The Critical Role Of Epigenetic Factors In Uveal Melanoma Tumorigenesis

Part 1.BAP1 regulates cell cycle progression through E2F1 target genes via H2A monoubiquitination in uveal melanoma cellsObjectiveUveal melanoma(UM)is the most common form of primary intraocular malignancy in adult and has the tendency to metastasize.BAP1 mutations are frequently found in UM and are associated with a poor prognosis.The role of BAP1 in cell cycle regulation is currently a research highlight,but its underlying mechanism is not well understood.In this study,we sought to investigate the the molecular mechanism of BAP 1 in UM progression and cell cycle regulationContent and methods1.The expression of BAP1 and cell cycle proteins was analyzed during cell cycle progression in DTB synchronized cells2.Cell migration and invasion were investigated in BAP1 knockdown UM cells Cell cycle profile was determined in BAP 1-depleted synchronized UM cells using flowcytometry3.The expression of BAP1 downstream gene was measured using RT-PCR and Western blot in BAP1 knockdown UM cells4.ChIP was performed to analyze BAP1 and E2F1/HCF-1 binding to E2F1 responsive promoters and H2AK119ub1 level was investigated after BAP1 silencingConclusion1.Endogenous BAP1 levels remained unchanged during cell cycle progression BAP1 regulates cell cycle progression by affecting E2F1 target gene expression2.Downregulation of BAP 1 inhibited growth and the invasiveness of UM cells3.BAP1 can form protein complexes with E2F1/HCF1 and localizes to E2F1 responsive promoters through HCF-14.BAP1 is crucial for H2A monoubiquitinaton and control gene expression through the modification of histone H2AAchievement1.We demonstrate that BAP1 is indispensible for cell cycle progression,and is especially important for G1/S transition2.We display the function of BAP1 in UM progression and verify the role of BAP 1 in UM migration,invasion and cell cycle regulation3.We identify the epigenetic mechanisms of BAP 1 regulating downstream target genes,in which BAP1 can form protein complexes with E2F1/HCF1 and localizes to E2F1 responsive promoters through HCF-1ObjectiveUveal melanoma(Uveal Melanoma,UM)is the most common primary intraocular malignant tumor in adults with high metastasis and mortality.Previous studies have focused on the gain/loss of chromosomes and gene mutation.However,the role of long non-coding RNAs(LncRNAs)in UM progression is not well understood.Here we sought to identify the role of LncRNA in UM tumorigenesis and explore the epigenetic function and mechanisms of LncRNA in modifying chromatin complexesContent and methods1.Differentially expressed LncRNA in UM was identified though RT-PCR.2.Stable knockdown cell lines,wound healing assay,soft agar assay and xenograft assay were performed to estimate the role of LncRNA on tumorgenesis3.The downstream target genes of LncRNA were identified by cDNA microarray analysis.Transwell migration assay and soft agar assay were performed to demonstrate the functions of target gene in tumor progression4.Chromatin Immunoprecipitation,Chromatin oligonucleotide precipitation were utilized to investigate the underlying epigenetic mechanism of LncRNA in UM progressionConclusion1.P2RX7-V3 is a novel oncoRNA which promotes UM cell migration and tumor formation2.LncRNA-891 is a novel LncRNA which functions as a UM oncoRNA and promotes the proliferation,migration and colony formation of UM cells3.PCDH20 is the target gene of LncRNA-891.LncRNA-891 inhibits PCDH20 transcription and finally promotes tumor progressionAchievement1.We define a novel P2RX7 transcript variant 3 in UM tumorigenesis2.We define a novel UM specific nuclear LncRNA-891,which serves as a tumor oncoRNA3.Our study introduces protocadherin(PCDH20)into the tumor field.