基于生物信息学对食管鳞状细胞癌新辅助放化疗敏感性生物标志物的发掘

Discovery of Biomarkers of Esophageal Squamous Cell Carcinoma Sensitive to Neoadjuvant Chemoradiotherapy Based on Bioinformatics

目的:通过生物信息学方法筛选能预测食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)对新辅助放化疗(neoadjuvant chemoradiotherapy,NCRT)具有敏感性的生物标志物。方法:利用GEO数据库中的数据集GSE45670,采用多种生物信息学方法,包括蛋白互作(protein-protein interaction,PPI)网络、差异表达基因(differentially expressed genes,DEGs)分析和加权基因共表达网络分析(weighted gene co-expression network analysis,WGCNA),筛选出与食管鳞癌放化疗敏感性相关的生物标志物。同时,收集2017年至2021年期间在四川省肿瘤医院诊断为ESCC的26例患者的活检样本,采用免疫组化方法进行生物标志物的初步验证;通过Kaplan-Meier法利用TCGA数据库中ESCC相关数据分析生物标志物与ESCC预后相关性。结果:筛选出350个DEGs,与WGCNA中紫色模块的159个基因进行交叉获取了重叠的5个基因(AKR1C3、GPX2、RRBP1、GSTM3、AKR1C1),结合PPI网络所获得的1个核心基因(MMP9),最终筛选出6个候选基因。免疫组化分析验证显示,食管鳞癌患者对NCRT不敏感组织的细胞膜上AKR1C3蛋白表达上调,对NCRT敏感组织的细胞质上MMP9表达上调。ESCC患者中AKR1C3/1基因高表达组的生存率低于低表达组。结论:MMP9和AKR1C3蛋白表达水平差异与ESCC患者对NCRT敏感性具有一定的相关性。

Objective:To screen the biomarkers that can predict the sensitivity of esophageal squamous cell carcinoma(ESCC)to neoadjuvant chemoradiotherapy(NCRT)by bioinformatics.Methods:Gene microarray data(GSE45670)was downloaded from the Gene Expression Omnibus(GEO)database.We identified biomarkers using various analyses including protein-protein interaction(PPI)networks,differentially expressed genes(DEGs)and weighted gene co-expression network analyses(WGCNA).Meanwhile,we collected 26 biopsy samples from ESCC patients in Sichuan Cancer Hospital and used immunohistochemistry to confirm the biomarkers of esophageal squamous cell carcinoma sensitive to NCRT.The correlation between biomarkers and the prognosis of ESCC was performed by the Kaplan-Meier method based on data from TCGA database.Results:5 genes were obtained from where 350 DEGs and 159 genes from the purple module in WGCNA overlapped,and were combined with 1 core gene obtained from PPI network.Finally,6 candidate genes were screened.Immunohistochemical analysis showed that AKR1C3 protein expression was up-regulated on the cell membrane of NCRT-insensitive tissue in ESCC patients,and MMP9 expression was up-regulated on the cytoplasm of NCRT-sensitive tissue in ESCC patients.The survival rate of the high AKR1C3/1 expression group was lower than that of the low AKR1C3/1 expression group in ESCC patients.Conclusion:There is a correlation between the up-or down-regulation of MMP9 and AKR1C3 and the sensitivity of ESCC patients to NCRT.