Effect Of YB-1 Downregulation Via RNAi On EGFR Expression And Cell Proliferation In Human Lung Adenocarcinoma Cell Line A549

Objective:In recent years, Lung adenocarcinoma gradually replaced the squamous cancer as the main pathological types of lung cancer. The surgery and traditional chemotherapy has reliable therapeutic efficacy, but its benefits has been into the relatively stable platform, the targeted therapy and new molecular targeted drugs bring good prospects for anti-cancer research.Human YB-1(Y box-binding protein-1) is an important transcription and translation factor which specific binds to the target gene promoter and enhancer with the Y-box sequences. Epidermal growth factor receptor (EGFR) promoter region contains the Y-box sequence. Both of them play an important role in the tumor priming, proliferation, invasion and metastasis.Based on the above knowledge, we plan to use RNA interference, silence YB-1 protein expression in lung adenocarcinoma cell line A549, investigate EGFR expression differentiation and cell proliferation, initially identify YB-1 protein on the regulation of EGFR expression and cell proliferation.Methods:We used the transfection reagent Lipofectamine2000 and transfected YB-1 siRNA duplex into A549 lung adenocarcinoma cells, then the normal group, Lipofectamine2000 group, Control siRNA group as control. While ensuring the selected YB-1 siRNA duplex with the exact interference results, using RT-PCR, Western Blot analysis of YB-1 and EGFR gene and protein in each group in A549 cell line and MTT assay YB-1 siRNA inhibition rate.The experimental data analyzes by SPSS11.5 statistical software. All experiments will be repeated three times, the measurement data represents by mean±standard error (x±S), using the single factor variance analysis tests whether the differences between experimental groups is significant (P<0.05).Results:1. RT-PCR and Western Blot showed that after YB-1 siRNA interference YB-1 mRNA and protein expression significantly declined, EGFR mRNA and protein expression also decreased (P<0.05), initially confirmed that YB-1 can regulate the expression of EGFR in A549 cell line.2. MTT test showed that YB-1 siRNA interference inhibits cell proliferation after a certain dose (0.0625μl, P>0.05; 0.125μl, P<0.05) and the inhibition has a optimum dose.Conclusion:1. RT-PCR and Western Blot initial testified that YB-1 regulates the expression of EGFR.2. MTT test confirmed that YB-1 siRNA interference can inhibit tumor cell proliferation and the inhibition effect has a optimum dose.