细胞焦亡分型和APOD预测胃癌患者预后作用的生物信息学分析

Bioinformatics analysis on predition effect of subtypes of cell pyroptosis and APOD on prognosis of gastric cancer patients

目的:寻找胃癌(GC)患者的预后标志物,实现GC的早诊早治,为提高GC患者的生存率提供依据。方法:从癌症基因图谱(TCGA)数据库和GSE84437数据集下载407和433例GC患者的临床数据和转录组数据并合并,根据细胞焦亡相关基因的表达水平和ConsensusClusterPlus数据包对GC组织样本进行聚类分型,分为A分型(342例)和B分型(465例),将GC患者按照载脂蛋白D(APOD)水平分为低表达组和高表达组。采用survminer数据包比较不同分型患者预后的差异,采用ssGSEA算法比较不同分型患者免疫浸润的差异,采用Lasso回归和Cox回归构建GC患者预后风险模型,对模型基因进行临床性状过滤,采用公共数据库分析APOD在癌旁正常组织和GC组织中表达水平的差异,采用基因富集分析(GSEA)分析APOD的京都基因与基因组百科全书(KEGG)信号通路富集情况,采用CIBERSORT算法评估免疫细胞含量并分析其与APOD表达的相关性,采用在线网站分析APOD的药物敏感性。结果:2种细胞焦亡分型患者预后比较差异有统计学意义(P=0.002);A分型患者中22种免疫细胞含量均高于B分型(P<0.01);不同年龄(P<0.01)、N分期(P=0.04)患者2种细胞焦亡分型百分率差异有统计学意义。公共数据库分析,在GC患者肿瘤组织中APOD表达水平低于癌旁正常组织;生存分析,高表达组GC患者预后较低表达组差;临床相关性分析,不同T分期患者APOD表达水平比较差异有统计学意义(P<0.05);GSEA分析,高表达组在细胞黏附通路、白细胞内皮迁移通路和缝隙连接通路富集;免疫浸润分析,高表达组中滤泡辅助T淋巴细胞、CD4+记忆激活T淋巴细胞、静息自然杀伤(NK)细胞和中性粒细胞含量少于低表达组;APOD与CXC趋化因子配体12(CXCL12)(r=0.500,P<0.01)、转化生长因子B1(TGFB1)(r=0.313,P<0.01)、CC趋化因子配体19(CCL19)(r=0.518,P<0.01)和CX3C趋化因子受体1(CX3CR1)(r=0.444,P<0.01)呈正相关关系;药物敏感性分析,APOD与AZD-7762、KW-2449和TG-101348呈正相关关系(0<r<0.3,P<0.05)。结论:依据焦亡分型可以较好地评估GC患者的预后;APOD可以成为GC新的预后标志物和治疗靶点。

Objective:To seek the prognostic markers for the gastric cancer(GC)patients,and to achieve the early diagnosis and treatment of GC,and to provide the evidence for improving the survival rate of the GC patients.Methods:The clinical data and transcriptome data of 407 and 433 GC patients were downloaded from the The Cancer Genome Atlas(TCGA)Database and GSE84437 Dataset,and merged;the GC tissue samples were classified and typed based on the expression levels of cell death-related genes and the ConsensusClusterPlus Package,and were divided into type A(342 cases)and type B(465 cases);the GC patients were divided into low expression group and high expression group according to the expression level of apolipoprotein D(APOD);the survminer Data Package was used to compare the differences in prognosis of the patients with different subtypes;the ssGSEA Algorithm was used to compare the differences in immune cell infiltration of the patients with different subtypes;Lasso regression and Cox regression were used to construct the prognostic risk model for the GC patients;the clinical characteristics of model genes were filtered;the differential expression of APOD in adjacent normal tissue and GC tissue was analyzed by Public Databases;GSEA analysis was used to assess the Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment of APOD;the CIBERSORT Algorithm was used to evaluate the correlation between the content of immune cells and expression of APOD;the online website was used to analyze the drug sensitivity of APOD.Results:There was statistically significant difference in prognosis of the patients with two subtypes of cell pyroptosis(P=0.002);the levels of 22 kinds of immune cells of the patients with type A were higher than those with type B(P<0.01);there were statistically significant differences in the percentages of two subtypes of cell pyroptosis of the patients with different ages(P<0.01)and N stages(P=0.04).The Public Databases analysis results showed that the expression of APOD in tumor tissue of the GC patients was lower than that in adjacent normal tissue;the survival results showed that compared with low expression group,the patients in high expression group had poorer prognosis;the clinical correlation analysis results showed that there were significant differences in the APOD expression of the patients with different T stage(P<0.05);the GSEA analysis results showed that high expression group enriched in the cell adhesion pathways,leukocyte endothelial migration pathways,and gap junction pathways;the immune infiltration analysis results showed that the contents of follicular helper T lymphocytes,CD4+memory activated T lymphocytes,resting NK cells,and neutrophils in high expression group were lower than those in low expression group;APOD had positive correlations with CXC chemokine ligand 12(CXCL12)(r=0.500,P<0.01),transforming growth factor beta 1(TGFB1)(r=0.313,P<0.01),chemokine CC chemokine ligand 19(CCL19)(r=0.518,P<0.01),and CX3C chemokine receptor 1(CX3CR1)(r=0.444,P<0.01);the drug sensitivity analysis results showed that there were positive correlations between APOD and AZD-7762,KW-2449,and TG-101348(0<r<0.3,P<0.05).Conclusion:Cell pyroptosis subtypes can effectively evaluate the prognosis of the GC patients;APOD can be regarded as the novel prognostic marker and therapeutic target for GC.