OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mech...OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mechanisms.METHODS BRD4 interactors were analyzed by PPI network prediction and The Cancer Genome Atlas(TCGA)analysis.The interaction between BRD4 and AMPK was confirmed by co-immunoprecipitation assay.Novel BRD4 inhibitors were designed and synthesized based upon pharmacophore analysis of BRD4(1),then screened by antiproliferative activity and Alpha Screen of BRD4(1).The selectivity of the best candidate compound 8f was validated by co-crystallization,FRET assay and co-immuno precipitation assay.The mechanisms of 8f were investigated by fluorescence microscopy,electron microscopy,Western blotting,immunocytochemistry,si RNA and GFP-m RFP-LC3 plasmid transfections,as well as immunohistochemistry and immunofluorescence.Potential mechanisms were discovered by i TRAQ-based proteomics analysis and the therapeutic effect of 8f was assessed by xenograft breast cancer mouse and zebrafish models.RESULTS We identified that BRD4 interacted with AMPK,which was remarkably downregulated in breast cancer.We next designed and synthesized 49 candidate compounds,and eventually discovered a selective small-molecule inhibitor of BRD4(8f).Subsequently,8f was discovered to induce autophagyassociated cell death(ACD)by BRD4-AMPK interaction,and thus activating AMPK-m TOR-ULK1-modulated autophagic pathway in breast cancer cells.Interestingly,the i TRAQ-based proteomics analyses revealed that 8f induced ACD pathways,involved in HMGB1,VDAC1/2 and e EF2.Moreover,8f displayed a therapeutic potential on both xenograft breast cancer mouse and zebrafish models.CONCLUSION We discovered a novel small-molecule inhibitor of BRD4 that induces BRD4-AMPK-modulated ACD in breast cancer,which may provide a candidate drug for future cancer therapy.展开更多
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,t...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 dosedependent manner.Additionally,an increased number of autophagosomes and autolysosomes were observed in JQ1-treated ESCC cells.The autophagy inhibitor 3-methyladenine(3-MA)reversed the effects of BRD4 knockdown on ESCC cell migration and blocked JQ1-induced cell migration.3-MA also downregulated the expression of vimentin and upregulation E-cadherin.CONCLUSION BRD4 inhibition enhances cell migration by inducing EMT and autophagy in ESCC cells via the AMPK-modified pathway.Thus,the facilitating role on ESCC cell migration should be considered for BRD4 inhibitor clinical application to ESCC patients.展开更多
AIM:To explore the therapeutic effect and main molecular mechanisms of acteoside in a glaucoma model in DBA/2J mice.METHODS:Proteomics was used to compare the differentially expressed proteins of C57 and DBA/2J mice.A...AIM:To explore the therapeutic effect and main molecular mechanisms of acteoside in a glaucoma model in DBA/2J mice.METHODS:Proteomics was used to compare the differentially expressed proteins of C57 and DBA/2J mice.After acteoside administration in DBA/2J mice,anterior segment observation,intraocular pressure(IOP)monitoring,electrophysiology examination,and hematoxylin and eosin staining were used to analyze any potential effects.Immunohistochemistry(IHC)assays were used to verify the proteomics results.Furthermore,retinal ganglion cell 5(RGC5)cell proliferation was assessed with cell counting kit-8(CCK-8)assays.Serta domain-containing protein 4(Sertad4)mRNA and protein expression levels were measured by qRT-PCR and Western blot analysis,respectively.RESULTS:Proteomics analysis suggested that Sertad4 was the most significantly differentially expressed protein.Compared with the saline group,the acteoside treatment group showed decreased IOP,improved N1-P1 wave amplitudes,thicker retina,and larger numbers of cells in the ganglion cell layer(GCL).The IHC results showed that Sertad4 expression levels in DBA/2J mice treated with acteoside were significantly lower than in the saline group.Acteoside treatment could improve RGC5 cell survival and reduce the Sertad4 mRNA and protein expression levels after glutamate injury.CONCLUSION:Sertad4 is differentially expressed in DBA/2J mice.Acteoside can protect RGCs from damage,possibly through the downregulation of Sertad4,and has a potential use in glaucoma treatment.展开更多
BACKGROUND Heat shock protein A4(HSPA4)belongs to molecular chaperone protein family which plays important roles within variable cellular activities,including cancer initiation and progression.However,the prognostic a...BACKGROUND Heat shock protein A4(HSPA4)belongs to molecular chaperone protein family which plays important roles within variable cellular activities,including cancer initiation and progression.However,the prognostic and immunological significance of HSPA4 in lung adenocarcinoma(LUAD)has not been revealed yet.AIM To explore the prognostic and immunological roles of HSPA4 to identify a novel prognostic biomarker and therapeutic target for LUAD.METHODS We assessed the prognostic and immunological significance of HSPA4 in LUAD using data from The Cancer Genome Atlas database.The association between HSPA4 expression and clinical-pathological features was assessed through Kruskal-Wallis and Wilcoxon signed-rank test.Univariate/multivariate Cox regression analyses and Kaplan-Meier curves were employed to evaluate prognostic factors,including HSPA4,in LUAD.Gene set enrichment analysis(GSEA)was conducted to identify the key signaling pathways associated with HSPA4.The correlation between HSPA4 expression and cancer immune infiltration was evaluated using single-sample gene set enrichment analysis(ssGSEA).RESULTS Overexpressing HSPA4 was significantly related to advanced pathologic TNM stage,advanced pathologic stage,progression disease status of primary therapy outcome and female subgroups with LUAD.In addition,increased HSPA4 expression was found to be related to worse disease-specific survival and overall survival.GSEA analysis indicated a significant correlation between HSPA4 and cell cycle regulation and immune response,particularly through diminishing the function of cytotoxicity cells and CD8 T cells.The ssGSEA algorithm showed a positive correlation between HSPA4 expression and infiltrating levels of Th2 cells,while a negative correlation was observed with cytotoxic cell infiltration levels.CONCLUSION Our findings indicate HSPA4 is related to prognosis and immune cell infiltrates and may act as a novel prognostic biomarker and therapeutic target for LUAD.展开更多
目的研究程序性细胞死亡蛋白4(programmed cell death protein 4,PDCD4)在脓毒症诱导的急性肾损伤(acute kidney injury,AKI)中的作用机制,以及调控PDCD4表达通过丝裂原活化蛋白激酶3(mitogen-activated protein kinase 3,MAP2K3)和p38...目的研究程序性细胞死亡蛋白4(programmed cell death protein 4,PDCD4)在脓毒症诱导的急性肾损伤(acute kidney injury,AKI)中的作用机制,以及调控PDCD4表达通过丝裂原活化蛋白激酶3(mitogen-activated protein kinase 3,MAP2K3)和p38蛋白激酶(p38 mitogen-activated protein kinase,p38 MAPK)对脓毒症AKI起到潜在治疗作用。方法用脂多糖(lipopolysaccharide,LPS)刺激人肾小管上皮细胞(HK-2)构建脓毒症AKI细胞模型。进一步用腺病毒介导siRNA和过表达载体抑制和上调AKI细胞模型中PDCD4的表达;CCK-8法检测细胞增殖;用DCFH-DA及激光共聚焦显微镜检测细胞中ROS水平,用总SOD活性检测试剂和MDA检测试剂盒检测细胞中SOD和MDA水平;免疫共沉淀验证PDCD4和MAP2K3之间的蛋白相互作用;TUNEL染色法检测细胞凋亡;RT-qPCR和Western blot检测PDCD4及相关基因的mRNA和蛋白表达水平;ELISA法检测患者血清中炎症相关因子水平。结果LPS诱导可以促进HK-2细胞中PDCD4表达,下调PDCD4可抑制LPS诱导的HK-2细胞的炎症、氧化应激及细胞凋亡。数据库预测及免疫共沉淀证实PDCD4可以与MAP2K3相互作用,且在LPS诱导的HK-2细胞中,MAP2K3表达水平显著增强。MAP2K3过表达和p38 MAPK激动剂可以减轻PDCD4下调对LPS诱导的细胞炎症和氧化应激的影响并抑制细胞凋亡。结论下调PDCD4可以通过抑制MAP2K3和p38 MAPK从而抑制LPS诱导的肾小管上皮细胞的炎症和凋亡。展开更多
基金supported by National Natural Science Foundation of China(81473091,81673290 and U1603123)
文摘OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mechanisms.METHODS BRD4 interactors were analyzed by PPI network prediction and The Cancer Genome Atlas(TCGA)analysis.The interaction between BRD4 and AMPK was confirmed by co-immunoprecipitation assay.Novel BRD4 inhibitors were designed and synthesized based upon pharmacophore analysis of BRD4(1),then screened by antiproliferative activity and Alpha Screen of BRD4(1).The selectivity of the best candidate compound 8f was validated by co-crystallization,FRET assay and co-immuno precipitation assay.The mechanisms of 8f were investigated by fluorescence microscopy,electron microscopy,Western blotting,immunocytochemistry,si RNA and GFP-m RFP-LC3 plasmid transfections,as well as immunohistochemistry and immunofluorescence.Potential mechanisms were discovered by i TRAQ-based proteomics analysis and the therapeutic effect of 8f was assessed by xenograft breast cancer mouse and zebrafish models.RESULTS We identified that BRD4 interacted with AMPK,which was remarkably downregulated in breast cancer.We next designed and synthesized 49 candidate compounds,and eventually discovered a selective small-molecule inhibitor of BRD4(8f).Subsequently,8f was discovered to induce autophagyassociated cell death(ACD)by BRD4-AMPK interaction,and thus activating AMPK-m TOR-ULK1-modulated autophagic pathway in breast cancer cells.Interestingly,the i TRAQ-based proteomics analyses revealed that 8f induced ACD pathways,involved in HMGB1,VDAC1/2 and e EF2.Moreover,8f displayed a therapeutic potential on both xenograft breast cancer mouse and zebrafish models.CONCLUSION We discovered a novel small-molecule inhibitor of BRD4 that induces BRD4-AMPK-modulated ACD in breast cancer,which may provide a candidate drug for future cancer therapy.
基金the Key Project of Science and Technology of Xinxiang,No.GG2020027the Health Commission of Henan Province of China,No.SBGJ202102188.
文摘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 dosedependent manner.Additionally,an increased number of autophagosomes and autolysosomes were observed in JQ1-treated ESCC cells.The autophagy inhibitor 3-methyladenine(3-MA)reversed the effects of BRD4 knockdown on ESCC cell migration and blocked JQ1-induced cell migration.3-MA also downregulated the expression of vimentin and upregulation E-cadherin.CONCLUSION BRD4 inhibition enhances cell migration by inducing EMT and autophagy in ESCC cells via the AMPK-modified pathway.Thus,the facilitating role on ESCC cell migration should be considered for BRD4 inhibitor clinical application to ESCC patients.
基金Supported by Tianjin Key Medical Discipline(Specialty)Construction Project(No.TJYXZDXK-037A).
文摘AIM:To explore the therapeutic effect and main molecular mechanisms of acteoside in a glaucoma model in DBA/2J mice.METHODS:Proteomics was used to compare the differentially expressed proteins of C57 and DBA/2J mice.After acteoside administration in DBA/2J mice,anterior segment observation,intraocular pressure(IOP)monitoring,electrophysiology examination,and hematoxylin and eosin staining were used to analyze any potential effects.Immunohistochemistry(IHC)assays were used to verify the proteomics results.Furthermore,retinal ganglion cell 5(RGC5)cell proliferation was assessed with cell counting kit-8(CCK-8)assays.Serta domain-containing protein 4(Sertad4)mRNA and protein expression levels were measured by qRT-PCR and Western blot analysis,respectively.RESULTS:Proteomics analysis suggested that Sertad4 was the most significantly differentially expressed protein.Compared with the saline group,the acteoside treatment group showed decreased IOP,improved N1-P1 wave amplitudes,thicker retina,and larger numbers of cells in the ganglion cell layer(GCL).The IHC results showed that Sertad4 expression levels in DBA/2J mice treated with acteoside were significantly lower than in the saline group.Acteoside treatment could improve RGC5 cell survival and reduce the Sertad4 mRNA and protein expression levels after glutamate injury.CONCLUSION:Sertad4 is differentially expressed in DBA/2J mice.Acteoside can protect RGCs from damage,possibly through the downregulation of Sertad4,and has a potential use in glaucoma treatment.
文摘BACKGROUND Heat shock protein A4(HSPA4)belongs to molecular chaperone protein family which plays important roles within variable cellular activities,including cancer initiation and progression.However,the prognostic and immunological significance of HSPA4 in lung adenocarcinoma(LUAD)has not been revealed yet.AIM To explore the prognostic and immunological roles of HSPA4 to identify a novel prognostic biomarker and therapeutic target for LUAD.METHODS We assessed the prognostic and immunological significance of HSPA4 in LUAD using data from The Cancer Genome Atlas database.The association between HSPA4 expression and clinical-pathological features was assessed through Kruskal-Wallis and Wilcoxon signed-rank test.Univariate/multivariate Cox regression analyses and Kaplan-Meier curves were employed to evaluate prognostic factors,including HSPA4,in LUAD.Gene set enrichment analysis(GSEA)was conducted to identify the key signaling pathways associated with HSPA4.The correlation between HSPA4 expression and cancer immune infiltration was evaluated using single-sample gene set enrichment analysis(ssGSEA).RESULTS Overexpressing HSPA4 was significantly related to advanced pathologic TNM stage,advanced pathologic stage,progression disease status of primary therapy outcome and female subgroups with LUAD.In addition,increased HSPA4 expression was found to be related to worse disease-specific survival and overall survival.GSEA analysis indicated a significant correlation between HSPA4 and cell cycle regulation and immune response,particularly through diminishing the function of cytotoxicity cells and CD8 T cells.The ssGSEA algorithm showed a positive correlation between HSPA4 expression and infiltrating levels of Th2 cells,while a negative correlation was observed with cytotoxic cell infiltration levels.CONCLUSION Our findings indicate HSPA4 is related to prognosis and immune cell infiltrates and may act as a novel prognostic biomarker and therapeutic target for LUAD.
文摘目的研究程序性细胞死亡蛋白4(programmed cell death protein 4,PDCD4)在脓毒症诱导的急性肾损伤(acute kidney injury,AKI)中的作用机制,以及调控PDCD4表达通过丝裂原活化蛋白激酶3(mitogen-activated protein kinase 3,MAP2K3)和p38蛋白激酶(p38 mitogen-activated protein kinase,p38 MAPK)对脓毒症AKI起到潜在治疗作用。方法用脂多糖(lipopolysaccharide,LPS)刺激人肾小管上皮细胞(HK-2)构建脓毒症AKI细胞模型。进一步用腺病毒介导siRNA和过表达载体抑制和上调AKI细胞模型中PDCD4的表达;CCK-8法检测细胞增殖;用DCFH-DA及激光共聚焦显微镜检测细胞中ROS水平,用总SOD活性检测试剂和MDA检测试剂盒检测细胞中SOD和MDA水平;免疫共沉淀验证PDCD4和MAP2K3之间的蛋白相互作用;TUNEL染色法检测细胞凋亡;RT-qPCR和Western blot检测PDCD4及相关基因的mRNA和蛋白表达水平;ELISA法检测患者血清中炎症相关因子水平。结果LPS诱导可以促进HK-2细胞中PDCD4表达,下调PDCD4可抑制LPS诱导的HK-2细胞的炎症、氧化应激及细胞凋亡。数据库预测及免疫共沉淀证实PDCD4可以与MAP2K3相互作用,且在LPS诱导的HK-2细胞中,MAP2K3表达水平显著增强。MAP2K3过表达和p38 MAPK激动剂可以减轻PDCD4下调对LPS诱导的细胞炎症和氧化应激的影响并抑制细胞凋亡。结论下调PDCD4可以通过抑制MAP2K3和p38 MAPK从而抑制LPS诱导的肾小管上皮细胞的炎症和凋亡。
