Effects Of Human Epiregulin On Malignant Biological Behavior Of Glioma

Glioblastoma is the most malignant tumor in glioma cells.It is a great challenge for neurosurgeons to cure glioblastoma.Glioblastoma grows rapidly,is easy to metastasize,and is extremely invasive.The prognosis of patients is poor,and the survival rate of patients is still low even after surgery,radiotherapy,chemotherapy and drug-assisted therapy.In recent years,many studies have focused on molecular differences between tumors.Currently,multiple gene mutations such as EGFR,IDH1,MGMT and 1P19 Q have been widely reported in glioblastoma,but the comprehensive molecular mechanism of initiation and metastasis of glioblastoma is still unclear.In order to find more genes related to the occurrence and development of glioblastoma,a gene promoting the migration,invasion and proliferation of glioblastoma epiregulin was found by combining bioinformatics analysis and in vitro molecular biology experiments.EREG is a member of the EGF family.EREG can bind to EGF receptors Erb B1 and Erb B4,stimulate signal transduction of Erb B2 and Erb B3 through ligand-induced homologous receptor isomerization,and activate MEK/ ERK-related signaling pathways.Ultimately,it affects the proliferation,invasion,metastasis,cardiovascular generation,apoptosis inhibition and other cellular processes of tumor cells,endowing tumor invasion ability.Therefore,EREG/Erb B signaling pathway has become a potential target for the treatment and intervention of various cancers.In this paper,transcriptome data of glioma patients were firstly analyzed from a public database--TCGA database,which is a transcriptome database covering different types of tumor,including glioma.The downloaded data will be preliminarily sorted out with Perl software,and the "edge R" package in R software was used for data difference analysis,and the expression of EREG in LGG and GBM samples was compared.Kaplan-meier analysis was further used to evaluate the relationship between EREG expression difference and prognosis in patients with glioma combined with clinical data.In order to reveal the role of EREG in glioma,er EG-related genes were screened out through correlation analysis between the difference genes in the previous analysis results and EREG gene.Then,the online analysis website DAVID was used to conduct GO enrichment analysis on these genes,so as to understand the possible biological functions of EREG from different aspects.And KEGG pathway enrichment analysis to better understand the biological characteristics of EREG.Then,EREG overexpressed cell lines and EREG knockout cell lines were constructed,and the overexpression efficiency and knockout efficiency of EREG overexpressed cell lines and EREG knockout cell lines were verified by q-PCR and WB.Then the migration,invasion,proliferation and apoptosis of glioblastoma in the two cell lines were compared.Meanwhile,the receptors that may be activated by EREG as well as the signaling pathways and target genes that will be activated after EREG overexpression are also found through WB.The results showed that there were differences in the expression of EREG in LGG and GBM samples,In addition,when EREG is highly expressed,the survival rate of patients is often much lower,and conversely,the survival rate of patients is higher.Subsequent GO enrichment analysis and KEGG pathway enrichment analysis indicated that EREG may affect the metastasis of tumor cells.Followed by in vitro experiments also prove that,when overexpression EREG glioblastoma U251 migration ability,attack ability and markedly enhance its capability of proliferation,and knock out after EREG,glioblastoma U87 migration,invasion and proliferation significantly reduced,but also observed the EREG apoptosis of glioblastoma will impact.Overexpression of EREG inhibited the apoptosis of glioblastoma U251,while deletion of EREG promoted the apoptosis of glioblastoma U87.To investigate whether EREG can activate EGFR receptors,cells treated with the eg FR-specific inhibitor erlotinib were found to activate EGFR receptors.The results showed that overexpression of EREG could activate the phosphorylation of AKT and up-regulate the expression of VIM.In conclusion,the study in this paper proved that EREG expression in high-grade gliomas is higher than that in low-grade gliomas,and patients with high EREG expression have a low survival rate.It is speculated that EREG may up-regulate the expression of VIM by activating EGFR receptor and activating AKT pathway,thus enhancing the ability of tumor cells to migrate and invade.Our study sheds light on the regulatory mechanism of glioblastoma migration and invasion,which may contribute to the development of a therapeutic strategy to inhibit glioma metastasis in the future.