FOXO1-miR-506 axis promotes chemosensitivity to temozolomide and suppresses invasiveness in glioblastoma through a feedback loop of FOXO1/miR-506/ETS1/FOXO1 / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

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.

Effects of miR-130b-5p targeting E26 transformation specific-1 on proliferation,migration and invasion of prostatic cancer cells and its mechanism / 中国生物制品学杂志

@#Objective To investigate the effects of miR-130b-5p targeting E26 transformation specific-1(ETS1)on proliferation,migration and invasion of prostatic cancer(PCa)cells and its mechanism. Methods The mRNA transcription level of miR-130b-5p gene in PCa tissues,adjacent tissues,(LNCap,PC-3,DU-145)and normal prostate cells(RPWE-1)PCa cells was measured by qRT-PCR,and the expression of ETS1 protein in PCa cells was detected by Western blot. Bioinformatics,fluorescein experiment,qRT-PCR and Western blot were used to predict and verify the targeting relationship between miR-130b-5p and ETS1. PC-3 cells were divided into control group(without any treatment),mimic group(transfected with miR-130b-5p mimic)and mimic + ETS1 group(transfected with miR-130b-5p mimic + pcDNA-ETS1). The cells were detected for the proliferation and viability by clone formation assay and CCK-8 respectively,measured for the migration and invasion by scratch test and Transwell chamber assay,and detected for the expression of invasion-related proteins and PI3K/AKT/mTOR pathway-related proteins by Western blot. Results The transcription level of miR-130b-5p mRNA in PCa tissues was significantly lower than that in adjacent tissues(t = 12. 450,P < 0. 001);Compared with RPWE-1 cells,the transcription level of miR-130b-5p mRNA in LNCap,PC-3 and DU-145 cells decreased significantly(t = 4. 463,7. 103 and 5. 741,P = 0. 001 2,< 0. 001 and < 0. 001,respectively),while the expression level of ETS1protein increased significantly(t = 4. 850,9. 325 and 7. 723,P = 0. 008,< 0. 001 and = 0. 002,respectively). miR-130-5p targeted and negatively regulated the expression of ETS1. Compared with the control group,the cloning rate,viability and scratch healing rate of cells in mimic group decreased significantly(t = 11. 370,10. 640 and 15. 660,respectively,each P < 0. 001),the number of invasive cells decreased significantly(t = 10. 160,P < 0. 001),the expression levels of matrix metalloproteinase-2(MMP-2),MMP-9 and vimentin decreased significantly(t = 15. 120,9. 992 and 12. 600,P < 0. 001,< 0. 001 and = 0. 002,respectively),while the expression level of E-cadherin increased significantly(t = 6. 928,P < 0. 001),and the phosphorylation levels of phosphatidylinositol-3 kinase(PI3K),protein kinase B(AKT)and mammalian target of rapamycin(mTOR)decreased significantly(t = 7. 746,8. 041 and 11. 510,P = 0. 002,0. 002,and < 0. 001,respectively);Compared with mimic group,the cell cloning rate,viability,scratch healing rate significantly increased in mimic + ETS1 group(t = 6. 988,6. 642 and 6. 660,respectively,each P < 0. 001),the number of invasive cells significantly increased(t = 4. 082,P = 0. 002),the expression levels of MMP-2,MMP-9 and vimentin proteins were significantly up-regulated(t = 10. 410,6. 754 and 8. 521,P = 0. 002,0. 003 and 0. 002,respectively),however,the expression level of E-cadherin was significantly down-regulated(t = 4. 648,P < 0. 01),and the phosphorylation levels of PI3K,AKT and mTOR were significantly up-regulated(t = 4. 850,4. 323 and 10. 840,P = 0. 008,0. 008 and < 0. 001,respectively)Conclusion miR-130b-5p targets ETS1 to inhibit the proliferation,migration and invasion of PC-3 cells,which may be through the regulation of PI3K/AKT/mTOR signaling pathway.