Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most mal...Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most malignant tumors and promotes cancer cell growth.Heat shock protein 90(HSP90)is an important molecular chaperone in the conformational maturation and stabilization of numerous proteins involved in cell growth or survival.Methods:DDX5 m RNA and protein expression in surgically resected HCC tissues from 24 Asian patients were detected by quantitative real-time PCR and Western blot,respectively.The interaction of DDX5-HSP90 was determined by molecular docking,immunoprecipitation,and laser scanning confocal microscopy.The autophagy signal was detected by Western blot.The cell functions and signaling pathways of DDX5 were determined in 2 HCC cell lines.Two different murine HCC xenograft models were used to determine the function of DDX5 and the therapeutic effect of an HSP90 inhibitor.Results:HSP90 interacted directly with DDX5 and inhibited DDX5 protein degradation in the AMPK/ULK1-regulated autophagy pathway.The subsequent accumulation of DDX5 protein induced the malignant phenotype of HCC by activating theβ-catenin signaling pathway.The silencing of DDX5 or treatment with HSP90 inhibitor both blocked in vivo tumor growth in a murine HCC xenograft model.High levels of HSP90 and DDX5 protein were associated with poor prognoses.Conclusions:HSP90 interacted with DDX5 protein and subsequently protected DDX5 protein from AMPK/ULK1-regulated autophagic degradation.DDX5 and HSP90 are therefore potential therapeutic targets for HCC.展开更多
Pancreatic cancer is one of the deadliest cancers with a very poor prognosis. Recently, there has been a significant increase in research directed towards identifying potential biomarkers that can be used to diagnose ...Pancreatic cancer is one of the deadliest cancers with a very poor prognosis. Recently, there has been a significant increase in research directed towards identifying potential biomarkers that can be used to diagnose and provide prognostic information for pancreatic cancer. These markers can be used clinically to optimize and personalize therapy for individual patients. In this review, we focused on 3 biomarkers involved in the DNA damage response pathway and the necroptosis pathway: Chromodomainhelicase-DNA binding protein 5, chromodomain-helicaseDNA binding protein 7, and mixed lineage kinase domain-like protein. The aim of this article is to review present literature provided for these biomarkers and current studies in which their effectiveness as prognostic biomarkers are analyzed in order to determine their future use as biomarkers in clinical medicine. Based on the data presented, these biomarkers warrant further investigation,and should be validated in future studies.展开更多
Hepatitis C virus(HCV)helicase is a molecular motor that splits nucleic acid duplex structures during viral replication,therefore representing a promising target for antiviral treatment.Hence,a detailed understanding ...Hepatitis C virus(HCV)helicase is a molecular motor that splits nucleic acid duplex structures during viral replication,therefore representing a promising target for antiviral treatment.Hence,a detailed understanding of the mechanism by which it operates would facilitate the development of efficient drug-assisted therapies aiming to inhibit helicase activity.Despite extensive investigations performed in the past,a thorough understanding of the activity of this important protein was lacking since the underlying internal conformational motions could not be resolved.Here we review investigations that have been previously performed by us for HCV helicase.Using methods of structure-based computational modelling it became possible to follow entire operation cycles of this motor protein in structurally resolved simulations and uncover the mechanism by which it moves along the nucleic acid and accomplishes strand separation.We also discuss observations from that study in the light of recent experimental studies that confirm our findings.展开更多
RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or...RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or re-folding the viral RNA elements.Coxsackieviruses B3(CVB3)and Coxsackieviruses B5(CVB5),belonging to the genus Enterovirus in the family Picornaviridae,have been reported to cause various infectious diseases such as hand-foot-and-mouth disease,aseptic meningitis,and viral myocarditis.However,little is known about whether CVB3 and CVB5 encode any RNA remodeling proteins.In this study,we showed that 2C proteins of CVB3 and CVB5 contained the conserved SF3 helicase A,B,and C motifs,and functioned not only as RNA helicase that unwound RNA helix bidirectionally in an NTP-dependent manner,but also as RNA chaperone that remodeled structured RNAs and facilitated RNA strand annealing independently of NTP.In addition,we determined that the NTPase activity and RNA helicase activity of 2C proteins of CVB3 and CVB5 were dependent on the presence of divalent metallic ions.Our findings demonstrate that 2C proteins of CVBs possess RNA-remodeling activity and underline the functional importance of 2C protein in the life cycle of CVBs.展开更多
目的预测卵巢癌抑癌基因HELQ编码蛋白(HELQ蛋白)的结构和功能。方法采用Ex PASy服务器中的工具分析HELQ蛋白的理化特征。分别采用PSORTⅡ和TMHMM预测HELQ蛋白的亚细胞定位和跨膜拓扑结构。采用Signal P 4.0预测HELQ蛋白的信号肽。采用Sc...目的预测卵巢癌抑癌基因HELQ编码蛋白(HELQ蛋白)的结构和功能。方法采用Ex PASy服务器中的工具分析HELQ蛋白的理化特征。分别采用PSORTⅡ和TMHMM预测HELQ蛋白的亚细胞定位和跨膜拓扑结构。采用Signal P 4.0预测HELQ蛋白的信号肽。采用Scan Prosite和SMART分析HELQ蛋白的功能结构域以及结构域分区。采用PSIPRED和I-TASSER预测HELQ蛋白的二级和三级结构以及配体结合位点。采用STRING10.0预测HELQ蛋白与其他蛋白的交互作用。结果 HELQ蛋白主要定位在细胞核(47.8%)和细胞质(39.1%)中,有4个保守结构域DEXDc、HELICc、HHH_5和PRK02362,并包含解旋酶ATP结合区和解旋酶C端结合区两个功能结构域;成功建立了HELQ蛋白的二级和三级结构模型,其中二级结构中α螺旋、无规则卷曲及折叠结构比例分别为54%、31%和6%。三维配体结构分析发现HELQ蛋白包含一个酶活性中心位点His341,催化Ile333、Lys335、Tyr337、Gln340、Pro360、Thr361、Ser362、Gly363、Gly364、Lys365、Thr366、Leu367、Glu464和Ala711等结合位点与配体ATP结合。交联蛋白质分析发现HELQ蛋白可能与RAD51、POLA1、PLON、FANCD2、DHX8等蛋白存在交互作用。结论 HELQ蛋白可能具有ATP依赖性解旋酶的结构和功能,参与DNA损伤的修复过程。展开更多
目的:探讨染色质解旋酶DNA结合蛋白1样基因(chromodomain helicase/ATPase DNA binding protein 1-like gene,CHD1L)对前列腺癌细胞侵袭、迁移能力的影响及其可能的作用机制。方法:采用实时荧光定量PCR技术检测前列腺癌细胞株LNCAP、PC3...目的:探讨染色质解旋酶DNA结合蛋白1样基因(chromodomain helicase/ATPase DNA binding protein 1-like gene,CHD1L)对前列腺癌细胞侵袭、迁移能力的影响及其可能的作用机制。方法:采用实时荧光定量PCR技术检测前列腺癌细胞株LNCAP、PC3、DU145以及前列腺上皮细胞株RWPE-1中CHD1L mRNA表达水平;转染siRNA干扰前列腺癌PC3细胞CHD1L的表达,并用Transwell侵袭实验和划痕实验分析沉默CHD1L对前列腺癌细胞侵袭和迁移能力的影响;Western blotting检测PC3细胞MMP-9、N-钙黏蛋白和E-钙黏蛋白的表达水平。结果:CHD1L mRNA在前列腺癌细胞中的表达水平明显高于前列腺上皮细胞(P<0.01),其中以前列腺癌PC3细胞的表达水平最高。侵袭实验中,干扰组的穿膜细胞数明显低于阴性对照组和空白对照组[(49.67±6.67)vs(113.67±5.69)和(112.00±12.49)个,P<0.05)。划痕实验中,干扰组48 h伤口愈合率也低于阴性对照组和空白对照组[(21.27±3.27)%vs(48.47±5.72)%和(49.93±3.35)%,P<0.05]。干扰组细胞MMP-9和N-钙黏蛋白表达下调,E-钙黏蛋白表达上调。结论:沉默CHD1L可降低前列腺癌PC3细胞的侵袭迁移能力,该作用可能是通过调控MMP-9和EMT相关蛋白表达实现的。展开更多
基金funding support from the National Natural Science Foundation of China(Grant Nos.81672467,81702773,81702389,and 81672368)the Major National R&D Project(Grant Nos.2018ZX10723204,2018ZX10302205,and 2018ZX09J18107)the Natural Science Foundation of Beijing(Grant No.7172207)。
文摘Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most malignant tumors and promotes cancer cell growth.Heat shock protein 90(HSP90)is an important molecular chaperone in the conformational maturation and stabilization of numerous proteins involved in cell growth or survival.Methods:DDX5 m RNA and protein expression in surgically resected HCC tissues from 24 Asian patients were detected by quantitative real-time PCR and Western blot,respectively.The interaction of DDX5-HSP90 was determined by molecular docking,immunoprecipitation,and laser scanning confocal microscopy.The autophagy signal was detected by Western blot.The cell functions and signaling pathways of DDX5 were determined in 2 HCC cell lines.Two different murine HCC xenograft models were used to determine the function of DDX5 and the therapeutic effect of an HSP90 inhibitor.Results:HSP90 interacted directly with DDX5 and inhibited DDX5 protein degradation in the AMPK/ULK1-regulated autophagy pathway.The subsequent accumulation of DDX5 protein induced the malignant phenotype of HCC by activating theβ-catenin signaling pathway.The silencing of DDX5 or treatment with HSP90 inhibitor both blocked in vivo tumor growth in a murine HCC xenograft model.High levels of HSP90 and DDX5 protein were associated with poor prognoses.Conclusions:HSP90 interacted with DDX5 protein and subsequently protected DDX5 protein from AMPK/ULK1-regulated autophagic degradation.DDX5 and HSP90 are therefore potential therapeutic targets for HCC.
基金Supported by The National Center for Advancing Translational Sciences of the National Institutes of Health under award numbers ULl TR000454 previously awarded to Dr.Colbert and Dr.Fisher and TLlT R000456 to Dr.ColbertPancreatic Cancer Action Network(Pan-CAN)&sol American Association for Cancer Research(AACR)award 16982+1 种基金Department of Defense(DOD)/Peer Reviewed Cancer Research Program(PRCRP)award CA110535Georgia Cancer Coalition award 11072,all to Dr.Yu
文摘Pancreatic cancer is one of the deadliest cancers with a very poor prognosis. Recently, there has been a significant increase in research directed towards identifying potential biomarkers that can be used to diagnose and provide prognostic information for pancreatic cancer. These markers can be used clinically to optimize and personalize therapy for individual patients. In this review, we focused on 3 biomarkers involved in the DNA damage response pathway and the necroptosis pathway: Chromodomainhelicase-DNA binding protein 5, chromodomain-helicaseDNA binding protein 7, and mixed lineage kinase domain-like protein. The aim of this article is to review present literature provided for these biomarkers and current studies in which their effectiveness as prognostic biomarkers are analyzed in order to determine their future use as biomarkers in clinical medicine. Based on the data presented, these biomarkers warrant further investigation,and should be validated in future studies.
文摘Hepatitis C virus(HCV)helicase is a molecular motor that splits nucleic acid duplex structures during viral replication,therefore representing a promising target for antiviral treatment.Hence,a detailed understanding of the mechanism by which it operates would facilitate the development of efficient drug-assisted therapies aiming to inhibit helicase activity.Despite extensive investigations performed in the past,a thorough understanding of the activity of this important protein was lacking since the underlying internal conformational motions could not be resolved.Here we review investigations that have been previously performed by us for HCV helicase.Using methods of structure-based computational modelling it became possible to follow entire operation cycles of this motor protein in structurally resolved simulations and uncover the mechanism by which it moves along the nucleic acid and accomplishes strand separation.We also discuss observations from that study in the light of recent experimental studies that confirm our findings.
基金supported by the National Natural Science Foundation of China (82002155 to T.S., and U21A20423 and 31670161 to X.Z.)
文摘RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or re-folding the viral RNA elements.Coxsackieviruses B3(CVB3)and Coxsackieviruses B5(CVB5),belonging to the genus Enterovirus in the family Picornaviridae,have been reported to cause various infectious diseases such as hand-foot-and-mouth disease,aseptic meningitis,and viral myocarditis.However,little is known about whether CVB3 and CVB5 encode any RNA remodeling proteins.In this study,we showed that 2C proteins of CVB3 and CVB5 contained the conserved SF3 helicase A,B,and C motifs,and functioned not only as RNA helicase that unwound RNA helix bidirectionally in an NTP-dependent manner,but also as RNA chaperone that remodeled structured RNAs and facilitated RNA strand annealing independently of NTP.In addition,we determined that the NTPase activity and RNA helicase activity of 2C proteins of CVB3 and CVB5 were dependent on the presence of divalent metallic ions.Our findings demonstrate that 2C proteins of CVBs possess RNA-remodeling activity and underline the functional importance of 2C protein in the life cycle of CVBs.
