Effect Of Wip1 Gene Silencing On Radiosensitivity Of Human Glioma Cells

BackgroundGlioma is the most common malignant tumor in the central nervous system,accounting for about 50%of the primary brain tumors.Glioma is highly malignant,prone to recurrence,high disability,poor prognosis.The most commonly used treatment is surgery combined with radiotherapy and chemotherapy.The continuous progress of chemoradiotherapy,molecular biology and tumor immunology have improved the survival time and quality of life of patients.However,due to the uncertainty of the etiology of glioma,there is a lack of effective means to cure glioma.The overall therapeutic effect of glioma is still unsatisfactory.Some studies have found that resistance to radiotherapy and chemotherapy of glioma is an important reason for its poor therapeutic effect.The sensitivity of treatment mainly depends on cell cycle regulation and self-repair ability of DNA damage.Wipl is a novel proto-oncogene located in the 17q23/q24 region of human chromosomes.It is a negative regulator of the tumor suppressor gene p53.A member of the serine/threonine protein phosphatase(PP2C)family,Wipl gene has been found to be selectively overexpressed in gliomas.The overexpression of Wipl gene can promote the dephosphorylation of Chk1/Chk2MAPK-p53,leading to the carcinogenesis of glioma cells.It has been found that the overexpression of Wip1 gene can promote the dephosphorylation of Chk1/Chk2MAPK-p53,which leads to the carcinogenesis of glioma cells.Hk2 inhibitor alone or in combination can selectively sensitize glioma stem cells to ionizing radiation and TMZ.A series of genes associated with major signaling pathways in autophagy and angiogenesis that,in turn,regulate the cellular response to radiation through a negative feedback mechanism.Silencing WIP1 gene may promote apoptosis by inhibiting the expression of Chkl and Chk2 and enhancing the radiotherapeutic effect of glioma.Therefore,to explore the molecular biological effects and mechanism of Wip1 gene silencing combined with radiotherapy on apoptosis and radiosensitivity of glioma cells.This study was designed to investigate the effect of Wip1 gene on apoptosis of glioma cells by constructing a silencing Wip1 gene model of glioma cells and combining with radiotherapy.And the molecular biological mechanism of the effect on the radiosensitivity of gliomas.Further,to explore a new therapeutic approach for improving the therapeutic effect of glioma.Objectives1.To study the effect of Wip1 gene silencing combined with radiotherapy on apoptosis of U251 glioma cell line Wip1 gene silencing.2.The changes of PChk1/2 protein and mRNA expression in U-251 glioma cells were detected by silencing Wip1 gene combined with radiotherapy to study the mechanism of apoptosis and radiosensitivity of glioma cells induced by silencing Wip1 gene combined with radiotherapy.Methods1.The stable transfected Wip1 gene silencing cell line was constructed by lentivirus transfection into U251 glioma cell line and combined with radiotherapy.2.The percentage of apoptosis was detected by flow cytometry.3.Western Blot and real-time quantitative PCR were used to detect the expression of PChk1/2 protein and mRNA.Results1.The percentage of apoptosis in IR Wip1-group was significantly higher than that in other groups.2.The expression of PChk1/2 protein in IR Wip1-group was significantly higher than that in other groups.Conclution1.Silencing Wip1 gene combined with radiotherapy can increase the proportion of apoptosis and promote the apoptosis of glioma cells.2.Silencing Wip1 gene combined with radiotherapy can decrease the dephosphorylation of Chk1/2,increase the expression of PChk1/2,inhibit the repair ability of DNA damage and enhance the radiosensitivity.