Histone Demethylase KDM3A Promotes The Expression Of Hippo Signaling Pathway Target Genes And The Occurrence Of Colorectal Cancer Through The Enhancer Activation

Cancer has become the first killer of human health,and the number of people who died from cancer every year in the world is constantly on the rise.Hippo signaling pathway is related closely to various cancer occureence and development,and its role in the development of cancer has always been a hot research topic.Hippo signaling pathway activated when cell starved,and the addition of FBS inhibits Hippo pathway activity,also stimulate downstream target genes expression.In this article,in the process of methyltransferase or demethyltransferase si RNA library screening,we found KDM3 A knock-down repressed Hippo pathway downstream genes expression in colorectal cancer cell line HCT116,and analysis of gene expression spectrum further verified this thesis.Then the study of molecular regulatory mechanism found that applied of KDM3 A demethylase dead mutant had no effect on Hippo downstream genes,wheras imposed of H3K9me2 methyltransferase G9 a inhibitors—BIX01294 and UNC0631,rapidly enhanced Hippo target genes expression.These results manifested KDM3 A demethylase activity is indispensable for KDM3 A regulating Hippo pathway.Furthermore,Ch IP experiments reflects KDM3 A regulated Hippo pathway via two patterns,on the one hand,KDM3 A enriched on YAP and regulated the transcription of YAP via influencing YAP genebody H3K9me2 levels.On the other hand,KDM3 A directly binding on target genes of CTGF and CYR61 genebody,affect the H3K9me2 levels both on genebody and genes ehancers.When KDM3 A deleted,H3K9me2 signals increased on enhancers of CTGF and CYR61,maeanwhile significantly impressed enhancer hallmaker H3K27 ac levels and binding of transcriptional factor TEAD1,which declared KDM3 A directly regulates the transcription of Hippo pathwway target genes by influencing enhancers activity and the binding of transcription factors.Futhermore KDM3 A promote cell proliferation,division and migration ability via Hippo signaling pathway,and lack of KDM3 A significantly inhibit the ability of tumor growth in nude mice,which explain KDM3 A as a proto-oncogene involved in the Hippo signaling pathway regulation.Via gene expression and TCGA data analysis,we found that coactivatior YAP and KDM3 A were both high expression and tightly correlated in colorectal cancer tissue.TCGA data revealed high expression of KDM3 A in colorectal cancer tissues probably indicates extraordinarily shorter surviving time of patients,wheras Hippo pathway key node protein YAP and target genes CTGF and CYR61 expression have no difference on colorectal patients.As a result,KDM3 A can be used as a target for medical treatment of colorectal cancer.To sum up,this paper studies the influence of KDM3 A on Hippo pathway by means of biochemistry,cell biology and epigenomics,and explores its implications in human biology.We identify KDM3 A as a potential molecular marker for postoperative survival of colorectal cancer patients,and provide new ideas and theoretical basis for early clinical diagnosis and drug design.