Research On The Acquired EGFR-TKIs Regulation Of Durg Resistance Function Of Notch1 In NSCLC-EMT

Objective: To investigate the mechanism that Notch 1 may induce the acquired resistance of EGFR-TKIs in the epithelial-mesenchymal transformation(EMT)of the non-small lung cancer cells(NSCLC).Methods: Using immunohistochemistry to detect the protein expression of E-cadhenrin,Vimentin,Notch1 in the non-small lung cancer tissue and paracancer tissue.The cell experiments were divided into six groups: Control,Mock,N1ICD,Gefitinib,N1ICD+Gefitinib,N1ICD-sh RNA.Using Lentiviral Vector LV-N1ICD to infect the PC9 cells to up-regulate Notch1 signaling pathway,lentiviral vector LV-N1ICD-sh RNA to infect the PC9 cells to inhibit Notch1 signaling pathway,After72 hours,detected the cell viability by CCK-8.Detected the cell proliferation and migration by wound healing test,cell apoptosis by flow cytometric analysis.Using Western-blotting to detect the protein expression of E-cadhenrin,Vimentin,Notch1,Slug.Using immunohistochemistry to detect the protein expression of Slug in the non-small lung cancer tissue and paracancer tissue,according to the results of Western-blotting.Results: The results of immunohistochemistry in the non-small lung cancer tissue,the protein expression of Vimentin and Notch1 were up-regulated,the protein expression of E-cadhenrin was down-regulated.While in the paracancer tissue,the protein expression of Vimentin and Notch1 were down-regulated,the protein expression of E-cadhenrin was up-regulated.In the cell experiments,the cell viability was increased significantly in the N1 ICD group.Wound healing test showed that N1 ICD group was the migration significantly.In the N1 ICD group,the cell apoptosis of PC9 cells was significantly decreased.The results of Western-blotting in the N1 ICD group,the protein expression of E-cadhenrin was down-regulated,while the protein expression of Vimentin,Notch1 and Slug were up-regulated.According to theresults of Western blotting,the results of immunohistochemistry in the non-small lung cancer tissue,the protein expression of Slug were up-regulated.Conclusion: Over expression of Notch1 will increase the resistance of the non-small lung cancer cells to EGFR-TKIs,while down-regulated the expression of Notch1 will decrease the resistance of the non-small lung cancer cells to EGFR-TKIs.The resistance of the non-small lung cancer cells to EGFR-TKIs may be related to the protein expression of slug.