肺腺癌诊断标志物筛选及免疫细胞浸润分析

Screening of diagnostic markers for lung adenocarcinoma and analysis of immune cell infiltration

用生物信息学方法筛选肺腺癌(Lung adenocarcinoma,LUAD)的诊断生物标志物,并分析肺腺癌中免疫细胞浸润情况。从GEO和TCGA数据库下载肺腺癌的表达数据集,利用R软件筛选肺腺癌与正常肺组织间的差异表达基因(DEGs),使用DAVID网站对DEGs进行GO及KEGG富集分析,使用STRING及Cytoscape等工具对DEGs构建蛋白相互作用网络并筛选hub基因;利用Kaplan⁃Meier法对DEGs进行生存分析,并对hub基因进行ROC分析筛选诊断生物标志物,利用GSEA预测有预后价值的基因参与的信号通路;并用Cibersort软件反卷积算法分析肺腺癌中免疫细胞浸润情况。共得到肺腺癌的234个DEGs,这些基因主要参与信号转导、物质代谢、免疫反应等相关信号通路;构建PPI网络筛选出的20个hub基因中8个存在预后价值(CCNA2、DLGAP5、HMMR、MMP1、MMP9、MMP13、SPP1、TOP2A),ROC分析中DLGAP5、SPP1值分别是0.703、0.706;DLGAP5、SPP1基因表达水平与肺腺癌组织浆细胞、未活化的CD4^(+)记忆细胞、调节T细胞、巨噬细胞M0、M1、M2及中性粒细胞浸润密切相关(P<0.05)。肺腺癌中DLGAP5、SPP1具有较高诊断价值且参与肺腺癌组织免疫细胞浸润;DLGAP5、SPP1基因可作为肺腺癌诊断的生物标志物,可为肺腺癌的靶向治疗研究提供新思路。

To screen diagnostic biomarkers for lung adenocarcinoma(LUAD)using bioinformatic approach and analyze immune cell infiltration in lung adenocarcinoma,expression datasets of lung adenocarcinoma were downloaded from GEO and TCGA databases.Differentially expressed genes(DEGs)between lung adenocarcinoma and normal lung tissues were screened using R software,and GO and KEGG enrichment analysis of DEGs was performed using DAVID tools.Protein interaction networks were constructed and hub genes of DEGs were screened using tools such as STRING and Cytoscape.Kaplan⁃Meier method was used for survival analysis of DEGs,ROC analysis of hub genes was performed to screen for diagnostic biomarkers,GSEA was utilized to predict the signaling pathways involved in genes with prognostic value,and Cibersort software was adopted to analyze immune cell infiltration in lung adenocarcinoma.A total of 234 DEGs of lung adenocarcinoma were obtained,which were mainly involved in signaling,substance metabolism,immune response,and other related signaling pathways.Eight of the 20 hub genes screened by PPI network had prognostic value(CCNA2,DLGAP5,HMMR,MMP1,MMP9,MMP13,SPP1,TOP2A),and according to ROC analysis.The values of DLGAP5 and SPP1 were 0.703 and 0.706 respectively.DLGAP5 and SPP1 gene expression levels were closely correlated to plasma cells in lung adenocarcinoma tissue,unactivated CD4^(+)memory cells,regulatory T cells,macrophage M0,M1,M2,and neutrophil infiltration(P<0.05).To conclude,DLGAP5 and SPP1 have high diagnostic values in lung adenocarcinoma and are involved in immune cell infiltration in lung adenocarcinoma tissues.DLGAP5 and SPP1 genes can be used as biomarkers for lung adenocarcinoma diagnosis and can provide new ideas for targeted therapy research of lung adenocarcinoma.