| Glioblastoma is a common clinical central nervous system malignant tumor,which accounts for about 50% of central nervous system malignant tumors.At present,the treatment of glioblastoma is mainly radiotherapy,chemotherapy and surgery.Despite the rapid development of medical technology in recent years,the prognosis of glioblastoma is still not optimistic.Therefore,it is of great importance to explore the molecular mechanism of the occurrence and development of glioblastoma and study effective therapeutic targets to improve the therapeutic effect of glioblastoma patients.TRIM（Tripartite Motif）family proteins play an important role in human physiological activities.Its protein structure is highly conserved,with RING domain,Bbox domain and coiled-coil domain successively from the N-end to the C-end.Initial studies have shown that TRIM family proteins are involved in a wide range of cellular activities,including proliferation,differentiation,programmed death,signal transduction,and intrinsic immunity.Recent studies have shown that TRIM family proteins may play an important role in the development and progression of tumors.However,the expression,function,molecular mechanism and clinical significance of TRIM38 in glioblastoma are still unclear at present,which requires further study and elaboration.This study aims to clarify the correlation between the expression of TRIM38 in glioblastoma and the survival of patients,as well as the specific effects of TRIM38 on glioblastoma cell proliferation,migration,invasion and other malignant phenotypes,and to study its molecular mechanism,in order to reveal the impact of TRIM38 on the biological characteristics of glioblastoma.To provide a new target for the precise treatment of glioblastoma.Methods:1.Firstly,the changes of DNA methylation sites of TRIM38 non-CpG island in normal samples and glioblastoma samples were analyzed in RAUH,TCGA,GSE60274 and GSE63347 databases.Secondly,the degree of DNA methylation of TRIM38 was detected in human glioblastoma cell lines.Finally,Pearson correlation analysis was used to evaluate the correlation between TRIM38 gene methylation and gene expression.2.The expression of TRIM38 in glioblastoma of different pathological grades was analyzed using GSE16011,CGGA,REMBRANDT database and immunohistochemistry.Secondly,the expression of TRIM38 in glioblastoma of human brain was detected in different cell lines.Finally,the relationship between TRIM38 expression and survival time of glioblastoma patients was analyzed in different databases.3.Bioinformatics was used to analyze the enrichment of immunoregulation-related functional gene clusters in samples with high expression of TRIM38.4.After transfection of trim38-Si RNA into U251 and A172 cell lines,cell proliferation assay was used to measure absorbance to evaluate cell viability.Transwell assay and cell scratch assay were used to evaluate the migration and invasion ability of cells.Cell apoptosis was evaluated by cell apoptosis assay.Cell cycle experiment was used to evaluate the cell cycle.5.GO enrichment analysis showed that the differentially expressed m RNA was involved in the production of type I interferon.KEGG pathway analysis revealed that the differentially expressed genes were mainly involved in DNA immune response related signaling pathways.After the expression of TRIM38 in U251 and A172 cell lines was down-regulated,the CGAS-STING signaling pathway was differentiated,and the pathway molecules with TBK1-IRF3 as the axis were significantly activated,while the pathway molecules with NF-κB as the axis were significantly inhibited.Results:1.Analysis of RAUH,TCGA,GSE60274,GSE63347 and other databases showed that,compared with normal brain tissue,DNA methylation sites of TRIM38 non-CPG island showed significant methylation loss in glioblastoma.Cytological experiments also found significant hypomethylation of TRIM38 non-CpG island DNA methylation sites in glioblastoma cell lines.Pearson correlation analysis showed that DNA methylation of TRIM38 gene was negatively correlated with gene expression.2.GSE16011,CGGA,REMBRANDT and other databases and immunohistochemical tests showed that TRIM38 expression was up-regulated in glioblastoma samples and increased with the increase of tumor grade.3.Bioinformatics analysis showed that glioblastoma with high expression of TRIM38 showed increased expression of pro-proliferation,anti-apoptosis,NF-κB signaling pathway and immunomodulatory related functional gene clusters,as well as increased infiltration of immune cells and secretion levels of immunosuppressive factors.4.After the expression of TRIM38 was down-regulated in U251 and A172 cell lines,the results of CCK8 assay,Transwell,cell scratches and cell cycle assay showed that the down-regulated TRIM38 could significantly inhibit the proliferation and migration of glioblastoma,but had no significant effect on cell cycle.The results of apoptosis assay showed that down-regulation of TRIM38 could significantly promote the apoptosis of glioblastoma cells.5.GO enrichment analysis showed that the differentially expressed m RNA was involved in the production of type I interferon.KEGG pathway analysis revealed that the differentially expressed genes were mainly involved in DNA immune response related signaling pathways.After the expression of TRIM38 in U251 and A172 cell lines was down-regulated,the CGAS-STING signaling pathway was differentiated,and the pathway molecules with TBK1-IRF3 as the axis were significantly activated,while the pathway molecules with NF-κB as the axis were significantly inhibited.Conclusions:1.Hypomethylation of TRIM38 non-CpG island DNA methylation sites in glioblastoma.2.Compared with normal brain tissue,the expression of TRIM38 in human glioblastoma tissue was significantly increased;Compared with normal brain astrocytes,the expression of TRIM38 in human glioblastoma cell lines was significantly increased.3.Downregulation of TRIM38 expression inhibits proliferation,invasion,migration and other malignant phenotypes of glioblastoma cell lines U251 and A172.4.TRIM38 may regulate the proliferation and invasion ability of glioblastoma cell lines by differentiating the regulation of CGAS-STING signaling pathway.5.TRIM38 is expected to become a potential target for clinical treatment of glioblastoma. |
