Establishment Of Prognostic Model And Prognostic Significance Of ATAD2 Protein Expression In Hepatitis B Virus Positive Hepatocellular Carcinoma

Objective: Hepatocellular carcinoma(HCC)is the most common type of primary liver cancer,and the major risk factor is hepatitis B virus(HBV)infection.As an area with a high incidence of hepatitis B in our country,the morbidity and mortality of HBV-HCC are both higher,which becomes an important public health problem threatening the health of residents.In this study,we aimed to identify the prognostic related genes of HBV-HCC patients using a public database,and establish a prognostic model to predict the prognosis of patients.The expression and clinical significance of key prognostic gene in HBV-HCC was analyzed.Methods: 1.Data sets from GEO database were used to identify differentially expressed genes(DEGs)between HBV-HCC samples and normal samples.Then,GO and KEGG enrichment analysis were carried out,and PPI network was established.The GSE14520 dataset was used as the training set to build a multi-gene prognostic risk model through multivariate Cox analysis,and the prediction ability of model was evaluated and verified.The risk score and clinicopathological features were combined to construct a nomogram to predict the overall survival rate of patients.2.Key prognostic gene in the model was identified,and the expression of key gene was analyzed in the dataset.Then,clinical tissue samples were collected for immunohistochemistry(IHC)to verify the differential expression in cancer and adjancent noncancerous tissues.The relationship between gene expression and prognosis of patients was analyzed.GSEA analysis was applied to explore potential biological signaling pathway,and the types and proportion of immune cells in tumor tissue were analyzed by CIBERSORT algorithm.Finally,the relationship between key gene expression and drug sensitivity was analyzed.Results: 1.There were 230 overlapping DEGs in the four datasets.The genes were mainly involved in KEGG signaling pathways such as retinol metabolism,fatty acid degradation,complement and coagulation cascades,glycolysis / gluconeogenesis,bile secretion.Simultaneously,the enriched GO functions include oxidoreductase activity,amide binding,blood microparticle,extracellular matrix,small molecule catabolic process,organic hydroxy compound metabolic process,etc.2.A prognostic risk model containing 6 genes(HBB,CD5 L,ZG16,CDC37L1,IGFBP3,ATAD2)was established to calculate the risk value of each patient.The results of training set and the validation set were consistent,Kaplan-Meier curves showed that the overall survival rate of high-risk group was poor(P < 0.05).The high AUC values in the 1,3and 5 years also indicate that the prediction accuracy of the model is good.3.Univariate and multivariate Cox regression analysis identified risk score and TNM stage as independent prognostic risk factors for HBV-HCC patients,and established a nomogram to predict the OS of patients,which has high accuracy and significant clinical benefit.4.In the GSE14520,the expression of ATAD2 in HBV-HCC tissues was up-regulated.IHC results also showed that the expression of ATAD2 protein in cancer tissues was higher than that in parcancer tissues,and was expressed in both cytoplasm and nucleus.ATAD2 expression was correlated with age and AFP level(P< 0.05),and was an independent risk factor for prognosis(HR=1.45,95%CI:1.15-1.81,P = 0.001).5.GSEA analysis showed that genes in high ATAD2 expression group were enriched in spliceosome,oocyte meiosis,protein export,homologous recombination,cell cycle pathways,and immune-related activities.However,genes in low ATAD2 expression group were enriched in glycolysis/gluconeogenesis pathway.6.Resting CD4 memory T cells,CD8 T cells,Macrophages M0 and Macrophages M2 had significant differences in high and low ATAD2 expression groups(P < 0.05).7.Our study found that ATAD2 expression was correlated to anticancer drugs such as sorafenib,vorinostat,gefitinib and sunitinib,etc.Conclusion: 6 genes prognostic signature had independent predictive ability in both the training set and the validation set,and the nomogram had good discriminative ability and high accuracy for predicting the prognostic risk.In addition,ATAD2,a key prognostic gene,was highly expressed in HBV-HCC tissues,which is an important prognostic marker and potential therapeutic target.