Effects Of Acute Hypoxic U251 Cells From Nanosilver And The Study Of Radiotherapy Sensitization And Autophagy

As an antitumor agent,AgNPs can be widely used in oncotherapy.There are hypoxic cells in most tumors which resistance to radiation and has poor treatment.Hypoxic is inevitable in human glioma.In previous studies,the radiosensitivity of silver nanoparticles(AgNPs)on human glioma cell in vitro has been demonstrated.However,the influences of AgNPs on hypoxic glioma cell are still unclear.In our study,we discussed the effects of AgNPs in hypoxic glioma U251 cell.Firstly,U251 cells were cultured under normoxic and hypoxic conditions,then,we detected the cytotoxicity of AgNPs to human glioma cells by Cell Counting Kit-8 assay.U251 cells were divided into control group,radiation alone group,silver nanoparticles alone group and combined treatment group,and the apoptosis,colony formation,autophagy,reactive oxygen species(ROS)and mitochondrial membrane potential in each group were determined with flow cytometry.Results show that:1.There was a toxic effect on the AgNP-treated hypoxia glioma cells.For the consideration of cell viability,15 ?g/mL was selected for further study.2.AgNPs enhanced acute hypoxia cells sensitivity to radiation and we found the best ray strength for treatment of acute hypoxia U251 cells.3.We used 3-MA to verify that acute hypoxic U251 cell autophagy could be induced by AgNPs or radiation,and which autophagy was inhibiting cell survival.4.AgNPs exposure led to the production of reactive oxygen species,the loss of mitochondrial membrane potential,and increased apoptosis in hypoxic condition.All the results indicated that silver nanoparticles could efficiently increased radiotherapy sensitization effect of hypoxic glioma and would had theoretical significance to study the increaseing of autophagy and its mechanism,which could provide the basis for the application of nano silver in the field of tumor radiotherapy.