Objective To investigate the mechanism mediating the regulatory effect of lncRNA MAGI2-AS3 on cisplatin(DDP)resistance in non-small cell lung cancer(NSCLC).Methods MAGI2-AS3 and miR-1269a expression levels were detected by qRT-PCR in DDP-sensitive lung cancer cell lines(A549 and H1299)and their resistant counterparts(A549/DDP and H1299/DDP).In A549 and H1299 cells with MAGI2-AS3 silencing and A549/DDP and H1299/DDP cells overexpressing MAGI2-AS3,the effects of 20 μmol/L DDP on cell viability and apoptosis were examined with CCK-8 assay,colony formation assay,flow cytometry and Western blotting,and the changes in epithelial-mesenchymal transition(EMT)were assessed with wound healing and Transwell assays.The interaction between MAGI2-AS3,miR-1269a and PTEN was predicted using GEPIA,StarBase and miRDB and verified with luciferase reporter gene assay and radioimmunoprecipitation(RIP)assay.A miR-1269a mimic and pcDNA3.1-PTEN plasmid were used to perform the rescue assay.Results MAGI2-AS3 expression was significantly downregulated in lung cancer tissues(P<0.05)in association with a poor prognosis(P<0.05).In the two DDP-resistant lung cancer cell lines,MAGI2-AS3 expression was significantly lowered as compared with the sensitive cells.Silencing MAGI2-AS3 significantly enhanced cell viability and promoted EMT of A549 and H1299 cells irrespective of DDP treatment,and also decreased DDP-induced apoptosis of the cells.In A549/DDP and H1299/DDP cells,MAGI2-AS3 overexpression strongly repressed cell viability and EMT irrespective of DDP treatment and promoted DDP-induced cell apoptosis.Luciferase reporter gene and RIP assays confirmed the binding of MAGI2-AS3 with miR-1269a and the binding of miR-1269a with 3'-UTR domain of PTEN.The rescue assay demonstrated that MAGI2-AS3 acted as a sponge for miR-1269a to promote PTEN expression and downregulate AKT phosphorylation,thus inhibiting EMT and promoting DDP-induced apoptosis of A549/DDP cells.Conclusion MAGI2-AS3 enhances DDP sensitivity of NSCLC by targeted regulation of the miR-1269a/PTEN/AKT signaling axis.
关键词
LncRNA/MAGI2-AS3/miR-1269a/非小细胞肺癌/顺铂耐药
Key words
long noncoding RNA MAGI2-AS3/miR-1269a/non-small cell lung cancer/cisplatin resistance