Trifluoperazine Prevents FOXO1 Nuclear Excretion And Reverses Doxorubicinresistance In The SHG44/DOX Drug-resistant Glioma Cell Line

Objective: To explore the effects of trifluoperazine(TFP)on increased doxorubicin(DOX)sensitivity through inhibiting nuclear exclusion of Forkhead box O1(FOXO1)and reducing the expression of multidrug resistance genes in glioma SHG44/DOX cell line.Method: The Real-time PCR,western blot and immunofluorescence were used to analyze the levels of FOXO1(nuclear and cytoplasm,respectively),MDR1,MRP1,LRP in SHG44/DOX cells and SHG44 cells.Next,The SHG44/DOX cells were divided into blank group,DOX group and DOX+TFP group.The cell viability,cell cycle and early apoptosis were investigated using CCK-8,flow cytometry and caspase-3 activity assay.Furthermore,the levels of nuclear and cytoplasm FOXO1,multidrug resistance genes and intracellular concentrations of DOX in the three groups were also observed.The subcutaneous xenograft tumors were established by SHG44/DOX.After treatment with DOX alone or DOX+TFP for 7,14,21 and 28 days,the tumor volumes,proliferation indexes and FOXO1 expression were tested.Results: The MDR1,MRP1,LRP and cytoplasm FOXO1 were higher in SHG44/DOX than SHG44.The CCK8,flow cytometry and caspase-3activity assay showed that TFP was able to promote DOX-inducedcytotoxicity,cell cycle arrest at G0/G1 and early apoptosis.In addition,TFP inhibited FOXO1 nuclear exclusion,contributing to downregulation of multidrug resistance genes and increases in intracellular DOX concentrations.In vivo studies demonstrated that DOX+TFP reduced the tumor volumes and proliferation indexes,coupled with higher levels of FOXO1 protein.Conclusion: TFP could decrease the DOX resistance through the stimulation of FOXO1 nuclear translocation and the suppression of multidrug resistance genes in SHG44/DOX,contributing to outstanding clinical prospects for tumor chemotherapy...