The Function And Molecular Mechanism Of LncRNA-MEG3 In Retinoblastoma

1.The expression of lncRNA-MEG3 in retinoblastoma tissues and cellsObjective:To detecte the expression of IncRNA-MEG3 in retinoblastoma tissues and cells.Methods:The expression of IncRNA-MEG3 were detected with qRT-PCR in 21 cases of retinoblastoma tissues with their corresponding adjacent retina nontumor tissues,retinoblastoma cells(Weri-Rb1 Y79)with normal retinal pigment epithelial cells(hTERTRPE-1).Results:The expression levels of IncRNA-MEG3 in retinoblastoma tissues were significantly lower than their corresponding adjacent retina nontumor tissues.The expression levels of IncRNA-MEG3 in Weri-Rbl and Y79 cells were significantly lower than hTERT RPE-1 cells.Conclusion:LncRNA-MEG3 is hypoexpression in retinoblastoma tissues and cells.2.The effects of lncRNA-MEG3 on proliferation and apoptosis of retinoblastoma cells.Objective:To detect the proliferation and apoptosis of cells after the expression of IncRNA-MEG3 in retinoblastoma cells(Weri-Rbl,Y79)were changed.Methods:Weri-Rbl or Y79 cells was transfected with pcDNA-MEG3 or siRNA-MEG3,and then the proliferation and apoptosis of cells were detected by CCK-8 assay and flow cytometry.Results:The proliferation of Weri-Rbl cells transfected with pcDNA-MEG3 was significantly decreased,and the early apoptosis rate was significantly increasd.The proliferation of Y79 cells transfected with si-MEG3 was significantly increasd expressed and the early apoptosis rate were significantly decreased.Conclusion:LncRNA-MEG3 could inhibit the proliferation viability and promote the apoptosis viability of retinoblastoma cells.3.The effect of DNA methylation on expression of lncRNA-MEG3 and proliferation and apoptosis of retinoblastoma cells.Objective:To explore whether MEG3 gene promoter methylation was one of the reasons for MEG3 gene hypoexpression in Weri-Rbl and Y79 cells and its relationship with IncRNA-MEG3 expression and cell function.Methods:MEG3 gene promoter DNA methylation was detected with Methylation Specific PCR(MS-PCR)in 21 cases of retinoblastoma tissues with their corresponding adjacent retina nontumor tissues,Weri-Rbl.Y79 cells to find out the relationship between MEG3 gene promoter DNA methylation and the expression of IncRNA-MEG3.5-Aza-CdR was used to reduce MEG3 gene promoter DNA methylation of Weri-Rbl and Y79 cells,and then the IncRNA-MEG3 expression and the cell proliferation,apoptosis were detected.5-Aza-CdR and siRNA-MEG3 were both used as the experimental group,CCK-8 test and flow cytometry were performed to detect the proliferation and apoptosis of cells.Results:The MEG3 gene promoter DNA methylation in retinoblastoma tissues was significantly higher than their corresponding adjacent retina nontumor tissues,and the expression of IncRNA-MEG3 was significantly reduced in the methylation group.The MEG3 gene promoter DNA was methylated in Weri-Rbl and Y79.The expression of IncRNA-MEG3 were significantly increased in Weri-Rbl and Y79 cells after treated with 5-Aza-CdR,and the cell proliferation ability was significantly reduced and the apoptosis capacity was significantly increased.After the intervention of 5-Aza-CdR and si-MEG3,the proliferation of Weri-Rbl and Y79 cells were significantly increased and the apoptosis were significantly reduced.Conclusion:The hypoexpression of MEG3 gene in retinoblastoma tissues and cells may be related to the hypermethylation of promoter DNA.4.The regulation of lncRNA-MEG3 in retinoblastoma cells on the activity of Wnt/?-catenin signaling pathway.Objective:To investigate whether lncRNA-MEG3 can regulate the activity of Wnt/?-catenin signaling pathway in retinoblastoma.Methods:The activity of Wnt/?-catenin signaling pathway and the expression of?-catenin were detected after the retinoblastoma cells were transfected with pcDNA-MEG3 or si-MEG3.The expression of ?-catenin,cell proliferation and apoptosis were detected after the activator or inhibitor of Wnt/?-catenin signaling pathway was used to reverse the effect of pcDNA-MEG3 or Si-MEG3 on Weri-Rbl and Y79 cells.Results:The luciferase activity and the expression of ?-catenin were significantly decreased in the Weri-Rb1 cells transfected with pcDNA-MEG3,while significantly increased in the Y79 cells transfected with si-MEG3.After the activation of Wnt/?-catenin signaling pathway,the inhibitory effect of pcDNA-MEG3 on Weri-Rbl cells was reversed.The effect of si-MEG3 on the carcinogenesis of Y79 cells was reversed after the inhibition of the Wnt/?-catenin signaling pathway.Conclusion:LncRNA-MEG3 as a tumor suppressor may inhibit the activity of Wnt/?-catenin signaling pathway to play a role.