The bacterial characteristic genes and their functions in primary glioblastomas
Objective To analyze the bacteria composition in primary tumor tissues of patients with glioblastomas(GBM)and to study the function and mechanism of intratumoral bacteria-related characteristic genes in GBM.Methods A total of 152 cases of primary GBM were analyzed based on the public data of bacteria-related genes within tumors based on The Cancer Genome Atlas(TCGA).According to the median overall survival time of GBM patients,they were divided into a low survival group(78 cases)and a high survival group(74 cases).Differences in α diversity between groups were evaluated using rank sum tests.Non-metric multidimensional scaling(NMDS)analysis and principal co-ordinates analysis(PCoA)were used to assess the differences in β diversity between groups.Linear discriminant analysis(LDA)was used to compare bacteria-related characteristic genes in two groups of GBM samples.According to the relative abundance of different bacteria-related characteristic genes,152 patients were divided into high abundance group and low abundance group.Kaplan-Meier method was used to analyze the difference in survival rate between the high abundance group and the low abundance group.Gene ontology(GO)functional annotation of biological processes and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis were performed for significantly upregulated genes in high-abundance bacterial-related characteristic gene samples associated with better prognosis.Tumor immune microenvironment landscape was analyzed by TCGA transcriptome sequencing data set,and the correlation between immune cell infiltration content and prognostic related bacterial characteristic genes was analyzed by Mantel test.All data were analyzed using R software,and P＜0.05 was considered statistically significant.Results A total of 252 bacteria-related characteristic genes were identified in 152 GBM tissues,of which 234 were present in both the low survival group and the high survival group,8 were present only in the low survival group and 10 were present only in the high survival group.NMDS and PCoA analyses showed significant statistical differences in β diversity between the two groups.LDA analysis showed that bacteria-related characteristic genes in tumor tissues was different between the high survival group and the low survival group(P＜0.05).The abundance of Bacteroides fragile-related characteristic genes was higher in the high survival group(P＜0.05),and was positively correlated with the overall survival of patients(x2=4.13,P＜0.05).Functional enrichment analysis showed that genes related to immune pathway were highly expressed in tumor tissues of patients with higher abundance of Bacteroides fragilis-related characteristic genes(P＜0.05).Mantel test analysis results showed that the abundance of Bacteroides fragilis-related characteristic genes in primary GBM tumor tissues was positively correlated with M1 macrophage infiltration(P＜0.05).Conclusion Bacteroides_fragilis-related characteristic genes are more abundant in primary tumors from high survival GBM patients and impact the tumor immune microenvironment.
GlioblastomaBacteria related geneIntratumoral bacteriTranscriptome
NETL
NSTL
万方数据
