Role And Mechanism Of EP300 In The Development Of Esophageal Squamous Cell Carcinoma

Objective:To study the function and mechanism of EP300 in ESCC.Methods:1.Integrated analysis of 35 histone modifier gene mutations in 425 ESCC patients from 4 Chinese cohorts.2.The protein expression level of EP300 in ESCC was tested by tissue chip and immunohistochemistry technology,and the relationship between its expression level and various clinical parameters was analyzed through Rank-sum test,Log-rank test,Cox regression,etc.3.RT-qPCR and Western blot were used to detect the expression level of EP300 in different ESCC cell lines.KYSE140 and KYSE180 with high endogenous expression were screened out to knockdown the expression of EP300 with small interfering RNA.4.MTT,Transwell,clonal formation and wound healing were used to detect the functional phenotype indeuced by EP300 knockdown in ESCC cell lines.5.RNA-seq technology was used to screen the significantly different genes for enrichment analysis of functions and pathways after EP300 was knocked down.6.Significantly changed genes in epithelial-mesenchymal transformation,angiogenesis and hypoxia pathways were detected by RT-qPCR to verify the regulatory effects of EP300 on these three phenotypes in ESCC cell lines.Results:1.Of these histone modifier genes,seven genes have higher mutation frequency more than 5% in ESCC.And the mutation frequency of EP300 was 10.8%.The ESCC patients with EP300 mutation had poor survival time than those with wild type EP300(p = 0.026).2.The expression level of EP300 in cancer tissues was significantly higher than that in paired adjacent normal tissues.The ESCC patients with high EP300 expression had poor survival time than those with wild low EP300(p = 0.048).3.Among the nine ESCC cell lines tested,KYSE140 and KYSE180 cell lines showed relatively high endogenous expression of EP300.4.EP300 knockdown inhibited cell proliferation,migration and invasion in ESCC cell lines.5.After EP300 knockdown,the significantly different genes were mainly enriched in the signaling pathways related to epithelial-mesenchymal transition,angiogenesis and hypoxia.6.EP300 knockdown inhibited the epithelial-mesenchymal transformation,angiogenesis and hypoxia metabolism of ESCC cells.Conclusion:Knockdown EP300 may play an anticancer role on ESCC by inhibiting the epithelial-mesenchymal transformation,angiogenesis and hypoxia metabolism.