Relationship Between WGCNA-based CD8+ T-cell Related Gene Model And Prognosis,immune Microenvironment In Hepatocellular Carcinoma Patients

Objective:Immune checkpoint blockade(ICB)therapy is a promising treatment for hepatocellular carcinoma(HCC).However,it is limited by low response rates.Tumor-infiltrating immune cells(TIICs),specifically CD8~+T cells,in the tumor microenvironment(TME)are related to tumor immune responses and are potential predictors for immunotherapeutic and survival outcomes.Therefore,in this study,a new CD8~+T cell-related genes prognostic index(CD8T-RGPI)was established by weighted gene co-expression network analysis to evaluate the immune responses and prognostic outcomes of HCC.Methods:1、Using the TCGA databases,“Consensus TME”was used to estimate immune infiltrations in TCGA HCC and normal samples.At the same time,TIICs that were associated with OS outcomes were assessed by Univariable Cox proportional hazards models.2、WGCNA was performed to identify CD8+T cell-associated gene modules.Then,the CD8T-RGPI model was built by combining univariate Cox regression and the least absolute shrinkage and selection operator(LASSO)Cox regression analyses.And the ICGC LIRI-JP dataset from the HCCDB database was used as a cohort for external verification.3、“limma”in R was used for differential expression analysis on all genes to identify samples with high and low CD8T-RGPI scores.Gene set enrichment analysis(GSEA)was performed on the differential genes based on c2.cp.v7.2.symbols.gmt[Curated]gene sets.Single sample GSEA(ss GSEA)analysis was conducted on KEGG gene sets using“GSVA”in R.Finally,“Maftools”in R was used to analyse the quality and quantity of gene mutations in the two CD8T-RGPI subgroups.4、TIICs infiltration levels in the high and low risk groups were estimated by“Consensus TME”package.Then immune-related functions were analysed by the“GSVA”and“GSEABase”packages.Stromal and stromal scores were determined by the ESTIMATE algorithm.High and low risk group immune-suppressive cell types(i.e.,MDSC,TAM M2,CAF),T-cell exclusion and dysfunction scores were calculated on a web platform Tumour Immune Dysfunction and Exclusion,combined with four TME subtypes:Immune-enriched,fibrotic(IE/F);Immune-enriched,non-fibrotic(IE);Fibrotic(F);and Immune-depleted(D),were used to predict responses to immune checkpoint blockade.Results:1、Cytotoxic cells,NK cells,CD4~+T cells,CD8~+T cells,T cells gamma delta and endothelial cells were significantly associated with OS and are prognostic protective factors in HCC.And the infiltration abundance of these six TIICs was significantly decreased in HCC tissues compared with paracancerous tissue.2、The nomogram showed that the CD8T-RGPI model showed good predictive power for the prognosis of HCC patients in both the TCGA and ICGC databases.Moreover,CD8T-RGPI was elevated in patients with high T stage,M stage and TNM stage.3、Functional enrichment analysis found that focal adhesion,aerobic glycolysis,HIF1 transcription factor pathway,IL-4 and IL-13 signalling,as well as HSF1dependent transactivation were markedly.4、CD8T-RGPI high-risk HCC patients with high immune tolerance and immunosurveillance escape might have poor efficacies for ICB.The CD8T-RGPI low-risk HCC patients with high levels of immune infiltrations have good immunotherapeutic responses to ICB.Conclusions:1、CD8~+T cells are a prognostic protective factor in HCC.CD8T-RGPI is a novel biomarker with a good predictive outcome for HCC patients.2、CD8T-RGPI high-risk HCC groups was associated with the activation of tumor-related and immunosuppressive pathways,while the low-risk was associated with the activation of metabolism-related pathways.3、The response of the HCC patients to the ICB treatment was very well predicted,as assessed by the CD8T-RGPI model,which deserves further exploration and validation in the clinic.