Bioinformatics Analysis Differential Gene Of Non-small Cell Lung Cancer And To Explore Clinical Significance Of MKI67

Objective:Lung cancer is the most malignant tumor with the highest morbidity and mortality rate in the world,it is particularly important to diagnose and evaluate the prognosis of early lung cancer.Through the exploration of lung cancer differentially expressed genes to the occurrence and development of the disease,the treatment of lung cancer has developed from the traditional surgery,radiotherapy and chemotherapy to the comprehensive treatment including targeted therapy and immunotherapy,and the treatment of lung cancer will gradually be individualized and precise.It is important to find the molecular targets of differential genes in lung cancer patients.The purpose of this study was to:1.Analyse the genes differentially expressed between non-small cell lung cancer(NSCLC)and normal lung tissue based on bioinformatics,select the key genes in the occurrence and development of NSCLC,explore the biological functions of differential genes,and evaluate their feasibility as molecular targets in the treatment of lung cancer.2.Verify the role of target gene MKI67 in the occurrence and development of lung cancer,and study its relationship with clinicopathological stage and prognosis of NSCLC patients.The molecular mechanism of the occurrence and development of MKI67 in NSCLC was analyzed,and the value of MKI67 as a biomarker in the diagnosis and prognosis evaluation of NSCLC patients was discussed,the feasibility of the formulation of postoperative adjuvant therapy for patients undergoing adjuvant clinical surgery and the potential of providing new molecular targets for treatment were discussed.Methods:1.Bioinformatics analysis of NSCLC(1)Cluster Analysis and Screening of Differentially Expressed Genes(1)NSCLC gene expression RNASeq dataset was downloaded from The Cancer Genome Atlas database.R(version 4.0.3;http://r-project.org/)and DESEQ2 software packages were used to screen differentially expressed genes(DEGs)between NSCLC and normal lung tissue.(2)From the UCSC Xena(https://xenabrowser.net/hub/)(based on TCGA database)we download NSCLC lung cancer samples of RNA-seq normalized data and clinical pathology data,and WGCNA software package was used to cluster the clinical phenotype related module genes.(2)The module genes obtained from cluster analysis were used to verify the differential genes and perform functional analysis(1)The co-expressed gene networks screened by WGCNA software package were imported into Cytoscape3.7.2,and the key subnetworks were extracted by Cytohubba plug-in.12 algorithms,such as MCC,were used to screen out the hub genes according to their weight.(2)By using funrich3.1.3 software,the mechanism of its occurrence and development was discussed through gene set enrichment analysis(GSEA),Gene Ontology(go),KEGG(Kyoto Encyclopedia of genes and genes)pathway enrichment analysis,and protein protein interaction(PPI).(3)Through the Kaplan-Meier plotter database(https://kmplot.com/analysis/)for survival analysis.2.Expression and clinical significance of MKI67 in NSCLCThrough preliminary bioinformatics analysis,it was clear that the expression of mki67 gene in lung cancer tissues was significantly different from that in normal tissues,and its related gene expression network was obtained.The clinical significance of NSCLC was analyzed by using local clinical data and online database.(1)Relationship between MKI67 and clinicopathologyClinical data of 438 patients admitted to the Department of Thoracic Surgery,China-Japan Union Hospital of Jilin University from March2015 to October 2019 were collected.There were 208 male patients and230 female patients.There were 368 patients in stage I,34 in stage II,31 in stage III,and 2 in IV.There were 364 patients with low Ki67expression(≤50%)and 74 patients with high Ki67 expression(>50%).SPSS software was used to analyze the relationship between high expression of Ki67 and clinicopathological characteristics such as gender,smoking index,tumor maximum diameter,clinical stage,etc.(2)Bioinformatics analysis and verification of MKI67 were carried out using online database(1)The Oncomine database was used to analyze the expression of MKI67 in cancer tissues and paracancerous tissues of NSCLC patients,and in different tumor types.(2)The human protein expression map(HPA)database was used to analyze the biological function,expression level and distribution of MKI67 in human body.(3)Kaplan Meier plotter database was used to online survival analysis,evaluate of MKI67 as the prognosis of NSCLC potential biomarkers,and the clinical value of treatment of target genes.Results:1.Bioinformatics analysis of NSCLC prognostic related genes(1)Screening of differentially expressed genes between NSCLC and normal lung tissueFrom 1146 NSCLC samples in the TCGA database,3631 upregulated genes with NEK2,KIF4 a,CDC20,TYMS,TEK,TOP2 A,EXO1 and 1944 down-regulated genes with TEK,RTKN2,RAMP2,ACVRL1,EMP2,SEMA3 G were screened by difference analysis.CNS and so on were obtained by WGCNA cluster analysis.By WGCNA cluster analysis,the central genes CDCA5,KIF2 C,MYBL2,TPX2,KIF4 A,CDC45,CENPA,DEPDC1,CCNB2 were highly correlated with the surrounding genes.(2)Identification and functional analysis of core genesCytohubba,the plug-in in Cytoscape3.7.2,was used to calculate the network of common differentially expressed genes,and the central genes,including NEK2,KIF4 A,TEK and TOP2 A,were screened by the degree method.They are mainly concentrated in signal communication,cell growth and maintenance,signal transduction and immune response.Moreover,the high expression of most of the core genes indicates a poor clinical prognosis.2.Expression and clinical significance of MKI67 in NSCLC tissuesThrough the above bioinformatic analysis,it was clear that the expression of MKI67 gene in lung cancer tissues was significantly different from that in normal tissues,and its related gene expression network was obtained.Clinical data of local NSCLC patients and online database were used to analyze its clinical significance.(1)The relationship between MKI67 and clinicopathologyThe clinicopathological data of local NSCLC patients were analyzed,and the expression level of MKI67 encoding was correlated with gender(P= 0.000051),pathological stage(P=0.02),maximum tumor diameter(P=0.000156),lymph node metastasis(P=0.024),BMI(P=0.011)of NSCLC patients,but not with distant metastasis(P= 0.165)and smoking index.(2)Bioinformatics analysis and verification of MKI67 were carried out using online database(1)The expression level of MKI67 in human organs was analyzed by using Oncomine database,and the results showed that MKI67 was overexpressed in most human tumors,including lung cancer and bladder cancer,central nervous system cancer,breast cancer,cervical cancer,colorectal cancer,esophageal cancer,gastric cancer,liver cancer,kidney cancer and other malignant tumors.In addition,the expression of MKI67 was also consistently increased in different lung cancer subtypes.(2)Ki67 is a protein encoded by human MKi67 gene,which is expressed in G1,S1,G2 and M phases of the cell cycle,and the monoclonal antibody Ki67 can only recognize nuclear antigen in proliferating cells.Because of this characteristic,it can be used as a cell proliferation marker to objectively measure the proliferation index.It is generally believed that the higher positive rate of Ki67 expression,the greater the proliferation activity.(3)Kaplan Meier plotter database online survival analysis,the results show that the MKI67 high expression of adenocarcinoma patients survival rate significantly decreased,and no obvious correlation with squamous carcinoma patients with long-term survival,as the prognosis of NSCLC potential biomarkers,has a certain clinical value for the treatment of target genes.Conclusion:(1)Based on bioinformatics analysis method,multiple core genes,such as NEK2,KIF4 A,CDC20,TYMS,TEK,TOP2 A,and EXO1,were screened as biomarkers that have predictive effect on NSCLC prognosis and therapeutic potential.(2)The target gene MKI67 is highly expressed in a variety of malignant tumors.Ki67 is a protein encoded by MKI67 gene,which plays an important role in cell cycle and can be used as a biomarker to evaluate cell proliferation.The higher the positive rate of Ki67 expression,the greater the proliferative activity.Mki67 can be used as a potential prognostic biomarker and therapeutic target gene for lung adenocarcinoma.