1
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Bär SI, Gold M, Schleser SW, Rehm T, Bär A, Köhler L, Carnell LR, Biersack B, Schobert R. Guided Antitumoural Drugs: (Imidazol-2-ylidene)(L)gold(I) Complexes Seeking Cellular Targets Controlled by the Nature of Ligand L. Chemistry 2021; 27:5003-5010. [PMID: 33369765 PMCID: PMC7986617 DOI: 10.1002/chem.202005451] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Indexed: 01/21/2023]
Abstract
Three [1,3-diethyl-4-(p-methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)imidazol-2-ylidene](L)gold(I) complexes, 4 a (L=Cl), 5 a (L=PPh3 ), and 6 a (L=same N-heterocyclic carbene (NHC)), and their fluorescent [4-(anthracen-9-yl)-1,3-diethyl-5-phenylimidazol-2-ylidene](L)gold(I) analogues, 4 b, 5 b, and 6 b, respectively, were studied for their localisation and effects in cancer cells. Despite their identical NHC ligands, the last three accumulated in different compartments of melanoma cells, namely, the nucleus (4 b), mitochondria (5 b), or lysosomes (6 b). Ligand L was also more decisive for the site of accumulation than the NHC ligand because the couples 4 a/4 b, 5 a/5 b, and 6 a/6 b, carrying different NHC ligands, afforded similar results in cytotoxicity tests, and tests on targets typically found at their sites of accumulation, such as DNA in nuclei, reactive oxygen species and thioredoxin reductase in mitochondria, and lysosomal membranes. Regardless of the site of accumulation, cancer cell apoptosis was eventually induced. The concept of guiding a bioactive complex fragment to a particular subcellular target by secondary ligand L could reduce unwanted side effects.
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Affiliation(s)
- Sofia I. Bär
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Madeleine Gold
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Sebastian W. Schleser
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Tobias Rehm
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Alexander Bär
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Leonhard Köhler
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Lucas R. Carnell
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Bernhard Biersack
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
| | - Rainer Schobert
- Organic Chemistry LaboratoryUniversity BayreuthUniversitaetsstr. 3095447BayreuthGermany
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2
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Lettl C, Schindele F, Testolin G, Bär A, Rehm T, Brönstrup M, Schobert R, Bilitewski U, Haas R, Fischer W. Inhibition of Type IV Secretion Activity and Growth of Helicobacter pylori by Cisplatin and Other Platinum Complexes. Front Cell Infect Microbiol 2020; 10:602958. [PMID: 33392108 PMCID: PMC7775389 DOI: 10.3389/fcimb.2020.602958] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/17/2020] [Indexed: 12/20/2022] Open
Abstract
Type IV secretion systems are protein secretion machineries that are frequently used by pathogenic bacteria to inject their virulence factors into target cells of their respective hosts. In the case of the human gastric pathogen Helicobacter pylori, the cytotoxin-associated gene (Cag) type IV secretion system is considered a major cause for severe disease, such as gastric cancer, and thus constitutes an attractive target for specific treatment options against H. pylori infections. Here, we have used a Cag type IV secretion reporter assay for screening a repurposing compound library for inhibitors targeting this system. We found that the antitumor agent cisplatin, a platinum coordination complex that kills target cells by formation of DNA crosslinks, is a potent inhibitor of the Cag type IV secretion system. Strikingly, we found that this inhibitory activity of cisplatin depends on a ligand exchange reaction which incorporates a solvent molecule (dimethylsulfoxide) into the complex, a modification which is known to be deleterious for DNA crosslinking, and for its anticancer activity. We extended our analysis to several analogous platinum complexes containing N-heterocyclic carbene, as well as DMSO or other ligands, and found varying inhibitory activities toward the Cag system which were not congruent with their DNA-binding properties, suggesting that protein interactions may cause the inhibitory effect. Inhibition experiments under varying conditions revealed effects on adherence and bacterial viability as well, and showed that the type IV secretion-inhibitory capacity of platinum complexes can be inactivated by sulfur-containing reagents and in complex bacterial growth media. Taken together, our results demonstrate DNA binding-independent inhibitory effects of cisplatin and other platinum complexes against different H. pylori processes including type IV secretion.
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Affiliation(s)
- Clara Lettl
- Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Faculty of Medicine, LMU Munich, Munich, Germany.,German Center for Infection Research (DZIF), Munich Site, Munich, Germany
| | - Franziska Schindele
- Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Faculty of Medicine, LMU Munich, Munich, Germany.,German Center for Infection Research (DZIF), Munich Site, Munich, Germany
| | - Giambattista Testolin
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,German Center for Infection Research (DZIF), Hannover-Braunschweig Site, Braunschweig, Germany
| | - Alexander Bär
- Organic Chemistry Laboratory, University Bayreuth, Bayreuth, Germany
| | - Tobias Rehm
- Organic Chemistry Laboratory, University Bayreuth, Bayreuth, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,German Center for Infection Research (DZIF), Hannover-Braunschweig Site, Braunschweig, Germany
| | - Rainer Schobert
- Organic Chemistry Laboratory, University Bayreuth, Bayreuth, Germany
| | - Ursula Bilitewski
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,German Center for Infection Research (DZIF), Hannover-Braunschweig Site, Braunschweig, Germany
| | - Rainer Haas
- Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Faculty of Medicine, LMU Munich, Munich, Germany.,German Center for Infection Research (DZIF), Munich Site, Munich, Germany
| | - Wolfgang Fischer
- Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Faculty of Medicine, LMU Munich, Munich, Germany.,German Center for Infection Research (DZIF), Munich Site, Munich, Germany
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Rothemund M, Bär SI, Rehm T, Kostrhunova H, Brabec V, Schobert R. Antitumoral effects of mitochondria-targeting neutral and cationic cis-[bis(1,3-dibenzylimidazol-2-ylidene)Cl(L)]Pt(ii) complexes. Dalton Trans 2020; 49:8901-8910. [DOI: 10.1039/d0dt01664k] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
cis-[Bis(1,3-dibenzylimidazol-2-ylidene)PtIICl(L)] complexes target mitochondria regardless of charge and size of ligands L, yet show different anticancer effects.
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Affiliation(s)
| | - Sofia I. Bär
- Organic Chemistry Laboratory
- University of Bayreuth
- 95440 Bayreuth
- Germany
| | - Tobias Rehm
- Organic Chemistry Laboratory
- University of Bayreuth
- 95440 Bayreuth
- Germany
| | - Hana Kostrhunova
- Czech Academy of Sciences
- Institute of Biophysics
- CZ-61265
- Czech Republic
| | - Viktor Brabec
- Czech Academy of Sciences
- Institute of Biophysics
- CZ-61265
- Czech Republic
| | - Rainer Schobert
- Organic Chemistry Laboratory
- University of Bayreuth
- 95440 Bayreuth
- Germany
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4
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Rehm T, Rothemund M, Dietel T, Kempe R, Schobert R. Synthesis, structures and cytotoxic effects in vitro of cis- and trans-[Pt IVCl 4(NHC) 2] complexes and their Pt II precursors. Dalton Trans 2019; 48:16358-16365. [PMID: 31624819 DOI: 10.1039/c9dt02438g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Four new bis(N,N-dialkylbenzimidazol-2-ylidene)dichlorido platinum(ii) complexes 2 featuring N-alkyl substituents of increasing size (a: Me, b: Et, c: n-butyl, d: n-octyl) were synthesised and oxidised with PhICl2 to give the corresponding [PtIVCl4(N,N-dialkylbenzimidazol-2-ylidene)2] complexes 4 as potential anticancer prodrugs. The known bis(N,N-dibenzylimidazol-2-ylidene)dichlorido platinum(ii) complex 1 was likewise oxidised to [PtIVCl4(N,N-dibenzylimidazol-2-ylidene)2] 3. In contrast, oxidation of complexes 1 and 2 with H2O2 or hypochlorites, or exchange of chlorido for hydroxo ligands in tetrachlorido complexes 4 failed to give isolable complexes of type [PtIVCl4-n(OH)n(NHC)2]. In MTT assays the [PtIICl2(NHC)2]/[PtIVCl4(NHC)2] complex couples 1/3, 2c/4c, and trans-2c/trans-4c, bearing either N-benzyl or N-butyl substituents, each showed similar single-digit micromolar IC50 values against at least three out of five human cancer cell lines, presumably due to an intracellular reduction of the PtIV complexes to their active PtII congeners. Unlike cisplatin, whose anticancer effect requires functional p53, each of them was active both in wildtype and in p53-negative HCT116 colon carcinoma cells. In ethidium bromide saturation assays with isolated DNA, cis-(bis-NHC)PtII complexes such as 1 caused morphological DNA changes more pronounced than those initiated by cisplatin, while the corresponding cis-(bis-NHC)PtIV complexes such as 3 interacted with DNA in a less structure-modifying way.
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Affiliation(s)
- Tobias Rehm
- Organic Chemistry Laboratory, University Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth, Germany.
| | - Matthias Rothemund
- Organic Chemistry Laboratory, University Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth, Germany.
| | - Thomas Dietel
- Lehrstuhl fuer Anorganische Chemie II, University Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth, Germany
| | - Rhett Kempe
- Lehrstuhl fuer Anorganische Chemie II, University Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth, Germany
| | - Rainer Schobert
- Organic Chemistry Laboratory, University Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth, Germany.
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5
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Rehm T, Rothemund M, Bär A, Dietel T, Kempe R, Kostrhunova H, Brabec V, Kasparkova J, Schobert R. N,N-Dialkylbenzimidazol-2-ylidene platinum complexes – effects of alkyl residues and ancillary cis-ligands on anticancer activity. Dalton Trans 2018; 47:17367-17381. [DOI: 10.1039/c8dt03360a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Benzimidazol-2-ylidene platinum complexes exhibit anticancer activity, which is tuneable via N-alkyl residues and ancillary ligands and is different from that of cisplatin.
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Affiliation(s)
- Tobias Rehm
- Department of Chemistry
- University Bayreuth
- 95440 Bayreuth
- Germany
| | | | - Alexander Bär
- Department of Chemistry
- University Bayreuth
- 95440 Bayreuth
- Germany
| | - Thomas Dietel
- Lehrstuhl fuer Anorganische Chemie II
- University Bayreuth
- 95440 Bayreuth
- Germany
| | - Rhett Kempe
- Lehrstuhl fuer Anorganische Chemie II
- University Bayreuth
- 95440 Bayreuth
- Germany
| | - Hana Kostrhunova
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- CZ-61265 Brno
- Czech Republic
| | - Viktor Brabec
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- CZ-61265 Brno
- Czech Republic
| | - Jana Kasparkova
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- CZ-61265 Brno
- Czech Republic
| | - Rainer Schobert
- Department of Chemistry
- University Bayreuth
- 95440 Bayreuth
- Germany
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6
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Draut H, Rehm T, Begemann G, Schobert R. Antiangiogenic and Toxic Effects of Genistein, Usnic Acid, and Their Copper Complexes in Zebrafish Embryos at Different Developmental Stages. Chem Biodivers 2017; 14. [PMID: 27936296 DOI: 10.1002/cbdv.201600302] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 11/18/2016] [Indexed: 02/01/2023]
Abstract
Angiogenesis plays a major role in the normal embryonic development and in diseases such as cancer. Drugs that control angiogenesis are an alternative way to tackle this disease. The polyphenols usnic acid (3), genistein (5), and daidzein (6) were tested for antiangiogenic and unwanted effects in zebrafish embryos whose blood vessel system resembles that of mammals. The established tyrosine kinase inhibitors axitinib (1) and tyrphostin AG490 (2) were included for comparison. All compounds except 6 caused distinct antiangiogenic effects such as a concentration-dependent reduction of intersegmental vessels, dorsal longitudinal anastomotic vessels, subintestinal veins and secondary sprouts. As side effects, pericardial oedema and the impairment of blood flow were observed. Usnic acid (3), genistein (5) and Cu(II)-genisteinate (7) gave rise to a curvature of the spine. Compounds 5 and 7 also induced cell death in the head of the embryos at higher doses. All effects were more pronounced when the compounds had been applied at an early stage (24 hpf) rather than at 48 hpf. The copper complexes 4 and 7 showed a stronger antiangiogenic effect than the free ligands 3 and 5. The genistein complex 7 was antiangiogenic at doses so low that side effects were tolerable, and thus it may be a potential anticancer drug candidate.
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Affiliation(s)
- Heidrun Draut
- Organic Chemistry, University Bayreuth, Universitätsstrasse 30, NW 1, 95447, Bayreuth, Germany.,Developmental Biology, University Bayreuth, Universitätsstrasse 30, 95440, Bayreuth, Germany
| | - Tobias Rehm
- Organic Chemistry, University Bayreuth, Universitätsstrasse 30, NW 1, 95447, Bayreuth, Germany
| | - Gerrit Begemann
- Developmental Biology, University Bayreuth, Universitätsstrasse 30, 95440, Bayreuth, Germany
| | - Rainer Schobert
- Organic Chemistry, University Bayreuth, Universitätsstrasse 30, NW 1, 95447, Bayreuth, Germany
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7
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Muenzner JK, Biersack B, Albrecht A, Rehm T, Lacher U, Milius W, Casini A, Zhang JJ, Ott I, Brabec V, Stuchlikova O, Andronache IC, Kaps L, Schuppan D, Schobert R. Ferrocenyl-Coupled N-Heterocyclic Carbene Complexes of Gold(I): A Successful Approach to Multinuclear Anticancer Drugs. Chemistry 2016; 22:18953-18962. [PMID: 27761940 DOI: 10.1002/chem.201604246] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Julienne K. Muenzner
- Organic Chemistry Laboratory; University Bayreuth; Universitätsstrasse 30 95447 Bayreuth Germany
| | - Bernhard Biersack
- Organic Chemistry Laboratory; University Bayreuth; Universitätsstrasse 30 95447 Bayreuth Germany
| | - Alexander Albrecht
- Organic Chemistry Laboratory; University Bayreuth; Universitätsstrasse 30 95447 Bayreuth Germany
| | - Tobias Rehm
- Organic Chemistry Laboratory; University Bayreuth; Universitätsstrasse 30 95447 Bayreuth Germany
| | - Ulrike Lacher
- Organic Chemistry Laboratory; University Bayreuth; Universitätsstrasse 30 95447 Bayreuth Germany
| | - Wolfgang Milius
- Lehrstuhl für Anorganische Chemie I; Universität Bayreuth; Universitätsstrasse 30 95447 Bayreuth Germany
| | - Angela Casini
- Department of Pharmacokinetics, Toxicology, and Targeting; University of Groningen; Antonius Deusinglaan 1 9713 Groningen The Netherlands
- School of Chemistry; Cardiff University, Main Building; CF10 3AT Cardiff UK
| | - Jing-Jing Zhang
- Medicinal and Pharmaceutical Chemistry; Technische Universität Braunschweig; Beethovenstrasse 55 38106 Braunschweig Germany
| | - Ingo Ott
- Medicinal and Pharmaceutical Chemistry; Technische Universität Braunschweig; Beethovenstrasse 55 38106 Braunschweig Germany
| | - Viktor Brabec
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Kralovopolska 135 61265 Brno Czech Republic
- Department of Biophysics; Faculty of Science; Palacky University; Listopadu 12 77146 Olomouc Czech Republic
| | - Olga Stuchlikova
- Institute of Biophysics; Academy of Sciences of the Czech Republic; Kralovopolska 135 61265 Brno Czech Republic
- Department of Biophysics; Faculty of Science; Palacky University; Listopadu 12 77146 Olomouc Czech Republic
| | - Ion C. Andronache
- Research Centre for Integrated Analysis and Territorial Management; University of Bucharest; 1 Nicolae Balcescu bvd., District 1 010055 Bucharest Romania
| | - Leonard Kaps
- Institute of Translational Immunology; University Medical Center of the Johannes Gutenberg University; Langenbeckstrasse 1 55131 Mainz Germany
| | - Detlef Schuppan
- Institute of Translational Immunology; University Medical Center of the Johannes Gutenberg University; Langenbeckstrasse 1 55131 Mainz Germany
- Division of Gastroenterology; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston USA
| | - Rainer Schobert
- Organic Chemistry Laboratory; University Bayreuth; Universitätsstrasse 30 95447 Bayreuth Germany
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8
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Schmitt F, Donnelly K, Muenzner JK, Rehm T, Novohradsky V, Brabec V, Kasparkova J, Albrecht M, Schobert R, Mueller T. Effects of histidin-2-ylidene vs. imidazol-2-ylidene ligands on the anticancer and antivascular activity of complexes of ruthenium, iridium, platinum, and gold. J Inorg Biochem 2016; 163:221-228. [PMID: 27491634 DOI: 10.1016/j.jinorgbio.2016.07.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/16/2016] [Accepted: 07/26/2016] [Indexed: 10/21/2022]
Abstract
Couples of N-heterocyclic carbene complexes of ruthenium, iridium, platinum, and gold, each differing only in the carbene ligand being either 1,3-dimethylimidazol-2-ylidene (IM) or 1,3-dimethyl-N-boc-O-methylhistidin-2-ylidene (HIS), were assessed for their antiproliferative effect on seven cancer cell lines, their interaction with DNA, their cell cycle interference, and their vascular disrupting properties. In MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays only the platinum complexes were cytotoxic at single-digit micromolar IC50 concentrations with the (HIS)Pt complex being on average twice as active as the (IM)Pt complex. The former was highly efficacious against cisplatin-resistant HT-29 colon carcinoma cells where the latter had no effect. Both Pt complexes were accumulated by cancer cells and bound to double-helical DNA equally well. Only the (HIS)Pt complex modified the electrophoretic mobility of circular DNA in vitro due to the HIS ligand causing greater morphological changes to the DNA. Both platinum complexes induced accumulation of 518A2 melanoma cells in G2/M and S phase of the cell cycle. A disruption of blood vessels in the chorioallantoic membrane of fertilized chicken eggs was observed for both platinum complexes and the (IM)gold complex. The (HIS)platinum complex was as active as cisplatin in tumor xenografted mice while being tolerated better. We found that the HIS ligand may augment the cytotoxicity of certain antitumoral metal fragments in two ways: by acting as a transmembrane carrier increasing the cellular accumulation of the complex, and by initiating a pronounced distortion and unwinding of DNA. We identified a new (HIS)platinum complex which was highly cytotoxic against cancer cells including cisplatin-resistant ones.
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Affiliation(s)
- Florian Schmitt
- Organic Chemistry Laboratory, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Kate Donnelly
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Julienne K Muenzner
- Organic Chemistry Laboratory, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Tobias Rehm
- Organic Chemistry Laboratory, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Vojtech Novohradsky
- Institute of Biophysics, Academy of Sciences of the Czech Republic, CZ-61265 Brno, Czech Republic
| | - Viktor Brabec
- Institute of Biophysics, Academy of Sciences of the Czech Republic, CZ-61265 Brno, Czech Republic
| | - Jana Kasparkova
- Department of Biophysics, Faculty of Science, Palacky University, 17. listopadu 12, CZ-77146 Olomouc, Czech Republic
| | - Martin Albrecht
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Rainer Schobert
- Organic Chemistry Laboratory, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
| | - Thomas Mueller
- Department of Internal Medicine IV, Oncology/Hematology, Martin-Luther-University Halle-Wittenberg, 06120 Halle-Saale, Germany
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9
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Rehm T, Rothemund M, Muenzner JK, Noor A, Kempe R, Schobert R. Novel cis-[(NHC)1(NHC)2(L)Cl]platinum(ii) complexes – synthesis, structures, and anticancer activities. Dalton Trans 2016; 45:15390-15398. [DOI: 10.1039/c6dt02350a] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Platinum(ii) complexes bearing two different, cis-oriented, N-heterocyclic carbene ligands are readily accessible for catalysis or as selective, pleiotropic anticancer agents.
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Affiliation(s)
- Tobias Rehm
- Organic Chemistry Laboratory
- University Bayreuth
- 95440 Bayreuth
- Germany
| | | | | | - Awal Noor
- Lehrstuhl fuer Anorganische Chemie II (Catalyst Design)
- University Bayreuth
- 95440 Bayreuth
- Germany
| | - Rhett Kempe
- Lehrstuhl fuer Anorganische Chemie II (Catalyst Design)
- University Bayreuth
- 95440 Bayreuth
- Germany
| | - Rainer Schobert
- Organic Chemistry Laboratory
- University Bayreuth
- 95440 Bayreuth
- Germany
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10
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Muenzner JK, Rehm T, Biersack B, Casini A, de Graaf IAM, Worawutputtapong P, Noor A, Kempe R, Brabec V, Kasparkova J, Schobert R. Adjusting the DNA Interaction and Anticancer Activity of Pt(II) N-Heterocyclic Carbene Complexes by Steric Shielding of the Trans Leaving Group. J Med Chem 2015; 58:6283-92. [DOI: 10.1021/acs.jmedchem.5b00896] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
| | | | | | - Angela Casini
- Department
of Pharmacokinetics, Toxicology and Targeting, Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Inge A. M. de Graaf
- Department
of Pharmacokinetics, Toxicology and Targeting, Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Pawida Worawutputtapong
- Department
of Pharmacokinetics, Toxicology and Targeting, Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | | | | | - Viktor Brabec
- Institute
of Biophysics, Academy of Sciences of the Czech Republic, CZ-61265 Brno, Czech Republic
| | - Jana Kasparkova
- Department
of Biophysics, Faculty of Science, Palacky University, 17. listopadu
12, CZ-77146 Olomouc, Czech Republic
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12
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Höltig D, Hennig-Pauka I, Thies K, Rehm T, Beyerbach M, Gerlach GF, Waldmann KH. Porcine Pleuropneumonie: genetisch bedingt? Pneumologie 2010. [DOI: 10.1055/s-0030-1251451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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13
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Höltig D, Hennig-Pauka I, Beyerbach M, Thies K, Rehm T, Gerlach GF, Waldmann KH. [Comparison of the diagnostic significance of clinical, radiographic and ultrasonographic results after an experimental aerosol infection of pigs with Actinobacillus pleuropneumoniae]. Berl Munch Tierarztl Wochenschr 2008; 121:422-431. [PMID: 19086692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Scoring schemes for clinical, ultrasonographic and radiographic findings in pigs were developed based upon a standardized animal model for Actinobacillus pleuropneumoniae infection.The results of these methods were compared to each other as well as with the corresponding pathomorphological findings during necropsy. Altogether 69 pigs of different breeding lines (Hampshire, Pietrain and German Landrace were examined. Positive correlations were found between the results of all three methods as well as with the necropsy scores (p <0.0001). Different pathomorphological findings were detected either by radiographic or by ultrasonographic examination dependent upon the type of lung tissue alterations: Alterations of the pleura as well as sequestration of lung tissue on the lung surface could be clearly identified during the ultrasonographic examination while deep tissue alterations with no contact to the lung surface could be detected reliably by radiographic examination. Both methods complement each other, and the application of a combined ultrasonographic and radiographic examination of the thorax allows a comprehensive inspection of the lung condition. Particularly during the acute phase of the disease the extent of lung tissue damage can be estimated more precisely than by clinical examination alone.
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Affiliation(s)
- D Höltig
- Klinik für Kleine Klauentiere und Forensische Medizin und Ambulatorische Klinik, Stiftung Tierärztliche Hochschule Hannover.
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Maaß S, Lutz E, Metz F, Rehm T, Kraume M. Experimentelle und numerische Untersuchungen von gerührten Flüssig/Flüssig-Systemen für die PVC-Produktion mit mehrstufigen Rührern. CHEM-ING-TECH 2008. [DOI: 10.1002/cite.200890077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Rehm T, Benga L, Danilowicz E, Drungowski M, Hoeltig D, Kahlisch D, Oehlmann W, Probst I, Gerlach GF. [Functional genome analysis investigating resistance to respiratory tract disease in a porcine Actinobacillus pleuropneumoniae infection model]. Dtsch Tierarztl Wochenschr 2008; 115:260-264. [PMID: 18672736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Here we present the work of the multidisciplinary consortium IRAS (Development of Genetic Markers for Immune Defence and Resistance in the Porcine Respiratory Tract) which includes different commercial and research institutions and was formed as a response to the call "Functional Genome Analysis in the Animal Organism (FUGATO)" by the German Ministry of Education and Research. IRAS started work in the fall of 2005 and--using the experimental infection of pigs with Actinobacillus pleuropneumoniae as model pathogen--aims at i) characterizing the course of infection by clinical as well as advanced laboratory tools (phenotypic-genetic approach) and ii) defining the diversity and distribution of allels known to be associated with immune defence in mouse and man (homolog-genetic approach). The intention is to identify genetic markers for increased resistance to infection thereby providing additional tools for the estimation of breeding values to the pig industry.
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Affiliation(s)
- T Rehm
- Zentrum für Infektionsmedizin, Institut für Mikrobiologie der Stiftung Tierärztliche Hochschule Hannover
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Beyerbach M, Rehm T, Kreienbrock L, Gerlach GF. [Eradication of paratuberculosis in dairy herds: determination of the initial herd prevalence and modelling of prevalence development]. Dtsch Tierarztl Wochenschr 2001; 108:291-6. [PMID: 11505846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
A prerequisite for the success of any eradication programme is the accurate determination of the initial herd prevalence as well as a herd-specific prediction of prevalence development. This prerequisite is not currently given for the eradication of paratuberculosis in infected herds. In the work presented a method to predict the initial paratuberculosis prevalence in infected herds is presented; it is based on the formation of two groups (ELISA-positive and negative) and the determination of generally applicable factors (positive predictive value [ppvn] of the ELISA and sensitivity of fecal culture in the ELISA-negative group [senF]). The ppvn of the ELISA was determined to be 0.6 based on the cultural examination of the ileocaecal lymph node of 64 ELISA-positive animals; the value for senF was set to be 0.64 based on the cultural examination of feces and ileocaecal lymph nodes of 40 ELISA-negative animals. To calculate the initial herd prevalence the number of animals in each of the groups was multiplied with the ppvn of the ELISA or with the reciprocal value of senF (1.5). The values were added and divided by the size of the herd. The practicability of this model was examined on nine herds with a total of 708 animals. The development of herd prevalence was modelled based on the examination scheme given in the paratuberculosis control programme of the "Niedersächsische Tierseuchenkasse" (local board for infectious disease control in food animals in the state of Lower Saxony, Germany). For the calculation a yearly turnover-rate of 33% with restocking from within the herd and a possibility of paratuberculosis diagnosis only in animals two years and older were assumed. The development of herd prevalence is exemplarily presented for four herds with different initial prevalences.
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Affiliation(s)
- M Beyerbach
- Institut für Biometrie, Epidemiologie und Informationsverarbeitung, Tierärztlichen Hochschule Hannover
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Stoll R, Renner C, Hansen S, Palme S, Klein C, Belling A, Zeslawski W, Kamionka M, Rehm T, Mühlhahn P, Schumacher R, Hesse F, Kaluza B, Voelter W, Engh RA, Holak TA. Chalcone derivatives antagonize interactions between the human oncoprotein MDM2 and p53. Biochemistry 2001; 40:336-44. [PMID: 11148027 DOI: 10.1021/bi000930v] [Citation(s) in RCA: 218] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The oncoprotein MDM2 inhibits the tumor suppressor protein p53 by binding to the p53 transactivation domain. The p53 gene is inactivated in many human tumors either by mutations or by binding to oncogenic proteins. In some tumors, such as soft tissue sarcomas, overexpression of MDM2 inactivates an otherwise intact p53, disabling the genome integrity checkpoint and allowing cell cycle progression of defective cells. Disruption of the MDM2/p53 interaction leads to increased p53 levels and restored p53 transcriptional activity, indicating restoration of the genome integrity check and therapeutic potential for MDM2/p53 binding antagonists. Here, we show by multidimensional NMR spectroscopy that chalcones (1,3-diphenyl-2-propen-1-ones) are MDM2 inhibitors that bind to a subsite of the p53 binding cleft of human MDM2. Biochemical experiments showed that these compounds can disrupt the MDM2/p53 protein complex, releasing p53 from both the p53/MDM2 and DNA-bound p53/MDM2 complexes. These results thus offer a starting basis for structure-based drug design of cancer therapeutics.
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Affiliation(s)
- R Stoll
- Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany
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Schanbacher BD, Winters SJ, Rehm T, D'Occhio MJ. Pituitary androgen receptors and the resistance of long-term castrated rams to the androgenic control of luteinizing hormone (LH) secretion. J Steroid Biochem 1984; 20:1227-32. [PMID: 6379301 DOI: 10.1016/0022-4731(84)90149-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Luteinizing hormone (LH) responses of short-term (24 h) and long-term (6 mo) castrated rams to testosterone replacement therapy were investigated. Testosterone filled Silastic capsules which maintained physiological concentrations of testosterone in blood (approximately 3.2 ng/ml) prevented the post-castration rise in serum LH of short-term castrated rams but failed to effectively reduce the established elevated serum LH levels in long-term castrated rams. The LH response to exogenous LHRH was also suppressed in the short-term castrated rams, whereas the response was increased in direct proportion to basal LH levels in long-term castrates. The possibility that a change in pituitary androgen receptors may explain the resistance of long-term castrates to testosterone feedback was examined. For this purpose, a cytosolic androgen receptor binding assay was developed using tritiated methyltrienolone (R 1881) as the labeled ligand and dextran-charcoal to separate free and protein-bound steroid. Stable, high affinity (Kd = 0.3-1.5 nM), saturable binding of R 1881 was demonstrated in pituitary cytosol from both intact and castrate rams. Relative binding specificities in intact rams, however, suggested partial binding to a progestin-binding component, whereas receptor binding in long-term castrates was androgen specific. For this reason, androgen receptor binding was studied after addition of triamcinolone acetonide to occupy apparent progestin binding sites. We observed no differences in either androgen receptor concentration (4.10 +/- 0.70 versus 3.23 +/- 0.45 fmol/mg protein; Mean +/- SD) nor ligand affinity at 0 degrees C (Kd = 0.66 +/- 0.34 versus 0.40 +/- 0.08 nM) in 6 mo compared to 24-h castrate rams. These data indicate that the inability of androgens to suppress gonadotropin secretion in long-term castrate rams is unlikely to be related to specific changes in pituitary cytosol androgen receptors.
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