The Study Of The Expression Of Bit1 In Glioma And Its Impact On The Biological Behavior Of Tumor Cells

BackgroundGlioma is the most common primary intracranial tumor.Due to the high malignant degree of glioma cells,extensive invasive growth and high proliferation characteristics,it is difficult to completely remove the operation and the recurrence rate after operation is extremely high.At present,gliomas are mainly surgically resected and supplemented with comprehensive treatment of radiotherapy and chemotherapy,but the treatment effect is still poor,and the survival rate is still low.Anoikis is closely related to tumor invasion and metastasis,and is the key link of malignant progress of tumor cells.As an effector molecule of anoikis,Bitl(bcl-2 inhibitor of transcription 1)can induce a non-caspase pathway-dependent apoptosis when cells are detached from the surrounding cells or the extracellular matrix.And studies have shown that there are tissue differences in the role of Bitl in different tumor tissues,which can promote or inhibit tumor growth.However,the regulation of Bitl on the malignant biological activity of gliomas has not been reported.The purpose of this study was to investigate the expression of Bitl in gliomas and its effect on the malignant biological activity of tumors through in vivo and in vitro experiments and clinical tissue analysis.ObjectiveTo investigate the expression of Bit1 in glioma tissues and cells,to construct a stable silencing glioma cell line of Bit1,and to test the effects of stable silencing of Bitl on glioma cell proliferation,apoptosis,invasion and migration in vitro And the effects of subcutaneous xenograft tumor proliferation and apoptosis in nude mice in vivo.Methods1.Collect clinical glioma tissues and normal brain tissue samples of different malignant grades,and use fluorescence quantitative PCR and Western blot to detect the expression level of Bit1 in tissue samples,and observe the expression of Bitl in glioma tissue.Express the situation.2.Quantitative quantitative PCR and Western blot were used to detect the expression of Bitl in glioma cell lines U251,U87,SHG44,LN229,A172 and normal brain glial cells HEB.The lentiviral vector was used to introduce the interference plasmid of Bitl into the gel.The glioma cell line U87 cells were screened to establish a stable and silent Bit1 glioma cell line.3.MTT assay,flow cytometry,Transwell invasion and migration experiments were used to detect the changes in the proliferation,apoptosis,invasion and migration ability of Bit1 silent cell lines.4.The subcutaneous tumor formation experiments and TUNEL experiments of nude mice were used to detect the tumorigenic and apoptotic changes of the Bit1 silent cell line in vivo.Results1.The expression levels of Bit1 mRNA and protein in glioma tissues were lower than those in normal control brain tissues,and the expressions of gliomas(WHO grades)increased,the expression decreased significantly,and the difference was statistically significant(P<0.01).2.The expression levels of Bit1 mRNA and protein in different glioma cell lines were lower than those of the normal control glioma cell line HEB,the difference was statistically significant(P<0.05),and was similar to other glioma cell lines.In comparison,Bit1 showed relatively high mRNA and protein expression levels in U87 glioma cell lines.3.In vitro cell experiment:Compared with the negative control group,the cell proliferation,invasion,and migration ability were significantly increased,and the apoptotic capacity was reduced after the expression of Bit1 was silenced(P<0.05).4.In vivo animal experiments:After the expression of Bitl was silenced,the growth of subcutaneously transplanted tumors in nude mice was significantly enhanced,and the apoptotic capacity was reduced.The differences were statistically significant(P<0.05).Conclusions1.Bitl is lowly expressed in glioma tissues and cells,and is closely related to the degree of tumor malignancy.2.The silencing of Bitl enhances the proliferation,invasion and migration ability of glioma cells in vitro,and reduces the apoptosis ability.3.Silence of Bitl expression promotes the growth of subcutaneous xenografts in nude mice in vivo and inhibits their apoptosis.