Molecular Mechanisms Of Downregulation Period2by Lentivirus Enhance Apoptosis Of Glioma U343Cell Irradiated With X-ray

Objective To investigated the mechanism by which downregulated expression of clockgenes Perod2(Per2) promotes apoptosis of glioma cells exposed to X-rays.Method Build and synthetic the Per2-shRNA, Control-shRNA (NC) lentivirus, whichinfected p53wild-type human U343glioma cells to gain the shRNA-Per2cell group with alow expression of Per2and Control cells by selecting with puromycin.Two groups of U343cells were irradiated with6mV100cGy X-ray irradiation, and thenanalyzed the damage of DNA and cells apoptosis by several methods, such as SCGE analysis,Annexin V-FITC/PI flow cytometry, and this study also use the RT-PCR and Western Blot todetect the expression of genes ATM, p53and c-myc which related to DNA repair and cellsapoptosis.Results Per2-shRNA lentivirus could significantly reduced the expression of clockgene Per2in human glioma U343Cells; Compared with the control cell group, cells ofshRNA-Per2group showed a serious DNA damage and apoptosis rate after irradiation by X–ray and in the1h,12h,24h after X-ray, shRNA-Per2cell group showed a increasing trend inDNA damage and apoptosis as well; Moreover, with the decreased expression of Per2protein,the expression levels of ATM and p53were also significantly reduced, while the expressionlevel of c-myc was significantly increased.Conclusion Downregulated expression of clock gene Per2could increase the sensitivityto X-ray of human glioma cell line U343; And as the upstream gene, Per2could weakens theeffect in ATM-p53pathway of damage repair by regulating the expression of ATM, p53and c-myc, then promoted apoptosis of glioma cell U343; This study also provide a reliable basisfor the target gene treatment of glioma in clinical.