Objective:To investigate actinomycin D’s effects on liver cancer progression,explore its underlying mechanisms,focusing on epithelial-mesenchymal transition(EMT)and Wnt/β-catenin signaling,offer new insights and ref...Objective:To investigate actinomycin D’s effects on liver cancer progression,explore its underlying mechanisms,focusing on epithelial-mesenchymal transition(EMT)and Wnt/β-catenin signaling,offer new insights and references for identifying low toxicity traditional Chinese medicine(TCM)monomers with the same targets but lower toxicity or developing compound formulations to enhance pathway blocking effects,and to innovate and develop integrated Chinese and western medicine treatment strategies.Methods:Human liver cancer cells(HepG2)were treated with actinomycin D for in vitro assays.Cell proliferation was assessed via CCK-8,while transwell assays evaluated invasion and migration.Western blot analyzed expression of EMT markers(E-cadherin,β-catenin,Twist1).A nude mouse metastatic model using HepG2 cells was established for in vivo validation,with metastasis efficiency and molecular markers compared between treatment and control groups.Results:Actinomycin D suppressed liver cancer cell proliferation in a dose-dependent and time-dependent manner(CCK-8 assay)and inhibited cell invasion and migration(assessed by transwell assay).Western blot analysis showed that actinomycin D downregulatedβ-catenin and Twist1 while upregulating E-cadherin,indicating suppression of EMT.In vivo experiments demonstrated that actinomycin D significantly reduced metastatic efficiency in mice,consistent with decreasedβ-catenin/Twist1 expression and increased E-cadherin levels in tumor tissues.Conclusions:Actinomycin D suppresses liver cancer invasion and metastasis by inhibiting theWnt/β-catenin pathway and EMTprogression.These findings highlight its dual antitumor role in both proliferation inhibition and metastasis suppression,providing mechanistic insights for its clinical applications.展开更多
OBJECTIVE Low dose of actinomycin D(LDAct D)was reported as a potent P53 activator and protected normal proliferating cells during anti-mitotic chemotherapy.However,the mechanism of LDAct D on P53 activation is still ...OBJECTIVE Low dose of actinomycin D(LDAct D)was reported as a potent P53 activator and protected normal proliferating cells during anti-mitotic chemotherapy.However,the mechanism of LDAct D on P53 activation is still undetermined.In this study,the mechanism of LDAct D on the synergistic antitumor effect for cisplatin(CDDP)and P53 reactivation in KB cells was studied in detail.METHODS Cell viability was determined by MTT and LDH release.Apoptosis was determined by AnnexinⅤ-FITC/PI staining.Mitochondrial membrane potential(MMP)was detected by JC-1 stain-ing.Expression of P53,PARP,BAX,BCL-XL,PUMA,MDM2 and MDMX was detected by Western blotting(WB)and/or immunofluorescence(IF).P53-MDM2 complex was detected by ELISA.Molecular docking of receptor MDM2 and MDMX with actinomycin D(ACTD)was analyzed by Discovery Studio.RESULTS Compared with CDDP alone,P53 expression and the cytotoxicity on KB cells was significantly increased by the combination therapy.P53 regulatory proteins were increased while MMP was decreased.Meanwhile,knockdown of PUMA(P53 upregulated modulator of apoptosis)efficiently blocked the synergistic effect of LDAct D to CDDP.P53 activation was found to be accompanied with the increase of MDMX but not MDM2.Meanwhile,MDM2-P53 complex in KB cells was significantly decreased by LDAct D.Docking of both receptor MDM2 and MDMX with ACTD exhibited well established bonds with nearby amino acid residues.CONCLUSION LDAct D was probably an inhibitor of both MDM2 and MDMX.The synergistic effects of LDAct D for CDDP on KB cells depended on its effect on reactivating P53 and PUMA mediated mitochondrial apoptosis.展开更多
Aim To study the synergistic effect and mechanism of actinomycin D to the anti-cancer activity of cispl- atin on KB cells. Methods Cytotoxicity of actinomycin D on KB cells was evaluated by MTT and LDH Assay. Apoptosi...Aim To study the synergistic effect and mechanism of actinomycin D to the anti-cancer activity of cispl- atin on KB cells. Methods Cytotoxicity of actinomycin D on KB cells was evaluated by MTT and LDH Assay. Apoptosis was detected by Flow cytometry （FCM）. Expression of p53, PUMA, Bax, Bcl-2 and Bcl-xl was detected by WB （Western blot） or IF （immunofluorescence staining）. The translocation of PUMA, Bax, Bcl-2 and Bcl-xl was detected by confocal microscope. PUMA knockdown was achieved by PUMA siRNA. Results Actinomycin D synergistically enhanced the cytotoxicity of cisplatin on KB cells. Time-dependent increasing of PUMA and p53 in- duced by actinomycin D was accompanied by the translocation of PUMA and Bax/Bcl-xl in KB cells. Knockdown of PUMA effectively blocked the synergistic effect of actinomycin D to cisplatin. Conclusion Actinomycin D effi- ciently enhanced the anti-cancer activity of cisplatin on KB cells. Up-regulation of PUMA by actinomycin D is like- ly responsible for the observed synergistic effect between the two drugs. Combination of actinomycin D and cisplatin may lead to an effective cancer treatment strategy.展开更多
Natural product biosynthesis is controlled at multiple levels.Characterization of naturally occurring promoters has facilitated the study of the synthetic biology of natural products.Herein,we report the discovery of ...Natural product biosynthesis is controlled at multiple levels.Characterization of naturally occurring promoters has facilitated the study of the synthetic biology of natural products.Herein,we report the discovery of two highyield actinomycin D(ActD)-producing streptomycetes and the identification of a strong bidirectional acmN2p promoter from the ActD gene clusters and its application in heterologous expression of three core genes involved in the bacterial alkaloid bohemamine biosynthesis,providing a good example for identification of new promoters for synthetic biological applications.展开更多
Actinomycin D (AMD) is an anticancer antibiotic that can bind selectively to both double-stranded and single-stranded DNA, and this binding greatly enhances DNA photosensitization. Using electron paramagnetic resonanc...Actinomycin D (AMD) is an anticancer antibiotic that can bind selectively to both double-stranded and single-stranded DNA, and this binding greatly enhances DNA photosensitization. Using electron paramagnetic resonance (EPR) in combination with spin trapping techniques, a systematic study was carried out on the reactive oxygen species generated in the photosensitization process of AMD. It was found that 1O2 and $O_2^{ - \cdot } $ are important reactive intermediates either in solution or in DNA complexes, and the generation of these species is in competition. This finding suggests that the photodynamic action of AMD proceeds via two pathways: energy transfer (type I mechanism) and electron transfer (type II mechanism). 1O2 is the main product formed via energy transfer reaction in solution while electron transfer between the excited states of AMD and DNA becomes the predominant pathway in DNA complexes.展开更多
基金supported by the Heilongjiang Province College Student Innovation and Entrepreneurship Training Program(No.202310222032).
文摘Objective:To investigate actinomycin D’s effects on liver cancer progression,explore its underlying mechanisms,focusing on epithelial-mesenchymal transition(EMT)and Wnt/β-catenin signaling,offer new insights and references for identifying low toxicity traditional Chinese medicine(TCM)monomers with the same targets but lower toxicity or developing compound formulations to enhance pathway blocking effects,and to innovate and develop integrated Chinese and western medicine treatment strategies.Methods:Human liver cancer cells(HepG2)were treated with actinomycin D for in vitro assays.Cell proliferation was assessed via CCK-8,while transwell assays evaluated invasion and migration.Western blot analyzed expression of EMT markers(E-cadherin,β-catenin,Twist1).A nude mouse metastatic model using HepG2 cells was established for in vivo validation,with metastasis efficiency and molecular markers compared between treatment and control groups.Results:Actinomycin D suppressed liver cancer cell proliferation in a dose-dependent and time-dependent manner(CCK-8 assay)and inhibited cell invasion and migration(assessed by transwell assay).Western blot analysis showed that actinomycin D downregulatedβ-catenin and Twist1 while upregulating E-cadherin,indicating suppression of EMT.In vivo experiments demonstrated that actinomycin D significantly reduced metastatic efficiency in mice,consistent with decreasedβ-catenin/Twist1 expression and increased E-cadherin levels in tumor tissues.Conclusions:Actinomycin D suppresses liver cancer invasion and metastasis by inhibiting theWnt/β-catenin pathway and EMTprogression.These findings highlight its dual antitumor role in both proliferation inhibition and metastasis suppression,providing mechanistic insights for its clinical applications.
基金The project supported by Ministry of Science and Technology Project of International Cooperation(2011DFR31240)National Science and Technology Major Projects″Major Drug Discovery(″2012ZX09301002001001)
文摘OBJECTIVE Low dose of actinomycin D(LDAct D)was reported as a potent P53 activator and protected normal proliferating cells during anti-mitotic chemotherapy.However,the mechanism of LDAct D on P53 activation is still undetermined.In this study,the mechanism of LDAct D on the synergistic antitumor effect for cisplatin(CDDP)and P53 reactivation in KB cells was studied in detail.METHODS Cell viability was determined by MTT and LDH release.Apoptosis was determined by AnnexinⅤ-FITC/PI staining.Mitochondrial membrane potential(MMP)was detected by JC-1 stain-ing.Expression of P53,PARP,BAX,BCL-XL,PUMA,MDM2 and MDMX was detected by Western blotting(WB)and/or immunofluorescence(IF).P53-MDM2 complex was detected by ELISA.Molecular docking of receptor MDM2 and MDMX with actinomycin D(ACTD)was analyzed by Discovery Studio.RESULTS Compared with CDDP alone,P53 expression and the cytotoxicity on KB cells was significantly increased by the combination therapy.P53 regulatory proteins were increased while MMP was decreased.Meanwhile,knockdown of PUMA(P53 upregulated modulator of apoptosis)efficiently blocked the synergistic effect of LDAct D to CDDP.P53 activation was found to be accompanied with the increase of MDMX but not MDM2.Meanwhile,MDM2-P53 complex in KB cells was significantly decreased by LDAct D.Docking of both receptor MDM2 and MDMX with ACTD exhibited well established bonds with nearby amino acid residues.CONCLUSION LDAct D was probably an inhibitor of both MDM2 and MDMX.The synergistic effects of LDAct D for CDDP on KB cells depended on its effect on reactivating P53 and PUMA mediated mitochondrial apoptosis.
文摘Aim To study the synergistic effect and mechanism of actinomycin D to the anti-cancer activity of cispl- atin on KB cells. Methods Cytotoxicity of actinomycin D on KB cells was evaluated by MTT and LDH Assay. Apoptosis was detected by Flow cytometry （FCM）. Expression of p53, PUMA, Bax, Bcl-2 and Bcl-xl was detected by WB （Western blot） or IF （immunofluorescence staining）. The translocation of PUMA, Bax, Bcl-2 and Bcl-xl was detected by confocal microscope. PUMA knockdown was achieved by PUMA siRNA. Results Actinomycin D synergistically enhanced the cytotoxicity of cisplatin on KB cells. Time-dependent increasing of PUMA and p53 in- duced by actinomycin D was accompanied by the translocation of PUMA and Bax/Bcl-xl in KB cells. Knockdown of PUMA effectively blocked the synergistic effect of actinomycin D to cisplatin. Conclusion Actinomycin D effi- ciently enhanced the anti-cancer activity of cisplatin on KB cells. Up-regulation of PUMA by actinomycin D is like- ly responsible for the observed synergistic effect between the two drugs. Combination of actinomycin D and cisplatin may lead to an effective cancer treatment strategy.
基金supported in parts by National Natural Science Foundation of China grants(82173688 and 82373772)The science and technology innovation Program of Hunan Province(2021RC4067)+2 种基金a research fund from Institute of Health and Medicine(IHM),Hefei Comprehensive National Science Center(to Y.H.)the Chinese Ministry of Education 111 Project(BP0820034)(to Y.D.)the Fundamental Research Funds for the Central Universities of Central South University 2020zzts247(to D.T.).
文摘Natural product biosynthesis is controlled at multiple levels.Characterization of naturally occurring promoters has facilitated the study of the synthetic biology of natural products.Herein,we report the discovery of two highyield actinomycin D(ActD)-producing streptomycetes and the identification of a strong bidirectional acmN2p promoter from the ActD gene clusters and its application in heterologous expression of three core genes involved in the bacterial alkaloid bohemamine biosynthesis,providing a good example for identification of new promoters for synthetic biological applications.
文摘Actinomycin D (AMD) is an anticancer antibiotic that can bind selectively to both double-stranded and single-stranded DNA, and this binding greatly enhances DNA photosensitization. Using electron paramagnetic resonance (EPR) in combination with spin trapping techniques, a systematic study was carried out on the reactive oxygen species generated in the photosensitization process of AMD. It was found that 1O2 and $O_2^{ - \cdot } $ are important reactive intermediates either in solution or in DNA complexes, and the generation of these species is in competition. This finding suggests that the photodynamic action of AMD proceeds via two pathways: energy transfer (type I mechanism) and electron transfer (type II mechanism). 1O2 is the main product formed via energy transfer reaction in solution while electron transfer between the excited states of AMD and DNA becomes the predominant pathway in DNA complexes.
