Study On The Mechanism Of MAPK1 In Gastric Cancer Invasion And Metastasis

Background and Objective:The expression of mitogen-activated protein kinase 1(MAPK1)in gastric cancer(GC)tissues is significantly increased and plays an essential regulatory role in the development of GC.It has been reported that MAPK1 can act as a kinase to dephosphorylate,activate related genes and signaling pathways,and act as a transcription factor to directly bind to the gene’s promoter region to regulate gene transcription and affect protein level.Current studies focus on MAPK1 as a kinase that can promote the migration and invasion of GC,but whether MAPK1,as a transcriptional regulator,is involved in tumor metastasis is unclear.Therefore,this study intends to study the transcriptional regulation mechanism of MAPK1 as a transcription factor in GC invasion and metastasis,reveal the new functional mechanism of MAPK1 in cancer,and provide fresh ideas and a theoretical basis for developing combined drugs to inhibit MAPK1 function and treat GC.Methods:(1)We constructed the MAPK1 overexpression AGS cell model.Then the migration and invasion ability of the MAPK1 overexpression,negative control,and control groups were detected by transwell assay.(2)We constructed the MAPK1 knockdown AGS cell model and extracted the m RNA of MAPK1 knockdown group and control group cells for database construction and sequencing,namely RNA-sequencing(RNA-seq).The transcriptional target genes and functional pathways regulated by MAPK1 were analyzed by bioinformatics.(3)AGS cells were cross-linked and lysed,followed by chromatin immunoprecipitation to capture MAPK1-DNA complexes in AGS cells,digestion of proteins,extraction of DNA for library construction and sequencing,namely chromatin immunoprecipitation and highthroughput sequencing(ChIP-seq).The target genes and molecular mechanisms of MAPK1 transcriptional regulation were analyzed by bioinformatics.(4)We integrated the above RNA-seq and ChIP-seq data to reveal the transcriptional regulation mechanism of MAPK1.Results:(1)Compared with the negative control and control groups,the number of AGS cells with migration and invasion in the MAPK1 overexpression group significantly increased.(2)We analyzed the RNA-seq data and obtained 111 differentially expressed genes(DEGs)after MAPK1 knockdown,of which 80 genes were significantly reduced.These 80 genes were mainly involved in biological processes such as apoptosis,positive regulation of cell proliferation,and gene expression.(3)We analyzed ChIP-seq data and identified 92898 MAPK1 binding peaks and 6493MAPK1 binding genes.MAPK1 was significantly enriched near the genes’ transcription start site(TSS).(4)This study obtained 8 MAPK1 target genes by overlapping RNA-seq and ChIP-seq data.The expression levels of KRT13,KRT6 A,KRT81,MYH15,STARD4,SYTL4,and TMEM267 decreased significantly after MAPK1 knockdown,and the expression of FGG increased significantly after MAPK1 knockdown.Three genes(KRT81,KRT6 A,and KRT13)were associated with cancer metastasis and migration.Our data showed that MAPK1 could bind to the promoter regions of KRT81,KRT6 A,and KRT13,and MAPK1 knockdown significantly reduced the expression levels of these three genes.Conclusion:(1)MAPK1 promotes GC migration and invasion.(2)MAPK1 can widely interact with genes by binding to the gene’s promoter region as a bidirectional transcription factor.(3)MAPK1 may up-regulate the expression of KRT81,KRT6 A,and KRT13 by binding to their promoter regions,thereby promoting GC migration and invasion.