To explore the role of forkhead box protein O1(FOXO1)in the progression of glioblastoma multiforme(GBM)and related drug resistance,we deciphered the roles of FOXO1 and miR-506 in proliferation,apoptosis,migration,inva...To explore the role of forkhead box protein O1(FOXO1)in the progression of glioblastoma multiforme(GBM)and related drug resistance,we deciphered the roles of FOXO1 and miR-506 in proliferation,apoptosis,migration,invasion,autophagy,and temozolomide(TMZ)sensitivity in the U251 cell line using in vitro and in vivo experiments.Cell viability was tested by a cell counting kit-8(CCK8)kit;migration and invasion were checked by the scratching assay;apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling(TUNEL)staining and flow cytometry.The construction of plasmids and dual-luciferase reporter experiment were carried out to find the interaction site between FOXO1 and miR-506.Immunohistochemistry was done to check the protein level in tumors after the in vivo experiment.We found that the FOXO1-miR-506 axis suppresses GBM cell invasion and migration and promotes GBM chemosensitivity to TMZ,which was mediated by autophagy.FOXO1 upregulates miR-506 by binding to its promoter to enhance transcriptional activation.MiR-506 could downregulate E26 transformation-specific 1(ETS1)expression by targeting its 3'-untranslated region(UTR).Interestingly,ETS1 promoted FOXO1 translocation from the nucleus to the cytosol and further suppressed the FOXO1-miR-506 axis in GBM cells.Consistently,both miR-506 inhibition and ETS1 overexpression could rescue FOXO1 overactivation-mediated TMZ chemosensitivity in mouse models.Our study demonstrated a negative feedback loop of FOXO1/miR-506/ETS1/FOXO1 in GBM in regulating invasiveness and chemosensitivity.Thus,the above axis might be a promising therapeutic target for GBM.展开更多
基金supported by the National Natural Science Foundation of China(Nos.81402076,81872072,and 82073274)the Science Technology Commission of Shanghai Municipality(No.20S11900700)。
文摘To explore the role of forkhead box protein O1(FOXO1)in the progression of glioblastoma multiforme(GBM)and related drug resistance,we deciphered the roles of FOXO1 and miR-506 in proliferation,apoptosis,migration,invasion,autophagy,and temozolomide(TMZ)sensitivity in the U251 cell line using in vitro and in vivo experiments.Cell viability was tested by a cell counting kit-8(CCK8)kit;migration and invasion were checked by the scratching assay;apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling(TUNEL)staining and flow cytometry.The construction of plasmids and dual-luciferase reporter experiment were carried out to find the interaction site between FOXO1 and miR-506.Immunohistochemistry was done to check the protein level in tumors after the in vivo experiment.We found that the FOXO1-miR-506 axis suppresses GBM cell invasion and migration and promotes GBM chemosensitivity to TMZ,which was mediated by autophagy.FOXO1 upregulates miR-506 by binding to its promoter to enhance transcriptional activation.MiR-506 could downregulate E26 transformation-specific 1(ETS1)expression by targeting its 3'-untranslated region(UTR).Interestingly,ETS1 promoted FOXO1 translocation from the nucleus to the cytosol and further suppressed the FOXO1-miR-506 axis in GBM cells.Consistently,both miR-506 inhibition and ETS1 overexpression could rescue FOXO1 overactivation-mediated TMZ chemosensitivity in mouse models.Our study demonstrated a negative feedback loop of FOXO1/miR-506/ETS1/FOXO1 in GBM in regulating invasiveness and chemosensitivity.Thus,the above axis might be a promising therapeutic target for GBM.
