【作者】 刘博；

【导师】 马克威；

【作者基本信息】 吉林大学 ， 肿瘤学， 2024， 硕士

【摘要】 背景及目的:多原发肺癌(MPLCs)因其复杂的异质性,对诊断和治疗造成了极大的挑战。目前,我们对于多原发肺癌的基因组与转录组特征的了解仍然有限。本研究旨在通过全外显子技术分析22例早期多原发肺癌样本中的基因突变信息以及拷贝数变异事件,以更深入地理解其基因组特征。此外,本研究还分析了公共数据库中多原发肺癌的单细胞转录组测序数据,以揭示早期多原发肺癌的转录组特征,从而期望能够为多原发肺癌的精准诊断和治疗提供新的视角和思路。研究方法:本研究全外显子测序部分收集2014年至2020年期间在吉林大学第一医院接受手术切除的10例多灶性肺癌患者,每个患者体内存在至少两个或两个以上不同的肿瘤病灶,将肿瘤组织与癌旁组织总共34例福尔马林固定石蜡包埋(FFPE)样本进行全外显子测序,同时选择GEO数据库中GSE200972数据集作为单细胞转录组测序分析对象。将以上两组数据进行数据处理及生物信息学分析,以研究早期多原发肺癌的基因组与转录组学特征。研究结果:1.全外显子突变分析提示本研究中单个患者的不同病灶其共有突变的数量和比例极低,表明每个患者体内的病变是均为原发病变。2.突变特征分析使用贝叶斯非负矩阵分解算法识别出样本三个突变特征,即signature 6、signature 4和signature 40。其中signature 6的比例最高。并且在其中的一个患者的两个肿瘤样本均显示signature 4的比例最高。3.部分样本中存在染色体14q13.3上的NKX2-1/TTF-1和17q12上的ERBB2/HER2基因拷贝数扩增,以及位于9p21.3的CDKN2A与位于19p13.3的STK11/LKB1拷贝数缺失。4.转录组富集分析提示在GSE200972数据集中存在4个在肿瘤样本中发生激活的通路,分别为MYC相关通路、P53通路、氧化磷酸化通路、糖酵解通路,以及一个抑制通路:TNFα/NF-k B通路。5.在GSE200972数据集中共鉴定出8个关键基因,分别为CXCL8、GAPDH、CXCR4、KRAS、CXCL1、CCL2、MUC1、SPP1。其中GAPDH与SPP1在GEPIA肺腺癌数据库中表达升高,同时生存分析表明,GAPDH与SPP1高表达患者总生存期短于低表达患者。结论:1.多原发肺癌中不同病灶间具有很强的基因异质性,而且除常见的驱动突变外存在其它的基因组改变事件共同导致肿瘤的发生发展。2.多原发肺癌中同一个体不同病灶间可以存在相似的突变特征。3.在早期多原发肺癌中既有原癌基因相关通路的激活,也有抑癌基因激活起拮抗肿瘤进展作用,同时在早期多原发肺癌中存在沃伯格效应。4.肺腺癌中一些基因表达升高通常提示有相对较差的预后。更多还原

【Abstract】 Background and objective:Multiple primary lung cancers(MPLCs),due to their complex heterogeneity,pose significant challenges in diagnosis and treatment.Additionally,our understanding of the genomic and transcriptomic characteristics of MPLCs is limited.This study utilized whole exome sequencing to analyze gene mutation information and copy number variation events in 22 early-stage MPLC samples.It also examined single-cell transcriptome sequencing data from public databases to explore the molecular characteristics of early-stage MPLCs.It is anticipated that these findings will offer new perspectives and insights for the precise diagnosis and treatment of multiple primary lung cancers.Methods:This study collected 34 formalin-fixed paraffin-embedded(FFPE)samples from10 patients with multifocal lung cancer who underwent surgical resection at the First Hospital of Jilin University between 2014 and 2020.Each patient had at least two or more different tumor lesions.Whole exome sequencing was performed on these samples.Additionally,the GSE200972 dataset from the GEO database was selected for single-cell transcriptome sequencing analysis.Both sets of data were processed and analyzed bioinformatically to study the genomic and transcriptomic characteristics of early-stage MPLCs.Results:1.Whole exome mutation analysis indicated that the number and proportion of shared mutations in different lesions of individual patients in this study were extremely low,further suggesting that each lesion within a patient is an independent primary lesion.2.Mutation characteristic analysis using Bayesian non-negative matrix factorization identified three mutation signatures in the samples: signature 6,signature4,and signature 40,with signature 6 being the most prevalent.Additionally,both tumor samples from one patient showed the highest proportion of signature 4.3.Some samples exhibited copy number amplification of NKX2-1/TTF-1 on14q13.3 and ERBB2/HER2 on 17q12,as well as copy number deletions of CDKN2 A on 9p21.3 and STK11/LKB1 on 19p13.3.4.Transcriptome enrichment analysis indicated that four pathways were activated in tumor samples in the GSE200972 dataset: MYC-related pathway,P53 pathway,oxidative phosphorylation pathway,glycolysis pathway,and one inhibited pathway:TNFα/NF-k B pathway.5.In the GSE200972 dataset,a total of 8 key genes were identified: CXCL8,GAPDH,CXCR4,KRAS,CXCL1,CCL2,MUC1,and SPP1.Among these,GAPDH and SPP1 showed elevated expression in the GEPIA lung adenocarcinoma database.Survival analysis indicated that patients with high expression of GAPDH and SPP1 had shorter overall survival compared to those with low expression.Conclusions:1.Different lesions within MPLCs exhibit strong genetic heterogeneity,and in addition to common driver mutations,other genomic changes contribute to tumor development and progression.2.Similar mutation characteristics can exist between different lesions within the same individual in MPLCs.3.In MPLCs,pathways related to oncogenes are activated,as well as tumor suppressor genes,playing a counteracting role in tumor progression,also there is a Warburg effect in early stage multiple primary lung cancers.4.Elevated expression of certain genes in lung adenocarcinoma is typically indicative of a relatively poor prognosis.更多还原