases of MLH2 pathogenic mutation, 2 cases of suspected MLH2 mutation. No MMR gene mutation was found in adjacent samples of 6 cases of rectal cancer, 6 cases of gastric cancer and 7 cases of colorectal cancer with MMR normal expression. One case of MLH1 or MHL2 pathogenic mutation and one case of MLH1 suspected mutation was detected in adjacent samples of 5 cases of endometrial cancer. Moreover, NGS also detected many other genes mutations and unreported gene mutation sites. Pathogenic and suspected MLH1 and MSH2 mutations were verified by Sanger sequencing. High-throughput NGS is a quick, accurate and reliable technique to identify gene variants in suspected Lynch syndrome patients. It has a wide application prospect for gene testing of tumors associated with Lynch syndrome.
评估新一代测序（NGS）在林奇综合征基因检测中的价值。采用免疫组化方法检测2016年至2018年期间从山东省立医院收集的结直肠癌、胃癌和子宫内膜癌组织中DNA错配修复（MMR）蛋白的表达，包括MutL同源蛋白1（MLH1）、PMS1同源蛋白2（PMS2）、MutS同源蛋白2（MSH2）和MutS同源蛋白6（MSH6）。从术后经显微镜确诊的非癌组织石蜡样本中提取45例疑似林奇综合征患者的基因组DNA。应用NGS检测包括MLH1和MSH2在内的12个基因的突变。通过生物信息学技术分析种系突变位点及意义，并进一步用Sanger测序法进行验证。免疫组化结果显示，45例疑似林奇综合征患者中，MLH1和PMS2低表达22例，MLH2和MSH6低表达16例，MMR蛋白表达正常7例。NGS结果显示，28例结肠癌患者的相邻样本中，MLH1致病突变4例，疑似MLH1突变1例，MLH2致病突变2例，疑似MLH2突变2例。6例直肠癌、6例胃癌及7例MMR表达正常的结直肠癌患者的相邻样本中未发现MMR基因突变。5例子宫内膜癌患者的相邻样本中检测到1例MLH1或MHL2致病突变及1例疑似MLH1突变。此外，NGS还检测到许多其他基因突变及未报道的基因突变位点。通过Sanger测序验证了MLH1和MSH2的致病及疑似突变。高通量NGS是一种快速、准确、可靠的技术，可用于识别疑似林奇综合征患者的基因变异。在与林奇综合征相关的肿瘤基因检测中具有广阔的应用前景。
