The Interaction And Mechanism Of LSD1 And Notch Signaling Pathway In Esophageal Squamous Cell Carcinoma

Aim To explore the interaction and mechanism of LSD1 and Notch signaling pathway in esophageal squamous cell carcinoma(ESCC).Methods 1.The protein expression of LSD1 and the proteins associated with Notch signaling pathway in different ESCC cell lines.Expression of LSD1 and the proteins associated with Notch signaling pathway in ESCC cell line KYSE450,KYSE790,ECa109,EC9706 and TE1 cells were investigated by Western blots.2.The regulation effects of LSD1 to Notch signaling pathway.After ESCC cells were treated with LSD1 inhibitor TCP and LSD1 si RNA,respectively,the expressions of LSD1,histone H3K4me2 and the related proteins of Notch signaling pathway were detected by Western blots.3.The combination situations of LSD1 with promoters of Hes1,Notch3,DTX1 and CR2,which are the target genes of Notch signaling pathway,were detected by chromatin immunoprecipitation(Ch IP)in ECa109 cells.4.The effects of novel Notch pathway inhibitor FLI-06 on proliferation,apoptosis and cell cycle of ECa109 and EC9706 cells.The effects of FLI-06 on cell proliferations,cell apoptosis and cell cycle phase were detected by CCK-8 method,and flow cytometry,respectively.5.The regulation effects of Notch signaling pathway to LSD1.After ESCC cells were treated with FLI-06 and ?-secretase inhibitor GSI-DAPT in different concentrations,respectively,the expressions of Notch3,DTX1,Hes1 LSD1 and histone H3K4me2 were detected by Western blots.Results 1.There were expressions of LSD1 and proteins related with Notch signaling pathway in five ESCC cell lines,while the expression levels have differrence.2.After KYSE450,KYSE790,ECa109,EC9706 and TE1 cells were treated with TCP for 48 h,the expressions of LSD1 was down-regulated while H3K4me2 was up-regulated,and the related proteins of Notch signaling pathway were decreased.Similarly,LSD1 si RNA also down-regulated the expressions of LSD1 and the related proteins of Notch signaling pathway.3.Results of Ch IP validated that LSD1 could be combined with the regions of promoters of the Notch pathway target gene.4.FLI-06 inhibited the proliferations of ECa109 and EC9706 cells in a concentration-dependent manner.After ECa109 and EC9706 cells were treated with FLI-06 for 48 h,the IC50 were(5.814±0.053)?M and(10.741±0.049)?M,respectively.The results of flow cytometry analysis showed that after ECa109 and EC9706 cells were treated with FLI-06 for 48 h,the apoptosis rate of cells and the number of G1 phase cells increased significantly with the increase of drug concentration,which indicated that FLI-06 could induce cellular apoptosis and blocked cells in G1 phase.5.After ECa109 and EC9706 cells were treated with FLI-06 and GSI-DAPT,respectively,the expression of Notch3,DTX1 and Hes1 decreased significantly,which indicated that Notch signaling pathway was inhibited.The expression of LSD1 was decreased and H3K4me2 was not decreased.Conclusions 1.LSD1 has regulated effects on Notch signaling pathway in ESCC by binding to the promoter region of the Notch target gene.2.Notch signaling pathway has regulated effects on LSD1 in ESCC.