基于肿瘤基质评分的胃癌预后基因分析  

Analysis of prognosis-related genes of gastric cancer based on tumor stromal score

作　　者：罗安 朱欣彦[1] 胡晔东[1] 刘雁冰[1] 冉晨曦 刘菲[1] LUO An;ZHU Xin-yan;HU Ye-dong;LIU Yan-bing;RAN Chen-xi;LIU Fei(Dept.of Gastroenterology,East Hospital,Tongji University School of Medicine,Shanghai 200120,China)

机构地区：[1]同济大学附属东方医院消化内科,上海200120

出　　处：《同济大学学报（医学版）》2020年第4期418-425,共8页Journal of Tongji University(Medical Science)

基　　金：国家自然科学基金(81970358)。

摘　　要：目的分析比较不同肿瘤基质评分胃癌患者的基因表达特征,鉴定与评分相关的胃癌预后基因,以期为临床胃癌诊断和预后提供更精准的手段。方法从癌症基因组图谱数据库(the cancer genome atals,TCGA)下载胃癌的临床资料和组织转录组测序(ribonucleic acid sequencing,RNAseq)表达数据。从基质免疫评估数据库(estimation of stromal and immune cells in malignant tumor tissues using expression data,ESTIMATE)网站下载TCGA数据库中胃癌患者基质评分信息。获取患者的临床信息、RNAseq表达谱、基质评分。按照基质评分的高低分为高基质评分组和低基质评分组,分析基质评分与胃癌预后的关系。用R语言DEseq2包进行标准化处理和差异分析;WGCNA(weight correlation network analysis,WGCNA)包筛选与基质评分密切相关的差异基因;单因素COX风险比例回归模型(COX proportional model,COX)初步筛选基质评分密切相关基因中与胃癌预后相关的基因;LASSO(least absolute shrinkage and selection operator,LASSO)回归模型筛选出其中影响胃癌预后的关键基因,计算最小λ值;多因素COX回归分析构建关键基因胃癌预后模型,并量化基因表达量与患者生存时间的关系;模型内部绘制关键基因的生存曲线。最后通过其他公共数据库(KM-plotter数据库和Oncomine数据库)验证这些基因在胃癌大样本的表达和预后。结果基质评分越高的患者表现为预后更差(P<0.05)。对患者的RNA-seq差异表达分析筛选得到1581个差异表达基因;从中通过WGCNA筛选出1015个基因与胃癌基质评分密切相关;单因素COX回归选出377个基因与胃癌患者预后相关(P<0.05);LASSO回归筛选出12个与胃癌预后相关的关键基因,最小λ=12;多因素COX回归分析显示该模型C指数为0.68,3年生存期和5年生存期的预测值基本贴合实际值,3年生存期曲线下面积(area under the curve,AUC)为0.693,5年生存时间AUC为0.725。12个基因中,ACTA1、ADAObjective To identify the prognosis-related genes of gastric cancer based on bioinformatics analysis.Methods Clinical and tissue transcriptome sequencing(RNAseq)data of gastric cancer were downloaded from the cancer genome atlas(TCGA).The gastric cancer stromal scores of patients was downloaded from the database of estimation of stromal and immune cells in malignant tumor tissues using expression data(ESTIMAT).The clinical information,RNAseq expression profile and tumor stromal score of the patients were integrated.The relationship between stromal score and the prognosis of gastric cancer was analyzed.The DEseq2 package was used for standardization and differential expression analysis of the RNAseq matrix data;the WGCNA(weight correlation network analysis)package was used to select the gene module which was closely related to stromal score among the differential expression genes.Uunivariate COX regression model was used to screen out the genes closely associated with prognosis of gastric cancer;Lasso(least absolute shrinkage and selection operator)regression model was used for screening out the key genes influencing the prognosis of gastric cancer,and the minimum λ of the model was calculated.The multivariate COX regression analysis was performed to construct the prognostic model of key genes in gastric cancer and to analyze the relationship between gene expression and survival time of patients.The survival curves of key genes were generated.Finally,the expression and prognosis of these genes were verified in large samples of gastric cancer from other public databases(km-plotter database and Oncomine database).Results The prognosis of gastric cancer patients with high stromal score were significantly worse that of that of patients with low score(P<0.05).Based on RNAseq data between gastric cancer patients with high and low stromal scores,1581 differentially expressed genes were screened out.WGCNA picked out a gene module containing 1015 genes which were closely related to the stromal score of gastric cancer.The

关 键 词：胃癌 高通量测序 癌症基因组图谱数据库 权重共表达分析 预后基因 

分 类 号：R573[医药卫生—消化系统]