Experimental Study On The Relationship Between The Expression Of MiR-125a-5p And The Transition Of Epithelial Mesenchymal Transition In NSCLC-TKIs

Objective: To investigate whether miR-125a-5p regulate epithelial-mesenchymal transition leading to the resistance of EGFR-TKIs in NSCLC cells.,Methods:The transfected lung adenocarcinoma EGFR-TKIs resistant cell line PC9ER was divided into up-regulation group(PC9ER-miR-125a-5p)and miR-125a-5p down-regulation group(PC9ER-sh RNA-miR-125a-5p)with lentiviral infection.Observa tion of cell and cell migration ability with scratch experiments,Western blot and RT-PCR were used to detect the protein and m RNA expression level of EMT markers(E-cadherin,Vimentin,Zeb1,Snail)in the cell lines above.Results:1.Morphology of cells down-regulated miR-125a-5p were changed to spindle shape,cell scratches were significantly narrowed as well.2.The expression of E-cadherin m RNA in PC9ER cells was lower than that in PC9 cells(P <0.05).Compared with PC9ER cells,the expression of E-cadherin in PC9ER-miR-125a-5p cells was significantly increased(P<0.05).The expression of E-cadh erin in PC9ER-sh RNA-mi R-125 cells was lower than that in PC9ER-miR-125a-5p cells(P=0.03).3.Vimentin m RNA expression level in PC9ER cells was significantly higher than that in PC9ER cells(P=0.03).In PC9ER-miR-125a-5p cells expression was lower than that in PC9ER cells(P=0.03).Down-regulated Vimentin m RNA expression exists in mi R-125 cells when it was ompared with PC9ER-miR-125a-5p cells,(P=0.007).4.Compared with PC9ER-miR-125a-5p cells,m RNA expression of Snail and Zeb1 were significantly increasing in PC9ER-sh RNA-miR-125a-5p cells.(P=0.0071,P=0.023).5.In terms of protein expression level,E-cadherin was up-regulated in PC9 and PC9ER-miR-125a-5p cells,while Vimentin,Snail and Zeb1 were increased in PC9ER and PC9ER-sh RNA-miR-125a-5p cells.Conclusion: MiR-125a-5p may induce changes of EMT in resistant to erlotinib of NSCLC,with the decreased expression of E-cadherin and the increased expression of Vimentin and EMT-related transcription factor Snail and Zeb1.The miR-125a-5p was involved in the regulation of EMT,which may be one of the causes of NSCLC-TKIs resistance.