Bioinformatics-based Analysis And Preliminary Validation Of Tumor Prognostic Markers FOXM1 In Triple-negative Breast Cancer

Objectives: The bioinformatics research was carried out basing on the m RNA sequencing data of triple negative breast cancer(TNBC)in The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)databases;and the transcription factor gene and its biological function in TNBC were further analyzed using the Cistrome Cancer database to discover the key gene related to the occurrence,development and prognosis of TNBC.Furthermore,the function of this key gene in TNBC was verified by the in vitro cell experiments,which may provide potential molecular targets for predicting prognosis and treatment of TNBC in clinic.Methods: 1)TNBC gene expression data and transcription factor dataset were respectively downloaded from TCGA and GEO databases and Cistrome Cancer database,and the differentially expressed genes were obtained through the "lima" R software package,which were then combined to obtain the key genes.Moreover,we construct a prognosis model of TNBC and divide patients into high-risk and low-risk groups based on the median risk level score to compare the survival differences between these two groups.In addition,we use STRING online database and Cytoscape software to build an interaction network to analyze the function of the target gene.2)We used sh RNA plasmid to silence the target expression in TNBC cell line——SUM159 cells,and then detect the cell proliferation,clone formation and migration ability.Furthermore,to explore the key signaling pathways of the target gene in TNBC,total RNA in SUM159 cells was extracted for the RNA seq and bioinformatics analysis.In addition,the h TFtarget database was used to predict differentially expressed transcription factors in TNBC,while the RNA seq results were used to identify potential target genes for the target gene regulation,and q PCR experiments were conducted to validate the relevant genes.Results: Seven differentially expressed transcription factors including KLF4,MYH11,PPARG,MYBL2,EZH2,FOXM1,and EGR1 were screened using TCGA,GSE37751/GSE53752,and Citrome Cancer databases.Meanwhile,prognostic model analysis showed that FOXM1 is closely related to the prognosis of TNBC patients.In addition,in vitro cell experiments confirmed that silencing FOXM1 expression in SUM159 cells can significantly inhibit the proliferation,cloning and cell migration of TNBC;The RNA seq analysis results indicated that FOXM1 may affect TNBC cell cycle and proliferation by regulating downstream protein kinase activity and gene transcription.HTFarget prediction analysis and q PCR experiments have preliminarily confirmed that FOXM1 silencing can significantly downregulate the m RNA levels of IGFBP3,GDF15,and WNT5 B.Therefore,FOXM1 may affect tumor progression of TNBC by regulating the transcription of these three genes.Conclusion: Based on bioinformatics and preliminary experimental verification,this paper identified the key role and mechanism of FOXM1 in TNBC.FOXM1 gene is closely related to the occurrence and development of TNBC,and may become a biomarker and treatment target for TNBC prognosis in the future.FOXM1 inhibitors may be potential therapeutic drugs for TNBC,providing potential clinical diagnosis and treatment options.