摘要
BACKGROUND Esophageal squamous cell carcinoma(ESCC),the predominant type of esophageal cancer,has a 5-year survival rate less than 20%.Although the cause of poor prognosis is the high incidence and mortality of ESCC,the high rate of metastasis after esophageal cancer surgery is the main cause of death after the surgery.Bromodomain-containing protein 4(BRD4),an epigenetic reader of chromatinacetylated histones in tumorigenesis and development,plays an essential role in regulating oncogene expression.BRD4 inhibition and BRD4 inhibition-based treatment can potentially suppress ESCC growth.However,the effects and mechanisms of action of BRD4 on ESCC cell migration remain unclear.AIM To explore the effect of BRD4 on cell migration of ESCC in vitro and its possible molecular mechanism.METHODS Human ESCC cell lines KYSE-450 and KYSE-150 were used.The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was performed to examine cell proliferation,and the transwell migration assay was conducted to test ESCC cell migration.JQ1,a BRD4 inhibitor,was applied to cells,and BRD4 siRNA was transfected into ESCC cells to knockdown endogenous BRD4.GFP-RFP-LC3 adenovirus was infected into ESCC cells to evaluate the effect of JQ1 on autophagy.Western blotting was performed to determine the protein levels of BRD4,E-cadherin,vimentin,AMP-activated protein kinase(AMPK),and p-AMPK.RESULTS BRD4 was either downregulated by small interfering RNA or pretreated with JQ1 in ESCC cells,leading to increased tumor migration in ESCC cells in a dose-and time-dependent manner.Inhibition of BRD4 not only significantly suppressed cell proliferation but also strongly increased cell migration by inducing epithelial-mesenchymal transition(EMT).The protein expression of vimentin was increased and E-cadherin decreased in a dose-dependent manner,subsequently promoting autophagy in KYSE-450 and KYSE-150 cells.Pretreatment with JQ1,a BRD4 inhibitor,inhibited BRD4-induced LC3-II activation and upregulated AMPK phosphorylation in a dosedepend
基金
the Key Project of Science and Technology of Xinxiang,No.GG2020027
the Health Commission of Henan Province of China,No.SBGJ202102188.
