Construction Of A Prediction Model Related To The Glioblastoma Microenvironment And The Expression And Mechanism Of C1R

Backgroud and purpose:Glioblastoma(GBM)is a common and malignant intracranial tumour with the highest proportion and lethality.It is characterized by invasiveness and heterogeneity.However,the currently available therapies are not curative.Growing evidence suggests that immunotherapy targeting the tumor microenvironment is an effective treatment for GBM;however,current clinicopathological informative features do not provide accurate guidance for immunotherapy.This study aimed to construct a prognostic model related to the immune microenvironment of glioblastoma by means of bioinformatics,and to explore the biological functions of genes in this model in glioma.Methods:First,based on the ESTIMATE algorithm,this project divided GBM cases from the Cancer Genome Atlas(TCGA)dataset into high and low immune/stromal score groups,and constructed a tumor microenvironment-related model consisting of four genes.We then selected a C1R gene from this model that has not been extensively studied in glioma for experimental investigation.Using lentivirus-transfected sh RNA,we knock down C1R m RNA in a glioma cell line,and explored the role of C1R in vitro through functional experiments such as proliferation,migration,and invasion.The function of C1R in vivo was explored through intracranial tumorigenesis experiments in nude mice.Based on the transcriptome sequencing of the C1R knocked-dwon cell line and the method of database analysis,we speculated that C1R inhibits glioma cell apoptosis and promotes epithelial-mesenchymal transition through the PI3K-Akt pathway.Through flow cytometry detection of apoptosis,Western blot and other experimental methods,we verified the above speculation.Results : The glioblastoma tumor microenvironment prognostic model constructed by CLECL5 A,SERPING1,CHI3L1 and C1R has a good predictive effect on the short-term and long-term prognosis of glioblastoma.This model is associated with the infiltration of immune cells;it may drive the hypoxic phenotype of necrotic peripheral GBM;it has a good effect on the restratification of IDH wild-type glioblastoma,and can be used to guide the evaluation of clinical treatment.Experimental studies on C1R have demonstrated that C1R is highly expressed in most glioma cell lines compared to normal glial cell line;knockdown of C1R inhibit migration,invasion and promote apoptosis under hypoxia.Although knockdown of C1R has no significant effect on the tumor size in nude mice,it could attenuate invasiveness of tumor in nude mice.Transcriptome sequencing results suggest that knockdown of C1R has significant effects on biological processes such as epithelialmesenchymal transition,apoptosis and PI3K-Akt-motr.Further,Western blot experiments show that,inhibition of C1R expression can up-regulate cleaved caspase-3(cleaved Caspase3),E-cadherin(also known as CDH1)and down-regulate phosphorylated protein kinase B(p-AKT)),human phosphorylated phosphoinositide 3 kinase(p-PI3K),B-cell lymphoma/leukemia-2(Bcl-2),caspase 3(Caspase3),vimentin(Vimtin),matrix metalloproteinase 9(MMP9).Conclusions:1.The glioblastoma tumor microenvironment-related model constructed by CLECL5 A,SERPING1,CHI3L1 and C1R not only has a good prompting effect on the short-term and long-term prognostic of GBM patients,but also can be used as an independent biological prognosis and stratification marker for GBM.2.C1R inhibits glioma cell apoptosis and promotes epithelialmesenchymal transition through PI3K-Akt pathway.