Bioinformatic Study Of Molecular Subtypes And Prognostic Models Of Th2 Cell-related Genes In Prostate Cancer

Objective:To screen Th2 cell-related genes of prostate cancer(PCa)based on bioinformatics,explore their biological functions,and construct a T helper 2 cells(Th2)-based immune clusters and prognostic model to analyze their relationship with the tumor microenvironment(TME),immune characteristics,clinical characteristics as well as immunotherapy.Methods:The RNA-seq data of 532 PCa cases from the cancer genome atlas(TCGA)database were uploaded to the Xcell website for immuno-infiltration analysis of PCa.Meanwhile,the DESeq2 R package was run to screen the differential expressed genes(DEGs)between PCa and normal tissues.Weighted correlation network analysis(WGCNA)was performed to obtain DEGs significantly associated with Th2 cells,and gene ontology(GO)and kyoto encyclopedia of genes and genomes(KEGG)were per-formed.The K-means algorithm constructed immune molecular clusters(C1 and C2)based on Th2 cells.Subsequently,the relationships between immune clusters and the prognosis,Gleason score,tumor stage,infiltration of immune cells,expression of im-mune checkpoint molecules,tumor mutation burden(TMB),tumor immune dysfunc-tion and exclusion(TIDE)score and immunophenotype score(IPS)of PCa patients were analyzed.The candidate Th2-related DEGs were further screened by the least ab-solute shrinkage and selection operator(LASSO)regression,a multivariate COX re-gression model was constructed,and the risk scores were calculated for each patient.Then,two external validation cohorts(GSE70768 and DKFZ-2018)were used to assess the stability of the model.Subsequently,we compared the differences in prognosis,Gleason score,tumor stage,TMB,and immune infiltration between high and low-risk groups of patients.Finally,the HPA database was used to validate the protein expression of key genes.The IMvigor210 immunotherapy cohort was used to assess the respon-siveness of different risk groups of PCa to immunotherapy.The correlations between key genes and drug sensitivity were analyzed by the GDSC and cell Miner databases to screen potential therapeutic agents.Results:Analysis of immune infiltration in PCa revealed that TME was charac-terized by low infiltration of immune cells and high infiltration of stromal cells.Anal-ysis of the relationship between immune cells and prognosis revealed that Th2 cells were significantly associated with Gleason score,stage,and the prognostic of PCa(P<0.05).One hundred and sixty-six Th2-related genes were obtained by WGCNA analysis,and functional enrichment of Th2-related genes was associated with the mi-totic process,cell cycle,p53 signaling pathway,cell senescence,etc.COX regression analysis further screened 33 genes with independent prognostic value for consensus clustering analysis,and finally,two immune molecular clusters C1 and C2 were ob-tained.The two immune clusters showed significant distinctions in the prognosis,im-mune cell infiltration,TMB,chemokines and chemokines receptors,immune-related molecules,MHC molecules,and immune checkpoint molecule expression of PCa(P<0.05).GSVA analysis revealed that C1 was associated with substance metabolic processes such as glycolysis and glycine metabolism.In contrast,C2 was associated with oncogenic processes such as cell cycle,mismatch repair,basal resection repair,and P53 signaling pathway.In addition,the eight-gene prognostic model(DEPDC1B,RAD54L,ASF1B,ASPN,CDCA5,CCDC110,MYO1H,CNIH2)constructed based on Th2 cells showed consistent stability in TCGA,GSE70768 and DKFZ-2018 cohorts.The different risk groups were significantly distinct in terms of biological function,TMB,tumor immune microenvironment,immune checkpoint molecule expression,and immunotherapy responsiveness(P<0.05).In addition,the risk score was an independ-ent prognostic factor for PCa.The high-risk score was associated with tumor stage,lymph node metastasis,Gleason score,recurrence and progression of PCa patients.In terms of immunotherapy,the high-risk group showed higher disease remission rates.Based on the GDSC database,bleomycins,17-AAG,PD-0325901,RDEA119,tramet-inib,and selumetinib were all found to have the highest correlation with the above eight genes,and based on the cell Miner database it was found to include methylprednisolone,nelarabine,6-Thioguanine,SNS-314,curcumin,and Zalcitabine were correlated with ASF1B,CDCA5,DEPDC1B,CNIH2 and RAD54L(r~2>0.3,P<0.01).Finally,immuno-histochemical staining based on the HPA database revealed that ASPN,CDCA5,RAD54L,and MYO1H showed strong staining in tumor tissues,and ASF1B and DEPDC1B showed low staining in both normal and tumor tissues.Conclusions:Th2 cells was significantly associated with the clinical progression and prognosis of PCa.Immune subtypes and prognostic risk models constructed based on Th2 cells showed significant differences in prognosis,tumor stage,Gleason score,immune checkpoint molecule expression,and immune cell infiltration in PCa.The risk score could be used as an independent prognostic factor for PCa patients and correlated with immunotherapy responsiveness.In conclusion,our study helps to understand the relationship between Th2 cells and tumors and provides ideas for clinical personalized immunotherapy.