Study On The Mechanism Of Quercetin On Lung Squamous Cell Carcinoma Based On Protein-protein Interaction Network

Objective:In order to analyze the potential molecular targets of Quercetin(QR)in the intervention of Lung squamous cell carcinoma(LUSC),this study used the methods of bioinformatics and network pharmacology,and explored its efficacy in vitro,to explore the mechanism of quercetin in the treatment of lung squamous cell carcinoma,and to provide theoretical reference for future clinical application.Methods:1.Analyze the molecules and targets of LUSC by bio-informatics:First,the relevant data were downloaded from TCGA database,and then the data of lung squamous cell carcinoma were processed by matrix transformation.The lemma software package is used to analyze and screen for differentially expressed genes,the GO/KEGG database is used for path enrichment analysis of genes,and the STRING web site is used to construct the protein interaction network of differentially expressed genes,the candidate target genes of lung squamous cell carcinoma were obtained by topological analysis,and the prognosis of the candidate genes was analyzed.Finally,the key target genes were selected for further analysis by molecular docking.2.Explore the effect of QR on the phenotype of LUSC cell lines:MTT assay was used to detect the effect of quercetin on the proliferation of lung squamous carcinoma cell lines NCL-H520 and NCL-H226.Effects of quercetin on migration of NCL-H520 and NCL-H226 cell lines by scratch test.Flow cytometry was used to assess the effects of quercetin at different concentrations on cell cycle of lung squamous cell carcinoma cell lines.3.Explore the effect of QR on key genes of LUSC: to detect the effect of quercetin in different concentrations on the protein expression level of key target genes of NCL-H520 and NCL-H226 cell lines by western blotting.Results:1.Quercetin can inhibit the proliferation and migration of LUSC cell lines.The MTT assay showed that the inhibitory effect of quercetin on the proliferation of tumor cells increased with the time of quercetin treatment,the cell migration rate of quercetin treated group was significantly different from that of control group(*P < 0.05),and the cell cycle was measured by flow cytometry,the cell cycle of the treated group was arrested at G2/M phase,indicating that quercetin could block the cell cycle progression of lung squamous cell carcinoma.2.Download the tumor tissue data and adjacent tissue data of LUSC through TCGA database,and obtain 2150 differentially expressed genes after differential analysis.Subsequent topological analysis showed that CDC20、KIF4A、EXO1、CENPF、SPAG5、CDCA8、KIF15、ASPM、PLK1、CENPA、MKI67、BUB1B、TTK、DTL、AURKA、NCAPH、MCM10、CENPE、CDCA5、and CENPU were 20 key genes in the differentially expressed gene network.their survival analysis showed that their prognosis analysis was statistically significant.Further enrichment analysis of the GO and KEGG pathways revealed that the differentially expressed genes were mainly located in the cell cycle pathway.Using molecular docking software to perform Molecular dynamics based molecular docking,we selected the high scoring PLK1 gene for further molecular experimental studies.3.Western blot was used to investigate the effects of quercetin on the expression of key proteins,compared with the control group,after 24 h of quercetin(60,120μM)intervention,the expression level of PLK1 protein decreased with the increase of quercetin concentration,P<0.05,The differences were statistically significant.Conclusion:1.QR can inhibit the proliferation and migration of human lung squamous cell carcinoma cells in vitro.2.QR can affect the cell cycle of lung squamous cell carcinoma,and its mechanism is related to down regulating the expression of PLK1 protein.