Transcription Factor EN1 Promotes Prostate Cancer Invasion Via Modulation The TR4/EZH2

Background and purposeProstate cancer is one of the most common malignant tumors in urology.In European and American countries,the incidence of prostate cancer ranks first among male malignant tumors,and the mortality rate is second only to lung cancer.In China,the incidence of prostate cancer is increasing year by year.Prostate cancer patients had no obvious symptoms in the early stage.Nearly half of the patients had distant metastasis when they were first diagnosed and lost the chance of radical operation.At present,androgen deprivation therapy is the first choice for metastatic prostate cancer,but most of the patients converted to metastatic castration-resistant prostate cancer about 2 years after androgen deprivation treatment.However,the effective treatment for metastatic castration-resistant prostate cancer is limited and the prognosis of patients is poor.It has become a difficult problem in clinical treatment.Therefore,it is a hotspot to study the molecular mechanism of prostate cancer metastasis and find new molecular markers or therapeutic targets.These achievements will also strengthen and promote the resolution of clinical problems.We want to explore the key target genes of EN1 regulation in metastatic prostate cancer cells,construct the regulatory network of EN1 gene expression,and elucidate its molecular mechanism through the existing molecular biological research methods.To provide new ideas for clinical treatment of metastatic prostate cancer.Methods1.We analyzed the expression level of EN1 in metastatic prostate cancer and compared the difference of EN1 expression between metastatic prostate cancer and localized prostate cancer.Two prostate cancer sample banks were from Memorial Sloan-Kettering Cancer Center(MSKCC)and University of Pittsburgh.2.The effects of different expression of EN1 on migration and invasion of C4-2 and PC3 cells were observed by cell invasion experiment and matrix gel 3D culture experiment.The effect of differential expression of EN1 on metastasis of prostate cancer cells was studied by orthotopic transplantation tumor animal model experiment.3.Combining the data of GSEA database and JASPAR database,we searched for specific sites and possible genes that could bind to transcription factor EN1.The relationship between them was verified by double luciferase reporter gene system.4.The correlation between EN1 and activation of NF-kappa B signaling pathway in clinical TCGA database was analyzed by GSEA bioinformatics enrichment.We explored whether EN1 activates NF-kappa B signaling pathway through TR4/EZH2 or other factors,and studied the correlation between differential expression of EN1 and activation of NF-kappa B signaling pathway in prostate cancer cell line.Results1.The expression of EN1 in mPCa is higher than that in adjacent tissues and localized prostate cancer.2.Knocking down transcription factor EN1 can inhibit the metastasis of prostate cancer cells.Animal experiments showed that knocking down transcription factor EN1 could inhibit the metastasis of PC3 cells in vivo.3.The expression of EN1 and TR4 is positively correlated in prostate cancer.TR4 binds to the promoter region of EZH2 and promotes the invasion and migration of mPCa cells.4.By analyzing the expression profiles of prostate cancer samples in TCGA database,we found that the up-regulation of EN1 expression was significantly correlated with the activation of NF-kappa B signaling pathway.ConclusionTranscription factor EN1 may regulate TR4/EZH2 by transcription,then mediate activation of NF-kappa B signaling pathway and induce metastasis of prostate cancer cells.