Objective Osteosarcoma is the most common type of malignant bone tumor in children and adolescents. The role of E3 ligases in tumorigenesis is currently a focus in tumor research. In the present study, we investigated...Objective Osteosarcoma is the most common type of malignant bone tumor in children and adolescents. The role of E3 ligases in tumorigenesis is currently a focus in tumor research. In the present study, we investigated the role of the E3 ligase tripartite motif 21（TRIM21） in osteosarcoma cell proliferation.Methods 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide（MTT） assays were used to assess osteosarcoma cell viability. U2-OS cells stably carrying a recombinant lentivirus expressing tetracycline-regulated TRIM21 were screened. Co-immunoprecipitation was coupled with LCMS/MS analysis to identify novel interacting partners of TRIM21. Co-immunoprecipitation and bimolecular fluorescence complementation（BIFC） were performed to validate the interactions between TRIM21 and its novel partner YWHAZ. A TRIM21-ΔRING construct was generated to test the effects of TRIM21 ligase activity on YWHAZ.Results TRIM21 positively regulated osteosarcoma cell proliferation. Overexpression of TRIM21 enhanced osteosarcoma cell tolerance toward various stresses. YWHAZ protein was identified as a novel interacting partner of TRIM21 and its expression levels were negatively regulated by TRIM21. The RING domain of TRIM21 was required for TRIM21 negative regulation of YWHAZ expression. However,overexpression of YWHAZ did not affect positive regulation of osteosarcoma cell proliferation by TRIM21.Conclusion Our results further clarify the molecular mechanisms underlying the pathogenesis of osteosarcoma.展开更多
Tripartite motif 21(TRIM21)is an E3 ubiquitin ligase that shows great promise for protein degradation through ubiquitination.Here,ultrasmall chiral gold nanoparticles(D-or L-NPs)modified by D-or L-glutathione ligands ...Tripartite motif 21(TRIM21)is an E3 ubiquitin ligase that shows great promise for protein degradation through ubiquitination.Here,ultrasmall chiral gold nanoparticles(D-or L-NPs)modified by D-or L-glutathione ligands were fabricated.After conjugated with an NLR family pyrin domain-containing protein 3(NLRP3)antibody(D-NP-a NLRP3 or L-NP-a NLRP3),DNP-a NLRP3 showed effective delivery efficiency of the antibody into microglia and prevented Aβ-mediated microglia senescence,and p16^(ink4a),a marker of senescence,in the microglia was reduced by 90.3%±7.8% while L-NP-a NLRP3 decreased by 48.01%±3.1%.Mechanistic investigations revealed that the D-NP-a NLRP3((1.5±0.3)×10^(7)M^(-1))exhibited sixteen-fold larger binding affinity to transmembrane glycoprotein SLC3A2 than L-type((9.5±2.7)×10^(5)M^(-1)),which led to a high efficiency of antibody delivery and TRIM21-dependent NLRP3 degradation.Notably,the blood-brain barrier(BBB)-crossing ability of chiral NP-a NLRP3 as well as NLRP3 degradation was demonstrated in vivo.The APP/PS1 Alzheimer's disease(AD)model mice experiments exhibited a reduction of 89.7%±6.8% for the NLRP3 protein and 84.2±7.5% for p16^(ink4a)following the intravenous administration of D-NP-a NLRP3 once a week for 60 days.Furthermore,the levels of the AD markers Aβ and phosphorylatedTau in the brains were reduced by 86.2%±8.2% and 81.6%±9.1%;these were 2.1-fold and 1.9-fold higher than those treated with L-NP-a NLRP3,respectively.The studies provide a method to rescue AD-like pathologies and prevent senescence.展开更多
Background:Previous studies have revealed the critical role of transglutaminase 2(TGM2)as a potential therapeutic target in cancers,but the oncogenic roles and underlying mechanisms of TGM2 in gastric cancer(GC)are no...Background:Previous studies have revealed the critical role of transglutaminase 2(TGM2)as a potential therapeutic target in cancers,but the oncogenic roles and underlying mechanisms of TGM2 in gastric cancer(GC)are not fully understood.In this study,we examined the role and potential mechanism of TGM2 in GC.Methods:Western blotting,immunohistochemistry,CCK8,colony formation and transwell assays were used to measure TGM2 expression in the GC cells and tissues and to examine the in vitro role of TGM2 in GC.Xenograft and in vivo metastasis experiments were performed to examine the in vivo role of TGM2 in GC.Gene set enrichment analysis,quantitative PCR and western blotting were conducted to screen for potential TGM2 targets involved in GC.Gain/loss-offunction and rescue experiments were conducted to detect the biological roles of STAT1 in GC cells in the context of TGM2.Co-immunoprecipitation,mass spectrometry,quantitative PCR and western blotting were conducted to identify STAT1-interacting proteins and elucidate their regulatory mechanisms.Mutations in TGM2 and two molecules(ZM39923 and A23187)were used to identify the enzymatic activity of TGM2 involved in the malignant progression of GC and elucidate the underlying mechanism.Results:In this study,we demonstrated elevated TGM2 expression in the GC tissues,which closely related to pathological grade,and predicted poor survival in patients with GC.TGM2 overexpression or knockdown promoted(and inhibited)cell proliferation,migration,and invasion,which were reversed by STAT1 knockdown or overexpression.Further studies showed that TGM2 promoted GC progression by inhibiting STAT1 ubiquitination/degradation.Then,tripartite motif-containing protein 21(TRIM21)was identified as a ubiquitin E3 ligase of STAT1 in GC.TGM2 maintained STAT1 stability by facilitating the dissociation of TRIM21 and STAT1 with GTP-binding enzymatic activity.A23187 abolished the role of TGM2 in STAT1 and reversed the pro-tumor role of TGM2 in vitro and in vivo.Conclusions:This study revealed a critical role and regulatory mechanism of TGM2 on STAT1 in GC and highlighted the potential of TGM2 as a therapeutic target,which elucidates the development of medicine or strategies by regulating the GTP-binding activity of TGM2 in GC.展开更多
Background:Hepatocellular carcinoma(HCC)is one of the most common malignant tumors in the world.The ubiquitin-specific peptidase 25(USP25)protein has been reported to participate in the development of several cancers....Background:Hepatocellular carcinoma(HCC)is one of the most common malignant tumors in the world.The ubiquitin-specific peptidase 25(USP25)protein has been reported to participate in the development of several cancers.However,few studies have reported its association with HCC.In this study,we aimed to investigate the function and mechanism of USP25 in the progression of HCC.Methods:We analyzed USP25 protein expression in HCC based on The Cancer Genome Atlas(TCGA)and International Cancer Genome Consortium(ICGC)database cohorts.Then,we constructed USP25-overexpressing and USP25-knockdown HepG2,MHCC97H,and L-O2 cells.We detected the biological function of USP25 by performing a series of assays,such as Cell Counting Kit-8(CCK-8),colony formation,transwell,and wound healing assays.Western blotting and quantitative real-time polymerase chain reaction(qRT-PCR)analyses were performed to detect the interaction between USP25 and the Wnt/β-catenin signaling pathway.The relationship between USP25 and tripartite motif-containing 21(TRIM21)was assessed through mass spectrometry and co-immunoprecipitation(Co-IP)analysis.Finally,we constructed a mouse liver cancer model with the USP25 gene deletion to verify in vivo role of USP25.Results:USP25 was highly expressed in HCC tissue and HCC cell lines.Importantly,high expression of USP25 in tissues was closely related to a poor prognosis.USP25 knockdown markedly reduced the proliferation,migration,and invasion of HepG2 and MHCC97H cells,whereas USP25 overexpression led to the opposite effects.In addition,we demonstrated that USP25 interacts with TRIM21 to regulate the expression of proteins related to epithelial-mesenchymal transition(EMT;E-cadherin,N-cadherin,and Snail)and the Wnt/β-catenin pathway(β-catenin,Adenomatous polyposis coli,Axin2 and Glycogen synthase kinase 3 beta)and those of their downstream proteins(C-myc and Cyclin D1).Finally,we verified that knocking out USP25 inhibited tumor growth and distant metastasis in vivo.Conclusions:In summary,our data showed that USP25 was overexpressed in HCC.USP25 promoted the proliferation,migration,invasion,and EMT of HCC cells by interacting with TRIM21 to activate theβ-catenin signaling pathway.展开更多
基金partially supported by Guangzhou Science and Technology Project[20160701175201707010263]+5 种基金Natural Science Foundation of Guangdong Province[2016A0303130832016A030313420]Team Project of Natural Science Foundation of Guangdong Province[S2013030013315]Fundamental Research Funds for the Central Universities[Grant No.21609317ZX20170413]Guangdong Province Science and Technology Project YUEKEGUICAI[(2015)110-0024]
文摘Objective Osteosarcoma is the most common type of malignant bone tumor in children and adolescents. The role of E3 ligases in tumorigenesis is currently a focus in tumor research. In the present study, we investigated the role of the E3 ligase tripartite motif 21（TRIM21） in osteosarcoma cell proliferation.Methods 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide（MTT） assays were used to assess osteosarcoma cell viability. U2-OS cells stably carrying a recombinant lentivirus expressing tetracycline-regulated TRIM21 were screened. Co-immunoprecipitation was coupled with LCMS/MS analysis to identify novel interacting partners of TRIM21. Co-immunoprecipitation and bimolecular fluorescence complementation（BIFC） were performed to validate the interactions between TRIM21 and its novel partner YWHAZ. A TRIM21-ΔRING construct was generated to test the effects of TRIM21 ligase activity on YWHAZ.Results TRIM21 positively regulated osteosarcoma cell proliferation. Overexpression of TRIM21 enhanced osteosarcoma cell tolerance toward various stresses. YWHAZ protein was identified as a novel interacting partner of TRIM21 and its expression levels were negatively regulated by TRIM21. The RING domain of TRIM21 was required for TRIM21 negative regulation of YWHAZ expression. However,overexpression of YWHAZ did not affect positive regulation of osteosarcoma cell proliferation by TRIM21.Conclusion Our results further clarify the molecular mechanisms underlying the pathogenesis of osteosarcoma.
基金supported by the National Natural Science Foundation of China(22274067,82071187)the Natural Science Foundation of Jiangsu Province(BK20230043)the Fundamental Research Funds for the Central Universities(JUSRP622009)。
文摘Tripartite motif 21(TRIM21)is an E3 ubiquitin ligase that shows great promise for protein degradation through ubiquitination.Here,ultrasmall chiral gold nanoparticles(D-or L-NPs)modified by D-or L-glutathione ligands were fabricated.After conjugated with an NLR family pyrin domain-containing protein 3(NLRP3)antibody(D-NP-a NLRP3 or L-NP-a NLRP3),DNP-a NLRP3 showed effective delivery efficiency of the antibody into microglia and prevented Aβ-mediated microglia senescence,and p16^(ink4a),a marker of senescence,in the microglia was reduced by 90.3%±7.8% while L-NP-a NLRP3 decreased by 48.01%±3.1%.Mechanistic investigations revealed that the D-NP-a NLRP3((1.5±0.3)×10^(7)M^(-1))exhibited sixteen-fold larger binding affinity to transmembrane glycoprotein SLC3A2 than L-type((9.5±2.7)×10^(5)M^(-1)),which led to a high efficiency of antibody delivery and TRIM21-dependent NLRP3 degradation.Notably,the blood-brain barrier(BBB)-crossing ability of chiral NP-a NLRP3 as well as NLRP3 degradation was demonstrated in vivo.The APP/PS1 Alzheimer's disease(AD)model mice experiments exhibited a reduction of 89.7%±6.8% for the NLRP3 protein and 84.2±7.5% for p16^(ink4a)following the intravenous administration of D-NP-a NLRP3 once a week for 60 days.Furthermore,the levels of the AD markers Aβ and phosphorylatedTau in the brains were reduced by 86.2%±8.2% and 81.6%±9.1%;these were 2.1-fold and 1.9-fold higher than those treated with L-NP-a NLRP3,respectively.The studies provide a method to rescue AD-like pathologies and prevent senescence.
基金the National Natural Science Foundation of China(81802996,81871946,and 82072708)Special Foundation for National Science and Technology Basic Research Program of China(2019FY101104)+2 种基金the Program for Development of Innovative Research Team in the First Affiliated Hospital of NJMUthe Priority Academic ProgramDevelopment of JiangsuHigher Education Institutions(JX10231801)Jiangsu Key Medical Discipline(General Surgery)(ZDXKA2016005),Jiangsu Key Lab of Cancer Biomarkers,Prevention and Treatment,Collaborative Innovation Center for Cancer Personalized Medicine,Nanjing Medical University.
文摘Background:Previous studies have revealed the critical role of transglutaminase 2(TGM2)as a potential therapeutic target in cancers,but the oncogenic roles and underlying mechanisms of TGM2 in gastric cancer(GC)are not fully understood.In this study,we examined the role and potential mechanism of TGM2 in GC.Methods:Western blotting,immunohistochemistry,CCK8,colony formation and transwell assays were used to measure TGM2 expression in the GC cells and tissues and to examine the in vitro role of TGM2 in GC.Xenograft and in vivo metastasis experiments were performed to examine the in vivo role of TGM2 in GC.Gene set enrichment analysis,quantitative PCR and western blotting were conducted to screen for potential TGM2 targets involved in GC.Gain/loss-offunction and rescue experiments were conducted to detect the biological roles of STAT1 in GC cells in the context of TGM2.Co-immunoprecipitation,mass spectrometry,quantitative PCR and western blotting were conducted to identify STAT1-interacting proteins and elucidate their regulatory mechanisms.Mutations in TGM2 and two molecules(ZM39923 and A23187)were used to identify the enzymatic activity of TGM2 involved in the malignant progression of GC and elucidate the underlying mechanism.Results:In this study,we demonstrated elevated TGM2 expression in the GC tissues,which closely related to pathological grade,and predicted poor survival in patients with GC.TGM2 overexpression or knockdown promoted(and inhibited)cell proliferation,migration,and invasion,which were reversed by STAT1 knockdown or overexpression.Further studies showed that TGM2 promoted GC progression by inhibiting STAT1 ubiquitination/degradation.Then,tripartite motif-containing protein 21(TRIM21)was identified as a ubiquitin E3 ligase of STAT1 in GC.TGM2 maintained STAT1 stability by facilitating the dissociation of TRIM21 and STAT1 with GTP-binding enzymatic activity.A23187 abolished the role of TGM2 in STAT1 and reversed the pro-tumor role of TGM2 in vitro and in vivo.Conclusions:This study revealed a critical role and regulatory mechanism of TGM2 on STAT1 in GC and highlighted the potential of TGM2 as a therapeutic target,which elucidates the development of medicine or strategies by regulating the GTP-binding activity of TGM2 in GC.
基金National Natural Science Foundation of China(No.81870392)
文摘Background:Hepatocellular carcinoma(HCC)is one of the most common malignant tumors in the world.The ubiquitin-specific peptidase 25(USP25)protein has been reported to participate in the development of several cancers.However,few studies have reported its association with HCC.In this study,we aimed to investigate the function and mechanism of USP25 in the progression of HCC.Methods:We analyzed USP25 protein expression in HCC based on The Cancer Genome Atlas(TCGA)and International Cancer Genome Consortium(ICGC)database cohorts.Then,we constructed USP25-overexpressing and USP25-knockdown HepG2,MHCC97H,and L-O2 cells.We detected the biological function of USP25 by performing a series of assays,such as Cell Counting Kit-8(CCK-8),colony formation,transwell,and wound healing assays.Western blotting and quantitative real-time polymerase chain reaction(qRT-PCR)analyses were performed to detect the interaction between USP25 and the Wnt/β-catenin signaling pathway.The relationship between USP25 and tripartite motif-containing 21(TRIM21)was assessed through mass spectrometry and co-immunoprecipitation(Co-IP)analysis.Finally,we constructed a mouse liver cancer model with the USP25 gene deletion to verify in vivo role of USP25.Results:USP25 was highly expressed in HCC tissue and HCC cell lines.Importantly,high expression of USP25 in tissues was closely related to a poor prognosis.USP25 knockdown markedly reduced the proliferation,migration,and invasion of HepG2 and MHCC97H cells,whereas USP25 overexpression led to the opposite effects.In addition,we demonstrated that USP25 interacts with TRIM21 to regulate the expression of proteins related to epithelial-mesenchymal transition(EMT;E-cadherin,N-cadherin,and Snail)and the Wnt/β-catenin pathway(β-catenin,Adenomatous polyposis coli,Axin2 and Glycogen synthase kinase 3 beta)and those of their downstream proteins(C-myc and Cyclin D1).Finally,we verified that knocking out USP25 inhibited tumor growth and distant metastasis in vivo.Conclusions:In summary,our data showed that USP25 was overexpressed in HCC.USP25 promoted the proliferation,migration,invasion,and EMT of HCC cells by interacting with TRIM21 to activate theβ-catenin signaling pathway.
