The Epigenetic Mechanism Of Intraocular Tumor

Objectives Intraocular malignant tumor is a kind of malignant disease which can both lead to blindness and death.Its visual prognosis is poor and may seriously threat the life and life quality of the patients.During the previous studies,researchers focused on studying the genetic mechanism of the intraocular malignant tumor.Recently,the importance of epigenetics has been taken seriously.Many new epigenetic modifications such as chromatin remodeling,long noncoding RNA and new type of histone modifications have been found.And they are potential predisposing factors.This study aims to use new technologies and methods such as chromosome conformation capture,decoy recombinant proteins,and orthotopic transplantation to sudy the mechanism of intraocular tumor.And try to find out the epigenetic therapy to cure intraocular tumor.This study may provide new targets and theoretical basis for the treatment of intraocular tumor.Materials and methods 1.The abnormal chromosome conformation in intraocular tumor was explored by the method of chromosome conformation capture;The target of long noncoding RNA ROR was screened by c DNA microarray;The analysis of abnormal chromosome conformation and regulatory mechanism of long noncoding RNA was carried out by chromatin immunoprecipitation method.2.The function of the abnormal chromosome conformation and the target gene was detected by CCK8 experiment,scratch test,transwell experiment and soft agar experiment.3.The epigenetic therapy for curing intraocular tumor was explored through crotonic acid sodium,small molecule inhibitors and decoy CTCF recombinant protein.4.The expression level of key factors and the therapeutic effect of epigenetic therapy above was verified by immunohistochemistry and mouse xenograft model.Results1.The abnormal conformation mediated by CTCF exists in RB1 promoter region in retinoblastoma.The abnormal conformation can recruit EZH2 to improve the H3K27me3 modification in the RB1 promoter region.It leads to the inhibition of RB1.Knocking down CTCF or using small molecule inhibitor GSK503 can destroy the abnormal conformation.It can activate the expression of RB1,and thereby inhibiting the proliferation ability of retinoblastoma.2.Decoy CTCF recombinant protein can significantly inhibit the proliferation and migration ability of uveal melanoma.Its target SELL is a proto-oncogene.SELL can improve the development of uveal melanoma.3.PRKD3 is the target of lnc RNA ROR.The inhibition of PRKD3 expression can significantly inhibit the proliferation and migration ability of tumors.Lnc RNA ROR can activate PRKD3 expression by removing the trimethylation of H3K27 of its promoter region.4.Crotonic acid sodium can improve the crotonic acylation modification level of histones.And it can inhibit the proliferation and migration ability of uveal melanoma.The crotonic acylation modification level of melanoma is associated with the tumor location and the malignant degree.Conclusions 1.The tumor-suppressor gene inactivation in retinoblastoma was caused by CTCF mediated abnormal conformation.Knocking down CTCF expression or using small molecule inhibitor GSK503 can effectively destroy the abnormal conformation.The reactivation of tumor suppressor gene expression can inhibit the proliferation ability of retinoblastoma.2.Decoy CTCF recombinant protein can significantly inhibit the proliferation and migration ability of uveal melanoma without affecting normal cells.It is a potential multitargeted drug therapy.3.PRKD3 is the target of lnc RNA ROR.Lnc RNA ROR can promotes the proliferation and migration ability of tumors by activating PRKD3 expression.4.Crotonic acid sodium could significantly inhibit the proliferation and migration ability of uveal melanoma.And it does not affect the normal cells.It is a potential small molecule compounds for curing uveal melanoma.