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Arbon D, Mach J, Čadková A, Sipkova A, Stursa J, Klanicová K, Machado M, Ganter M, Levytska V, Sojka D, Truksa J, Werner L, Sutak R. Chelation of Mitochondrial Iron as an Antiparasitic Strategy. ACS Infect Dis 2024; 10:676-687. [PMID: 38287902 PMCID: PMC10862539 DOI: 10.1021/acsinfecdis.3c00529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 01/02/2024] [Accepted: 01/09/2024] [Indexed: 01/31/2024]
Abstract
Iron, as an essential micronutrient, plays a crucial role in host-pathogen interactions. In order to limit the growth of the pathogen, a common strategy of innate immunity includes withdrawing available iron to interfere with the cellular processes of the microorganism. Against that, unicellular parasites have developed powerful strategies to scavenge iron, despite the effort of the host. Iron-sequestering compounds, such as the approved and potent chelator deferoxamine (DFO), are considered a viable option for therapeutic intervention. Since iron is heavily utilized in the mitochondrion, targeting iron chelators in this organelle could constitute an effective therapeutic strategy. This work presents mitochondrially targeted DFO, mitoDFO, as a candidate against a range of unicellular parasites with promising in vitro efficiency. Intracellular Leishmania infection can be cleared by this compound, and experimentation with Trypanosoma brucei 427 elucidates its possible mode of action. The compound not only affects iron homeostasis but also alters the physiochemical properties of the inner mitochondrial membrane, resulting in a loss of function. Furthermore, investigating the virulence factors of pathogenic yeasts confirms that mitoDFO is a viable candidate for therapeutic intervention against a wide spectrum of microbe-associated diseases.
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Affiliation(s)
- Dominik Arbon
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Jan Mach
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Aneta Čadková
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Anna Sipkova
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Jan Stursa
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
- Laboratory
of Clinical Pathophysiology, Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech
Republic
| | - Kristýna Klanicová
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
- Department
of Organic Chemistry, Faculty of Science, Charles University, Prague 128 00, Czech Republic
| | - Marta Machado
- Graduate
Program in Areas of Basic and Applied Biology, Instituto de Ciências
Biomédicas Abel Salazar, Universidade
do Porto, Porto 4050-313, Portugal
- Centre for
Infectious Diseases, Parasitology, Heidelberg
University Hospital, Heidelberg 69120, Germany
| | - Markus Ganter
- Centre for
Infectious Diseases, Parasitology, Heidelberg
University Hospital, Heidelberg 69120, Germany
| | - Viktoriya Levytska
- Institute
of Parasitology, Biology Centre, Academy
of Sciences of the Czech Republic, Branišovská 1160/31, České Budějovice 37005, Czech Republic
| | - Daniel Sojka
- Institute
of Parasitology, Biology Centre, Academy
of Sciences of the Czech Republic, Branišovská 1160/31, České Budějovice 37005, Czech Republic
| | - Jaroslav Truksa
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
| | - Lukáš Werner
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
- Laboratory
of Clinical Pathophysiology, Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech
Republic
| | - Robert Sutak
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
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Bielcikova Z, Werner L, Stursa J, Cerny V, Krizova L, Spacek J, Hlousek S, Vocka M, Bartosova O, Pesta M, Kolostova K, Klezl P, Bobek V, Truksa J, Stemberkova-Hubackova S, Petruzelka L, Michalek P, Neuzil J. Mitochondrially targeted tamoxifen as anticancer therapy: case series of patients with renal cell carcinoma treated in a phase I/Ib clinical trial. Ther Adv Med Oncol 2023; 15:17588359231197957. [PMID: 37786538 PMCID: PMC10541747 DOI: 10.1177/17588359231197957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/03/2023] [Indexed: 10/04/2023] Open
Abstract
Mitochondrially targeted anticancer drugs (mitocans) that disrupt the energy-producing systems of cancer are emerging as new potential therapeutics. Mitochondrially targeted tamoxifen (MitoTam), an inhibitor of mitochondrial respiration respiratory complex I, is a first-in-class mitocan that was tested in the phase I/Ib MitoTam-01 trial of patients with metastatic cancer. MitoTam exhibited a manageable safety profile and efficacy; among 37% (14/38) of responders, the efficacy was greatest in patients with metastatic renal cell carcinoma (RCC) with a clinical benefit rate of 83% (5/6) of patients. This can be explained by the preferential accumulation of MitoTam in the kidney tissue in preclinical studies. Here we report the mechanism of action and safety profile of MitoTam in a case series of RCC patients. All six patients were males with a median age of 69 years, who had previously received at least three lines of palliative systemic therapy and suffered progressive disease before starting MitoTam. We recorded stable disease in four, partial response in one, and progressive disease (PD) in one patient. The histological subtype matched clear cell RCC (ccRCC) in the five responders and claro-cellular carcinoma with sarcomatoid features in the non-responder. The number of circulating tumor cells (CTCs) was evaluated longitudinally to monitor disease dynamics. Beside the decreased number of CTCs after MitoTam administration, we observed a significant decrease of the mitochondrial network mass in enriched CTCs. Two patients had long-term clinical responses to MitoTam, of 50 and 36 weeks. Both patients discontinued treatment due to adverse events, not PD. Two patients who completed the trial in November 2019 and May 2020 are still alive without subsequent anticancer therapy. The toxicity of MitoTam increased with the dosage but was manageable. The efficacy of MitoTam in pretreated ccRCC patients is linked to the novel mechanism of action of this first-in-class mitochondrially targeted drug.
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Affiliation(s)
- Zuzana Bielcikova
- Department of Oncology, General Faculty Hospital, U Nemocnice 499/2, Prague 2, 128 08, Czech Republic
| | - Lukas Werner
- Institute of Biotechnology, Czech Academy of Sciences, Prumyslova 595, Prague-West 252 50, Czech Republic Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| | - Jan Stursa
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech RepublicDiabetes Centre, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| | - Vladimir Cerny
- Department of Radiodiagnostics, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Ludmila Krizova
- Department of Oncology, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Spacek
- Department of Oncology, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Stanislav Hlousek
- Department of Oncology, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Michal Vocka
- Department of Oncology, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Olga Bartosova
- Institute of Pharmacology, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Michal Pesta
- Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Katarina Kolostova
- Laboratory of Personalized Medicine, Oncology Clinic, Faculty Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Petr Klezl
- Laboratory of Personalized Medicine, Oncology Clinic, Faculty Hospital Kralovske Vinohrady, Prague, Czech Republic Urology Clinic, Third Faculty of Medicine, Charles University and Faculty Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Vladimir Bobek
- Laboratory of Personalized Medicine, Oncology Clinic, Faculty Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Jaroslav Truksa
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Sona Stemberkova-Hubackova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech RepublicDiabetes Centre, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| | - Lubos Petruzelka
- Department of Oncology, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Pavel Michalek
- Department of Anesthesiology and Intensive Care, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jiri Neuzil
- School of Pharmacy and Medical Science, Griffith University, Southport, Qld 4222, Australia Department of Pediatrics and Inherited Metabolic Diseases, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic Department of Physiology, Faculty of Science, Charles University, and General University Hospital, Prague, Czech Republic Institute of Biotechnology, Czech Academy of Sciences, Prumyslova 595, Prague-West 252 50, Czech Republic
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3
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Bielcikova Z, Stursa J, Krizova L, Dong L, Spacek J, Hlousek S, Vocka M, Rohlenova K, Bartosova O, Cerny V, Padrta T, Pesta M, Michalek P, Hubackova SS, Kolostova K, Pospisilova E, Bobek V, Klezl P, Zobalova R, Endaya B, Rohlena J, Petruzelka L, Werner L, Neuzil J. Mitochondrially targeted tamoxifen in patients with metastatic solid tumours: an open-label, phase I/Ib single-centre trial. EClinicalMedicine 2023; 57:101873. [PMID: 37064512 PMCID: PMC10102891 DOI: 10.1016/j.eclinm.2023.101873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/10/2023] [Accepted: 01/31/2023] [Indexed: 02/25/2023] Open
Abstract
Background Mitochondria present an emerging target for cancer treatment. We have investigated the effect of mitochondrially targeted tamoxifen (MitoTam), a first-in-class anti-cancer agent, in patients with solid metastatic tumours. Methods MitoTam was tested in an open-label, single-centre (Department of Oncology, General Faculty Hospital, Charles University, Czech Republic), phase I/Ib trial in metastatic patients with various malignancies and terminated oncological therapies. In total, 75 patients were enrolled between May 23, 2018 and July 22, 2020. Phase I evaluated escalating doses of MitoTam in two therapeutic regimens using the 3 + 3 design to establish drug safety and maximum tolerated dose (MTD). In phase Ib, three dosing regimens were applied over 8 and 6 weeks to evaluate long-term toxicity of MitoTam as the primary objective and its anti-cancer effect as a secondary objective. This trial was registered with the European Medicines Agency under EudraCT 2017-004441-25. Findings In total, 37 patients were enrolled into phase I and 38 into phase Ib. In phase I, the initial application of MitoTam via peripheral vein indicated high risk of thrombophlebitis, which was avoided by central vein administration. The highest dose with acceptable side effects was 5.0 mg/kg. The prevailing adverse effects (AEs) in phase I were neutropenia (30%), anaemia (30%) and fever/hyperthermia (30%), and in phase Ib fever/hyperthermia (58%) together with anaemia (26%) and neutropenia (16%). Serious AEs were mostly related to thromboembolic (TE) complications that affected 5% and 13% of patients in phase I and Ib, respectively. The only statistically significant AE related to MitoTam treatment was anaemia in phase Ib (p = 0.004). Of the tested regimens weekly dosing with 3.0 mg/kg for 6 weeks afforded the best safety profile with almost all being grade 1 (G1) AEs. Altogether, five fatalities occurred during the study, two of them meeting criteria for Suspected Unexpected Serious Adverse Events Reporting (SUSAR) (G4 thrombocytopenia and G5 stroke). MitoTam showed benefit evaluated as clinical benefit rate (CBR) in 37% patients with the largest effect in renal cell carcinoma (RCC) where four out of six patients reached disease stabilisation (SD), one reached partial response (PR) so that in total, five out of six (83%) patients showed CBR. Interpretation In this study, the MTD was established as 5.0 mg/kg and the recommended dose of MitoTam as 3.0 mg/kg given once per week via central vein with recommended preventive anti-coagulation therapy. The prevailing toxicity included haematological AEs, hyperthermia/fever and TE complications. One fatal stroke and non-fatal G4 thrombocytopenia were recorded. MitoTam showed high efficacy against RCC. Funding Smart Brain Ltd. Translation For the Czech translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Zuzana Bielcikova
- Department of Oncology, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
- Corresponding author. Department of Oncology, General Faculty Hospital and 1st Faculty of Medicine, Charles University, U Nemocnice 499/2, Prague 2 128 08, Czech Republic.
| | - Jan Stursa
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
| | - Ludmila Krizova
- Department of Oncology, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
| | - Lanfeng Dong
- School of Pharmacy and Medical Science, Griffith University, Southport, Qld 4222, Australia
| | - Jan Spacek
- Department of Oncology, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
| | - Stanislav Hlousek
- Department of Oncology, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
| | - Michal Vocka
- Department of Oncology, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
| | - Katerina Rohlenova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
| | - Olga Bartosova
- Institute of Pharmacology, First Faculty of Medicine, Charles University and General University Hospital, Prague 128 08, Czech Republic
| | - Vladimir Cerny
- Department of Radiodiagnostics, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
| | - Tomas Padrta
- Department of Radiodiagnostics, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
| | - Michal Pesta
- Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University, Prague 121 06, Czech Republic
| | - Pavel Michalek
- Department of Anesthesiology and Intensive Care, First Faculty of Medicine, Charles University and General University Hospital, Prague 128 08, Czech Republic
| | - Sona Stemberkova Hubackova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
- Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague 4 140 21, Czech Republic
| | - Katarina Kolostova
- Laboratory of Personalized Medicine, Oncology Clinic, Faculty Hospital Kralovske Vinohrady, Prague 10 100 34, Czech Republic
| | - Eliska Pospisilova
- Laboratory of Personalized Medicine, Oncology Clinic, Faculty Hospital Kralovske Vinohrady, Prague 10 100 34, Czech Republic
| | - Vladimir Bobek
- Laboratory of Personalized Medicine, Oncology Clinic, Faculty Hospital Kralovske Vinohrady, Prague 10 100 34, Czech Republic
| | - Peter Klezl
- Laboratory of Personalized Medicine, Oncology Clinic, Faculty Hospital Kralovske Vinohrady, Prague 10 100 34, Czech Republic
- Urology Clinic, Third Faculty of Medicine, Charles University and Faculty Hospital Kralovske Vinohrady, Prague 10 100 34, Czech Republic
| | - Renata Zobalova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
| | - Berwini Endaya
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
- Department of Pediatrics and Inherited Metabolic Diseases, First Faculty of Medicine, Charles University, Prague 2 128 08, Czech Republic
| | - Jakub Rohlena
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
| | - Lubos Petruzelka
- Department of Oncology, First Faculty of Medicine, Charles University, and General University Hospital, Prague 128 08, Czech Republic
| | - Lukas Werner
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
- Corresponding author. Institute of Biotechnology, Czech Academy of Sciences, Prumyslova 595, Prague-West 252 50, Czech Republic.
| | - Jiri Neuzil
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West 252 50, Czech Republic
- School of Pharmacy and Medical Science, Griffith University, Southport, Qld 4222, Australia
- Department of Pediatrics and Inherited Metabolic Diseases, First Faculty of Medicine, Charles University, Prague 2 128 08, Czech Republic
- Department of Physiology, Faculty of Science, Charles University, Prague 2 128 00, Czech Republic
- Corresponding author. School of Pharmacy and Medical Science, Griffith University, Parklands Avenue, 4222 Southport, Qld, Australia, or Institute of Biotechnology, Czech Academy of Sciences, Prumyslova 595, Prague-West 252 50, Czech Republic.
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4
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Stemberkova-Hubackova S, Zobalova R, Dubisova M, Smigova J, Dvorakova S, Korinkova K, Ezrova Z, Endaya B, Blazkova K, Vlcak E, Brisudova P, Le DDT, Juhas S, Rosel D, Daniela Kelemen C, Sovilj D, Vacurova E, Cajka T, Filimonenko V, Dong L, Andera L, Hozak P, Brabek J, Bielcikova Z, Stursa J, Werner L, Neuzil J. Simultaneous targeting of mitochondrial metabolism and immune checkpoints as a new strategy for renal cancer therapy. Clin Transl Med 2022; 12:e645. [PMID: 35352502 PMCID: PMC8964933 DOI: 10.1002/ctm2.645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/23/2021] [Accepted: 10/30/2021] [Indexed: 11/29/2022] Open
Affiliation(s)
| | - Renata Zobalova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Maria Dubisova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,Faculty of Science, Charles University, Prague 1, Czech Republic
| | - Jana Smigova
- Faculty of Science, Charles University, Prague 1, Czech Republic
| | - Sarka Dvorakova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Klara Korinkova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,Faculty of Science, Charles University, Prague 1, Czech Republic
| | - Zuzana Ezrova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Berwini Endaya
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,School of Pharmacy and Medical Science, Griffith University, Southport, Qld, Australia
| | - Kristyna Blazkova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Erik Vlcak
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague 4, Czech Republic
| | - Petra Brisudova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Dan-Diem Thi Le
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Stefan Juhas
- Institute of Animal Physiology and Genetics, Czech Academy of Science, PIGMOD Centre, Libechov, Czech Republic
| | - Daniel Rosel
- Faculty of Science, Charles University, Prague 1, Czech Republic
| | - Cristina Daniela Kelemen
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,Faculty of Science, Charles University, Prague 1, Czech Republic
| | - Dana Sovilj
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Eliska Vacurova
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,Faculty of Science, Charles University, Prague 1, Czech Republic
| | - Tomas Cajka
- Institute of Physiology, Czech Academy of Sciences, Prague 4, Czech Republic
| | - Vlada Filimonenko
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague 4, Czech Republic
| | - Lanfeng Dong
- School of Pharmacy and Medical Science, Griffith University, Southport, Qld, Australia
| | - Ladislav Andera
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Pavel Hozak
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague 4, Czech Republic
| | - Jan Brabek
- Faculty of Science, Charles University, Prague 1, Czech Republic
| | | | - Jan Stursa
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Lukas Werner
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic
| | - Jiri Neuzil
- Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,School of Pharmacy and Medical Science, Griffith University, Southport, Qld, Australia
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Stefanik M, Simeckova E, Bem P, Stursa J, Zach V, Mrazek J. Neutron spectrum determination of accelerator-driven d(10)+Be neutron source using the multi-foil activation technique. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109767] [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: 11/25/2022]
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Sandoval-Acuña C, Torrealba N, Tomkova V, Jadhav SB, Blazkova K, Merta L, Lettlova S, Adamcová MK, Rosel D, Brábek J, Neuzil J, Stursa J, Werner L, Truksa J. Targeting Mitochondrial Iron Metabolism Suppresses Tumor Growth and Metastasis by Inducing Mitochondrial Dysfunction and Mitophagy. Cancer Res 2021; 81:2289-2303. [PMID: 33685989 DOI: 10.1158/0008-5472.can-20-1628] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/20/2020] [Accepted: 03/01/2021] [Indexed: 11/16/2022]
Abstract
Deferoxamine (DFO) represents a widely used iron chelator for the treatment of iron overload. Here we describe the use of mitochondrially targeted deferoxamine (mitoDFO) as a novel approach to preferentially target cancer cells. The agent showed marked cytostatic, cytotoxic, and migrastatic properties in vitro, and it significantly suppressed tumor growth and metastasis in vivo. The underlying molecular mechanisms included (i) impairment of iron-sulfur [Fe-S] cluster/heme biogenesis, leading to destabilization and loss of activity of [Fe-S] cluster/heme containing enzymes, (ii) inhibition of mitochondrial respiration leading to mitochondrial reactive oxygen species production, resulting in dysfunctional mitochondria with markedly reduced supercomplexes, and (iii) fragmentation of the mitochondrial network and induction of mitophagy. Mitochondrial targeting of deferoxamine represents a way to deprive cancer cells of biologically active iron, which is incompatible with their proliferation and invasion, without disrupting systemic iron metabolism. Our findings highlight the importance of mitochondrial iron metabolism for cancer cells and demonstrate repurposing deferoxamine into an effective anticancer drug via mitochondrial targeting. SIGNIFICANCE: These findings show that targeting the iron chelator deferoxamine to mitochondria impairs mitochondrial respiration and biogenesis of [Fe-S] clusters/heme in cancer cells, which suppresses proliferation and migration and induces cell death. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/9/2289/F1.large.jpg.
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Affiliation(s)
- Cristian Sandoval-Acuña
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Natalia Torrealba
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Veronika Tomkova
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Sukanya B Jadhav
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Kristyna Blazkova
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Ladislav Merta
- Faculty of Sciences, BIOCEV Research Center, Charles University, Vestec, Czech Republic
| | - Sandra Lettlova
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Miroslava K Adamcová
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Daniel Rosel
- Faculty of Sciences, BIOCEV Research Center, Charles University, Vestec, Czech Republic
| | - Jan Brábek
- Faculty of Sciences, BIOCEV Research Center, Charles University, Vestec, Czech Republic
| | - Jiri Neuzil
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic.,School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Jan Stursa
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Lukas Werner
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic
| | - Jaroslav Truksa
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Vestec, Czech Republic.
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Stefanik M, Bem P, Simeckova E, Stursa J, Majerle M, Mrazek J. The p(20)+Be reaction as a source of fusion relevant neutrons. Fusion Engineering and Design 2020. [DOI: 10.1016/j.fusengdes.2020.112053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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8
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Stefanik M, Simeckova E, Bem P, Majerle M, Novak J, Ansorge M, Mrazek J, Stursa J. Neutron spectrum determination of p+Be reaction for 30 MeV protons using the multi-foil activation technique. EPJ Web Conf 2020. [DOI: 10.1051/epjconf/202023917015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
At the NPI in Rez, the p + Be source reaction was investigated for 30 MeV proton beam and thick beryllium target. For neutron field determination of the p(30)+Be source reaction in close source-to-sample distance, the multi-foil activation technique with a set of 10 activation materials (Au, Co, Lu, Ti, In, Al, Y, Fe, Ni, Nb) was utilized. From resulting reaction rates, the neutron spectrum was reconstructed using the SAND-II unfolding code. New neutron field of white spectrum up to 28 MeV has an intensity of 8.6 × 1010 cm−2s−1 close to target. The obtained neutron field extends the utilization of cyclotron-based fast neutron sources at the NPI and provides new experimental opportunities for future irradiation experiments such as fast neutron activation analysis, nuclear data validation, and radiation damage study of electronics and materials for nuclear energetics.
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Stefanik M, Bem P, Simeckova E, Stursa J, Zach V, Majerle M. Neutron field study of p(24) + Be source reaction using the multi-foil activation technique. Fusion Engineering and Design 2019. [DOI: 10.1016/j.fusengdes.2019.03.100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Stefanik M, Bem P, Majerle M, Novak J, Simeckova E, Stursa J. Neutron field study of p(35) + Be source reaction at the NPI Rez. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2018.06.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Havlik J, Petrakova V, Kucka J, Raabova H, Panek D, Stepan V, Zlamalova Cilova Z, Reineck P, Stursa J, Kucera J, Hruby M, Cigler P. Extremely rapid isotropic irradiation of nanoparticles with ions generated in situ by a nuclear reaction. Nat Commun 2018; 9:4467. [PMID: 30367036 PMCID: PMC6203839 DOI: 10.1038/s41467-018-06789-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 09/24/2018] [Indexed: 12/28/2022] Open
Abstract
Energetic ions represent an important tool for the creation of controlled structural defects in solid nanomaterials. However, the current preparative irradiation techniques in accelerators show significant limitations in scaling-up, because only very thin layers of nanoparticles can be efficiently and homogeneously irradiated. Here, we show an easily scalable method for rapid irradiation of nanomaterials by light ions formed homogeneously in situ by a nuclear reaction. The target nanoparticles are embedded in B2O3 and placed in a neutron flux. Neutrons captured by 10B generate an isotropic flux of energetic α particles and 7Li+ ions that uniformly irradiates the surrounding nanoparticles. We produced 70 g of fluorescent nanodiamonds in an approximately 30-minute irradiation session, as well as fluorescent silicon carbide nanoparticles. Our method thus increased current preparative yields by a factor of 102-103. We envision that our technique will increase the production of ion-irradiated nanoparticles, facilitating their use in various applications.
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Affiliation(s)
- Jan Havlik
- Institute of Organic Chemistry and Biochemistry of the CAS, Flemingovo nam. 2, 166 10 Prague 6, Prague, Czech Republic
- Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague 2, Prague, Czech Republic
| | - Vladimira Petrakova
- Faculty of Biomedical Engineering, Czech Technical University in Prague, nam. Sitna 3105, 272 01, Kladno, Czech Republic
| | - Jan Kucka
- Institute of Macromolecular Chemistry of the CAS, Heyrovskeho nam. 2, 162 06 Prague 6, Prague, Czech Republic
| | - Helena Raabova
- Institute of Organic Chemistry and Biochemistry of the CAS, Flemingovo nam. 2, 166 10 Prague 6, Prague, Czech Republic
- University of Chemistry and Technology, Prague, Technicka 5, 166 28 Prague 6, Prague, Czech Republic
| | - Dalibor Panek
- Faculty of Biomedical Engineering, Czech Technical University in Prague, nam. Sitna 3105, 272 01, Kladno, Czech Republic
| | - Vaclav Stepan
- Nuclear Physics Institute of the CAS, 250 68 Husinec-Rez 130, Prague, Czech Republic
| | - Zuzana Zlamalova Cilova
- University of Chemistry and Technology, Prague, Technicka 5, 166 28 Prague 6, Prague, Czech Republic
| | - Philipp Reineck
- ARC Centre of Excellence for Nanoscale BioPhotonics, School of Science, RMIT University, Melbourne, VIC, 3001, Australia
| | - Jan Stursa
- Nuclear Physics Institute of the CAS, 250 68 Husinec-Rez 130, Prague, Czech Republic
| | - Jan Kucera
- Nuclear Physics Institute of the CAS, 250 68 Husinec-Rez 130, Prague, Czech Republic
| | - Martin Hruby
- Institute of Macromolecular Chemistry of the CAS, Heyrovskeho nam. 2, 162 06 Prague 6, Prague, Czech Republic.
| | - Petr Cigler
- Institute of Organic Chemistry and Biochemistry of the CAS, Flemingovo nam. 2, 166 10 Prague 6, Prague, Czech Republic.
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12
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Cuyàs E, Verdura S, Llorach-Pares L, Fernández-Arroyo S, Luciano-Mateo F, Cabré N, Stursa J, Werner L, Martin-Castillo B, Viollet B, Neuzil J, Joven J, Nonell-Canals A, Sanchez-Martinez M, Menendez JA. Metformin directly targets the H3K27me3 demethylase KDM6A/UTX. Aging Cell 2018; 17:e12772. [PMID: 29740925 PMCID: PMC6052472 DOI: 10.1111/acel.12772] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [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] [Accepted: 03/28/2018] [Indexed: 12/22/2022] Open
Abstract
Metformin, the first drug chosen to be tested in a clinical trial aimed to target the biology of aging per se, has been clinically exploited for decades in the absence of a complete understanding of its therapeutic targets or chemical determinants. We here outline a systematic chemoinformatics approach to computationally predict biomolecular targets of metformin. Using several structure‐ and ligand‐based software tools and reference databases containing 1,300,000 chemical compounds and more than 9,000 binding sites protein cavities, we identified 41 putative metformin targets including several epigenetic modifiers such as the member of the H3K27me3‐specific demethylase subfamily, KDM6A/UTX. AlphaScreen and AlphaLISA assays confirmed the ability of metformin to inhibit the demethylation activity of purified KDM6A/UTX enzyme. Structural studies revealed that metformin might occupy the same set of residues involved in H3K27me3 binding and demethylation within the catalytic pocket of KDM6A/UTX. Millimolar metformin augmented global levels of H3K27me3 in cultured cells, including reversion of global loss of H3K27me3 occurring in premature aging syndromes, irrespective of mitochondrial complex I or AMPK. Pharmacological doses of metformin in drinking water or intraperitoneal injection significantly elevated the global levels of H3K27me3 in the hepatic tissue of low‐density lipoprotein receptor‐deficient mice and in the tumor tissues of highly aggressive breast cancer xenograft‐bearing mice. Moreover, nondiabetic breast cancer patients receiving oral metformin in addition to standard therapy presented an elevated level of circulating H3K27me3. Our biocomputational approach coupled to experimental validation reveals that metformin might directly regulate the biological machinery of aging by targeting core chromatin modifiers of the epigenome.
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Affiliation(s)
- Elisabet Cuyàs
- ProCURE (Program Against Cancer Therapeutic Resistance); Metabolism & Cancer Group; Catalan Institute of Oncology; Girona Catalonia Spain
- Girona Biomedical Research Institute (IDIBGI); Girona Spain
| | - Sara Verdura
- ProCURE (Program Against Cancer Therapeutic Resistance); Metabolism & Cancer Group; Catalan Institute of Oncology; Girona Catalonia Spain
- Girona Biomedical Research Institute (IDIBGI); Girona Spain
| | | | - Salvador Fernández-Arroyo
- Unitat de Recerca Biomèdica; Hospital Universitari de Sant Joan; IISPV; Rovira i Virgili University; Reus Spain
| | - Fedra Luciano-Mateo
- Unitat de Recerca Biomèdica; Hospital Universitari de Sant Joan; IISPV; Rovira i Virgili University; Reus Spain
| | - Noemí Cabré
- Unitat de Recerca Biomèdica; Hospital Universitari de Sant Joan; IISPV; Rovira i Virgili University; Reus Spain
| | - Jan Stursa
- Institute of Chemical Technology; Prague Czech Republic
- Institute of Biotechnology; Czech Academy of Sciences; Prague-West Czech Republic
| | - Lukas Werner
- Institute of Chemical Technology; Prague Czech Republic
- Institute of Biotechnology; Czech Academy of Sciences; Prague-West Czech Republic
| | | | - Benoit Viollet
- INSERM U1016; Institut Cochin; Paris France
- CNRS UMR 8104; Paris France
- Université Paris Descartes; Sorbonne Paris Cité; Paris France
| | - Jiri Neuzil
- Institute of Biotechnology; Czech Academy of Sciences; Prague-West Czech Republic
- School of Medical Science; Menzies Health Institute Queensland; Griffith University; Southport Queensland Australia
| | - Jorge Joven
- Unitat de Recerca Biomèdica; Hospital Universitari de Sant Joan; IISPV; Rovira i Virgili University; Reus Spain
| | | | | | - Javier A. Menendez
- ProCURE (Program Against Cancer Therapeutic Resistance); Metabolism & Cancer Group; Catalan Institute of Oncology; Girona Catalonia Spain
- Girona Biomedical Research Institute (IDIBGI); Girona Spain
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13
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Stefanik M, Bem P, Majerle M, Novak J, Simeckova E, Stursa J. NEUTRON FIELD MEASUREMENT OF P(35)+Be SOURCE USING THE MULTI-FOIL ACTIVATION METHOD. Radiat Prot Dosimetry 2018; 180:377-381. [PMID: 29216389 DOI: 10.1093/rpd/ncx249] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 11/02/2017] [Indexed: 06/07/2023]
Abstract
Neutron field from the p+Be interaction was investigated at the NPI CAS for a proton beam energy of 35 MeV and thick beryllium target. Broad neutron spectra at close source-to-sample distances were determined using the multi-foil activation technique. Two large sets of dosimetry foils containing the Ni, Co, Au, In, Ti, Al, Y, Lu, Nb and Fe were irradiated at a distance of 74 mm at direct neutron beam axis and at a distance of 34 mm from beam axis. Supporting Monte-Carlo MCNPX calculations of the irradiation system were performed as well. From measured reaction rates, the neutron energy spectra at both positions were reconstructed employing the modified version of the SAND-II unfolding code and activation cross-section data from the EAF-2010 library. At the position of irradiated samples, the total fast neutron flux reaches the value up to 1010 cm-2 s-1, and the neutron field is utilizable for radiation hardness study and integral benchmark experiments within the International Fusion Material Irradiation Facility (IFMIF) program.
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Affiliation(s)
- Milan Stefanik
- Nuclear Physics Institute of The Czech Academy of Sciences p.r.i., 25068 Rez 130, Czech Republic
- Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 7, Prague, Czech Republic
| | - Pavel Bem
- Nuclear Physics Institute of The Czech Academy of Sciences p.r.i., 25068 Rez 130, Czech Republic
| | - Mitja Majerle
- Nuclear Physics Institute of The Czech Academy of Sciences p.r.i., 25068 Rez 130, Czech Republic
| | - Jan Novak
- Nuclear Physics Institute of The Czech Academy of Sciences p.r.i., 25068 Rez 130, Czech Republic
| | - Eva Simeckova
- Nuclear Physics Institute of The Czech Academy of Sciences p.r.i., 25068 Rez 130, Czech Republic
| | - Jan Stursa
- Nuclear Physics Institute of The Czech Academy of Sciences p.r.i., 25068 Rez 130, Czech Republic
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14
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Rohlenova K, Sachaphibulkij K, Stursa J, Bezawork-Geleta A, Blecha J, Endaya B, Werner L, Cerny J, Zobalova R, Goodwin J, Spacek T, Alizadeh Pesdar E, Yan B, Nguyen MN, Vondrusova M, Sobol M, Jezek P, Hozak P, Truksa J, Rohlena J, Dong LF, Neuzil J. Selective Disruption of Respiratory Supercomplexes as a New Strategy to Suppress Her2 high Breast Cancer. Antioxid Redox Signal 2017; 26:84-103. [PMID: 27392540 PMCID: PMC5206771 DOI: 10.1089/ars.2016.6677] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AIMS Expression of the HER2 oncogene in breast cancer is associated with resistance to treatment, and Her2 may regulate bioenergetics. Therefore, we investigated whether disruption of the electron transport chain (ETC) is a viable strategy to eliminate Her2high disease. RESULTS We demonstrate that Her2high cells and tumors have increased assembly of respiratory supercomplexes (SCs) and increased complex I-driven respiration in vitro and in vivo. They are also highly sensitive to MitoTam, a novel mitochondrial-targeted derivative of tamoxifen. Unlike tamoxifen, MitoTam efficiently suppresses experimental Her2high tumors without systemic toxicity. Mechanistically, MitoTam inhibits complex I-driven respiration and disrupts respiratory SCs in Her2high background in vitro and in vivo, leading to elevated reactive oxygen species production and cell death. Intriguingly, higher sensitivity of Her2high cells to MitoTam is dependent on the mitochondrial fraction of Her2. INNOVATION Oncogenes such as HER2 can restructure ETC, creating a previously unrecognized therapeutic vulnerability exploitable by SC-disrupting agents such as MitoTam. CONCLUSION We propose that the ETC is a suitable therapeutic target in Her2high disease. Antioxid. Redox Signal. 26, 84-103.
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Affiliation(s)
- Katerina Rohlenova
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic
| | | | - Jan Stursa
- 2 School of Medical Science, Griffith University , Southport, Australia .,3 Prague Institute of Chemical Technology , Prague, Czech Republic .,4 Biomedical Research Center, University Hospital , Hradec Kralove, Czech Republic
| | | | - Jan Blecha
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic
| | - Berwini Endaya
- 2 School of Medical Science, Griffith University , Southport, Australia
| | - Lukas Werner
- 4 Biomedical Research Center, University Hospital , Hradec Kralove, Czech Republic
| | - Jiri Cerny
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic
| | - Renata Zobalova
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic .,2 School of Medical Science, Griffith University , Southport, Australia
| | - Jacob Goodwin
- 2 School of Medical Science, Griffith University , Southport, Australia
| | - Tomas Spacek
- 5 Institute of Physiology , Prague, Czech Republic
| | | | - Bing Yan
- 2 School of Medical Science, Griffith University , Southport, Australia
| | - Maria Nga Nguyen
- 2 School of Medical Science, Griffith University , Southport, Australia
| | - Magdalena Vondrusova
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic
| | - Margaryta Sobol
- 6 Institute of Molecular Genetics , Czech Academy of Sciences, Prague, Czech Republic
| | - Petr Jezek
- 5 Institute of Physiology , Prague, Czech Republic
| | - Pavel Hozak
- 6 Institute of Molecular Genetics , Czech Academy of Sciences, Prague, Czech Republic
| | - Jaroslav Truksa
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic
| | - Jakub Rohlena
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic
| | - Lan-Feng Dong
- 2 School of Medical Science, Griffith University , Southport, Australia
| | - Jiri Neuzil
- 1 Institute of Biotechnology , Czech Academy of Sciences, BIOCEV, Vestec, Prague-West, Czech Republic .,2 School of Medical Science, Griffith University , Southport, Australia
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15
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Boukalova S, Stursa J, Werner L, Ezrova Z, Cerny J, Bezawork-Geleta A, Pecinova A, Dong L, Drahota Z, Neuzil J. Mitochondrial Targeting of Metformin Enhances Its Activity against Pancreatic Cancer. Mol Cancer Ther 2016; 15:2875-2886. [PMID: 27765848 DOI: 10.1158/1535-7163.mct-15-1021] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 08/30/2016] [Accepted: 09/20/2016] [Indexed: 11/16/2022]
Abstract
Pancreatic cancer is one of the hardest-to-treat types of neoplastic diseases. Metformin, a widely prescribed drug against type 2 diabetes mellitus, is being trialed as an agent against pancreatic cancer, although its efficacy is low. With the idea of delivering metformin to its molecular target, the mitochondrial complex I (CI), we tagged the agent with the mitochondrial vector, triphenylphosphonium group. Mitochondrially targeted metformin (MitoMet) was found to kill a panel of pancreatic cancer cells three to four orders of magnitude more efficiently than found for the parental compound. Respiration assessment documented CI as the molecular target for MitoMet, which was corroborated by molecular modeling. MitoMet also efficiently suppressed pancreatic tumors in three mouse models. We propose that the novel mitochondrially targeted agent is clinically highly intriguing, and it has a potential to greatly improve the bleak prospects of patients with pancreatic cancer. Mol Cancer Ther; 15(12); 2875-86. ©2016 AACR.
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Affiliation(s)
- Stepana Boukalova
- Institute of Biotechnology, Czech Academy of Sciences, Vestec, Czech Republic.
| | - Jan Stursa
- Institute of Chemical Technology in Prague, Czech Republic
| | - Lukas Werner
- Institute of Chemical Technology in Prague, Czech Republic
- Biomedical Research Centre, University Hospital Hradec Kralove, Czech Republic
| | - Zuzana Ezrova
- Institute of Biotechnology, Czech Academy of Sciences, Vestec, Czech Republic
| | - Jiri Cerny
- Institute of Biotechnology, Czech Academy of Sciences, Vestec, Czech Republic
| | | | - Alena Pecinova
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Lanfeng Dong
- School of Medical Science, Griffith University, Southport, Qld, Australia
| | - Zdenek Drahota
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Jiri Neuzil
- Institute of Biotechnology, Czech Academy of Sciences, Vestec, Czech Republic.
- School of Medical Science, Griffith University, Southport, Qld, Australia
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16
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Petrakova V, Benson V, Buncek M, Fiserova A, Ledvina M, Stursa J, Cigler P, Nesladek M. Imaging of transfection and intracellular release of intact, non-labeled DNA using fluorescent nanodiamonds. Nanoscale 2016; 8:12002-12. [PMID: 27240633 DOI: 10.1039/c6nr00610h] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Efficient delivery of stabilized nucleic acids (NAs) into cells and release of the NA payload are crucial points in the transfection process. Here we report on the fabrication of a nanoscopic cellular delivery carrier that is additionally combined with a label-free intracellular sensor device, based on biocompatible fluorescent nanodiamond particles. The sensing function is engineered into nanodiamonds by using nitrogen-vacancy color centers, providing stable non-blinking luminescence. The device is used for monitoring NA transfection and the payload release in cells. The unpacking of NAs from a poly(ethyleneimine)-terminated nanodiamond surface is monitored using the color shift of nitrogen-vacancy centers in the diamond, which serve as a nanoscopic electric charge sensor. The proposed device innovates the strategies for NA imaging and delivery, by providing detection of the intracellular release of non-labeled NAs without affecting cellular processing of the NAs. Our system highlights the potential of nanodiamonds to act not merely as labels but also as non-toxic and non-photobleachable fluorescent biosensors reporting complex molecular events.
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Affiliation(s)
- V Petrakova
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna sq. 3105, 272 01 Kladno, Czech Republic and Institute of Physics AS CR, v.v.i, Na Slovance 1999/2, 182 21 Prague 8, Czech Republic
| | - V Benson
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna sq. 3105, 272 01 Kladno, Czech Republic and Institute of Microbiology AS CR, v.v.i, Videnska 1083, 142 20 Prague 4, Czech Republic
| | - M Buncek
- Generi Biotech Ltd., Machkova 587, 500 11 Hradec Kralove, Czech Republic
| | - A Fiserova
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna sq. 3105, 272 01 Kladno, Czech Republic and Institute of Microbiology AS CR, v.v.i, Videnska 1083, 142 20 Prague 4, Czech Republic
| | - M Ledvina
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna sq. 3105, 272 01 Kladno, Czech Republic and Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2, 166 10 Prague 6, Czech Republic.
| | - J Stursa
- Nuclear Physics Institute AS CR, v.v.i., 250 68, Rez near Prague, Czech Republic
| | - P Cigler
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2, 166 10 Prague 6, Czech Republic.
| | - M Nesladek
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna sq. 3105, 272 01 Kladno, Czech Republic and IMEC Division IMOMEC, Hasselt University, Wetenschapspark 1, B-3590, Diepenbeek, Belgium and Institute for Materials Research, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium.
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17
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Pasdar EA, Smits M, Stapelberg M, Bajzikova M, Stantic M, Goodwin J, Yan B, Stursa J, Kovarova J, Sachaphibulkij K, Bezawork-Geleta A, Sobol M, Filimonenko A, Tomasetti M, Zobalova R, Hozak P, Dong LF, Neuzil J. Correction: Characterisation of Mesothelioma-Initiating Cells and Their Susceptibility to Anti-Cancer Agents. PLoS One 2016; 11:e0156012. [PMID: 27186640 PMCID: PMC4871491 DOI: 10.1371/journal.pone.0156012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0119549.].
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18
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Petrakova V, Rehor I, Stursa J, Ledvina M, Nesladek M, Cigler P. Charge-sensitive fluorescent nanosensors created from nanodiamonds. Nanoscale 2015; 7:12307-11. [PMID: 26138745 DOI: 10.1039/c5nr00712g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We show that fluorescent nanodiamonds (FNDs) are among the few types of nanosensors that enable direct optical reading of noncovalent molecular events. The unique sensing mechanism is based on switching between the negatively charged and neutral states of NV centers which is induced by the interaction of the FND surface with charged molecules.
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Affiliation(s)
- V Petrakova
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna sq. 3105, 272 01 Kladno, Czech Republic.
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19
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Yan B, Stantic M, Zobalova R, Bezawork-Geleta A, Stapelberg M, Stursa J, Prokopova K, Dong L, Neuzil J. Mitochondrially targeted vitamin E succinate efficiently kills breast tumour-initiating cells in a complex II-dependent manner. BMC Cancer 2015; 15:401. [PMID: 25967547 PMCID: PMC4494715 DOI: 10.1186/s12885-015-1394-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/29/2015] [Indexed: 12/31/2022] Open
Abstract
Background Accumulating evidence suggests that breast cancer involves tumour-initiating cells (TICs), which play a role in initiation, metastasis, therapeutic resistance and relapse of the disease. Emerging drugs that target TICs are becoming a focus of contemporary research. Mitocans, a group of compounds that induce apoptosis of cancer cells by destabilising their mitochondria, are showing their potential in killing TICs. In this project, we investigated mitochondrially targeted vitamin E succinate (MitoVES), a recently developed mitocan, for its in vitro and in vivo efficacy against TICs. Methods The mammosphere model of breast TICs was established by culturing murine NeuTL and human MCF7 cells as spheres. This model was verified by stem cell marker expression, tumour initiation capacity and chemotherapeutic resistance. Cell susceptibility to MitoVES was assessed and the cell death pathway investigated. In vivo efficacy was studied by grafting NeuTL TICs to form syngeneic tumours. Results Mammospheres derived from NeuTL and MCF7 breast cancer cells were enriched in the level of stemness, and the sphere cells featured altered mitochondrial function. Sphere cultures were resistant to several established anti-cancer agents while they were susceptible to MitoVES. Killing of mammospheres was suppressed when the mitochondrial complex II, the molecular target of MitoVES, was knocked down. Importantly, MitoVES inhibited progression of syngeneic HER2high tumours derived from breast TICs by inducing apoptosis in tumour cells. Conclusions These results demonstrate that using mammospheres, a plausible model for studying TICs, drugs that target mitochondria efficiently kill breast tumour-initiating cells. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1394-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bing Yan
- School of Medical Science, Griffith University, Southport, Qld, 4222, Australia.
| | - Marina Stantic
- School of Medical Science, Griffith University, Southport, Qld, 4222, Australia.
| | - Renata Zobalova
- School of Medical Science, Griffith University, Southport, Qld, 4222, Australia. .,Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, 142 20, Czech Republic.
| | | | - Michael Stapelberg
- School of Medical Science, Griffith University, Southport, Qld, 4222, Australia.
| | - Jan Stursa
- The Department of Chemistry of Natural Compounds, University of Chemistry and Technology, Prague, Czech Republic.
| | - Katerina Prokopova
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, 142 20, Czech Republic.
| | - Lanfeng Dong
- School of Medical Science, Griffith University, Southport, Qld, 4222, Australia.
| | - Jiri Neuzil
- School of Medical Science, Griffith University, Southport, Qld, 4222, Australia. .,Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, 142 20, Czech Republic.
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20
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Pasdar EA, Smits M, Stapelberg M, Bajzikova M, Stantic M, Goodwin J, Yan B, Stursa J, Kovarova J, Sachaphibulkij K, Bezawork-Geleta A, Sobol M, Filimonenko A, Tomasetti M, Zobalova R, Hozak P, Dong LF, Neuzil J. Characterisation of mesothelioma-initiating cells and their susceptibility to anti-cancer agents. PLoS One 2015; 10:e0119549. [PMID: 25932953 PMCID: PMC4416766 DOI: 10.1371/journal.pone.0119549] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/14/2015] [Indexed: 01/06/2023] Open
Abstract
Malignant mesothelioma (MM) is an aggressive type of tumour causing high mortality. One reason for this paradigm may be the existence of a subpopulation of tumour-initiating cells (TICs) that endow MM with drug resistance and recurrence. The objective of this study was to identify and characterise a TIC subpopulation in MM cells, using spheroid cultures, mesospheres, as a model of MM TICs. Mesospheres, typified by the stemness markers CD24, ABCG2 and OCT4, initiated tumours in immunodeficient mice more efficiently than adherent cells. CD24 knock-down cells lost the sphere-forming capacity and featured lower tumorigenicity. Upon serial transplantation, mesospheres were gradually more efficiently tumrigenic with increased level of stem cell markers. We also show that mesospheres feature mitochondrial and metabolic properties similar to those of normal and cancer stem cells. Finally, we show that mesothelioma-initiating cells are highly susceptible to mitochondrially targeted vitamin E succinate. This study documents that mesospheres can be used as a plausible model of mesothelioma-initiating cells and that they can be utilised in the search for efficient agents against MM.
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Affiliation(s)
| | - Michael Smits
- School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Michael Stapelberg
- School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Martina Bajzikova
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Marina Stantic
- School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Jacob Goodwin
- School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Bing Yan
- School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Jan Stursa
- Biomedical Research Center, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jaromira Kovarova
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | | | - Margaryta Sobol
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Anatoly Filimonenko
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Marco Tomasetti
- Department of Molecular and Clinical Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Renata Zobalova
- School of Medical Science, Griffith University, Southport, Queensland, Australia
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Pavel Hozak
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Lan-Feng Dong
- School of Medical Science, Griffith University, Southport, Queensland, Australia
| | - Jiri Neuzil
- School of Medical Science, Griffith University, Southport, Queensland, Australia
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- * E-mail:
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Truksa J, Dong LF, Rohlena J, Stursa J, Vondrusova M, Goodwin J, Nguyen M, Kluckova K, Rychtarcikova Z, Lettlova S, Spacilova J, Stapelberg M, Zoratti M, Neuzil J. Mitochondrially targeted vitamin E succinate modulates expression of mitochondrial DNA transcripts and mitochondrial biogenesis. Antioxid Redox Signal 2015; 22:883-900. [PMID: 25578105 DOI: 10.1089/ars.2013.5594] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
AIMS To assess the effect of mitochondrially targeted vitamin E (VE) analogs on mitochondrial function and biogenesis. RESULTS Mitochondrially targeted vitamin E succinate (MitoVES) is an efficient inducer of apoptosis in cancer cells. Here, we show that unlike its untargeted counterpart α-tocopheryl succinate, MitoVES suppresses proliferation of cancer cells at sub-apoptotic doses by way of affecting the mitochondrial DNA (mtDNA) transcripts. We found that MitoVES strongly suppresses the level of the displacement loop transcript followed by those of mtDNA genes coding for subunits of mitochondrial complexes. This process is coupled to the inhibition of mitochondrial respiration, dissipation of the mitochondrial membrane potential, and generation of reactive oxygen species. In addition, exposure of cancer cells to MitoVES led to decreased expression of TFAM and diminished mitochondrial biogenesis. The inhibition of mitochondrial transcription was replicated in vivo in a mouse model of HER2(high) breast cancer, where MitoVES lowered the level of mtDNA transcripts in cancer cells but not in normal tissue. INNOVATION Our data show that mitochondrially targeted VE analogs represent a novel class of mitocans that not only induce apoptosis at higher concentrations but also block proliferation and suppress normal mitochondrial function and transcription at low, non-apoptogenic doses. CONCLUSIONS Our data indicate a novel, selective anti-cancer activity of compounds that act by targeting mitochondria of cancer cells, inducing significant alterations in mitochondrial function associated with transcription of mtDNA-coded genes. These changes subsequently result in the arrest of cell proliferation.
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Affiliation(s)
- Jaroslav Truksa
- 1 Molecular Therapy Group, Institute of Biotechnology , Academy of Sciences of the Czech Republic, Prague, Czech Republic
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22
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Slegerova J, Hajek M, Rehor I, Sedlak F, Stursa J, Hruby M, Cigler P. Designing the nanobiointerface of fluorescent nanodiamonds: highly selective targeting of glioma cancer cells. Nanoscale 2015; 7:415-20. [PMID: 25132312 DOI: 10.1039/c4nr02776k] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Core-shell nanoparticles based on fluorescent nanodiamonds coated with a biocompatible N-(2-hydroxypropyl)methacrylamide copolymer shell were developed for background-free near-infrared imaging of cancer cells. The particles showed excellent colloidal stability in buffers and culture media. After conjugation with a cyclic RGD peptide they selectively targeted integrin αvβ3 receptors on glioblastoma cells with high internalization efficacy.
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Affiliation(s)
- Jitka Slegerova
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2, 166 10, Prague 6, Czech Republic.
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Yanamala N, Kapralov AA, Djukic M, Peterson J, Mao G, Klein-Seetharaman J, Stoyanovsky DA, Stursa J, Neuzil J, Kagan VE. Structural re-arrangement and peroxidase activation of cytochrome c by anionic analogues of vitamin E, tocopherol succinate and tocopherol phosphate. J Biol Chem 2014; 289:32488-98. [PMID: 25278024 DOI: 10.1074/jbc.m114.601377] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cytochrome c is a multifunctional hemoprotein in the mitochondrial intermembrane space whereby its participation in electron shuttling between respiratory complexes III and IV is alternative to its role in apoptosis as a peroxidase activated by interaction with cardiolipin (CL), and resulting in selective CL peroxidation. The switch from electron transfer to peroxidase function requires partial unfolding of the protein upon binding of CL, whose specific features combine negative charges of the two phosphate groups with four hydrophobic fatty acid residues. Assuming that other endogenous small molecule ligands with a hydrophobic chain and a negatively charged functionality may activate cytochrome c into a peroxidase, we investigated two hydrophobic anionic analogues of vitamin E, α-tocopherol succinate (α-TOS) and α-tocopherol phosphate (α-TOP), as potential inducers of peroxidase activity of cytochrome c. NMR studies and computational modeling indicate that they interact with cytochrome c at similar sites previously proposed for CL. Absorption spectroscopy showed that both analogues effectively disrupt the Fe-S(Met(80)) bond associated with unfolding of cytochrome c. We found that α-TOS and α-TOP stimulate peroxidase activity of cytochrome c. Enhanced peroxidase activity was also observed in isolated rat liver mitochondria incubated with α-TOS and tBOOH. A mitochondria-targeted derivative of TOS, triphenylphosphonium-TOS (mito-VES), was more efficient in inducing H2O2-dependent apoptosis in mouse embryonic cytochrome c(+/+) cells than in cytochrome c(-/-) cells. Essential for execution of the apoptotic program peroxidase activation of cytochrome c by α-TOS may contribute to its known anti-cancer pharmacological activity.
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Affiliation(s)
- Naveena Yanamala
- From the Center for Free Radical and Antioxidant Health, the Departments of Environmental and Occupational Health
| | - Alexander A Kapralov
- From the Center for Free Radical and Antioxidant Health, the Departments of Environmental and Occupational Health
| | - Mirjana Djukic
- From the Center for Free Radical and Antioxidant Health, the Departments of Environmental and Occupational Health
| | - Jim Peterson
- the Departments of Environmental and Occupational Health
| | - Gaowei Mao
- From the Center for Free Radical and Antioxidant Health, the Departments of Environmental and Occupational Health
| | - Judith Klein-Seetharaman
- the Division of Metabolic and Vascular Health, Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Detcho A Stoyanovsky
- From the Center for Free Radical and Antioxidant Health, the Departments of Environmental and Occupational Health
| | - Jan Stursa
- the Biomedical Research Center, University Hospital, Hradec Kralove 569810, Czech Republic
| | - Jiri Neuzil
- the Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague 14220, Czech Republic, and the School of Medical Science, Griffith University, Southport, Queensland 4222, Australia
| | - Valerian E Kagan
- From the Center for Free Radical and Antioxidant Health, the Departments of Environmental and Occupational Health, Pharmacology and Chemical Biology, Radiation Oncology, and Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
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Stapelberg M, Zobalova R, Nguyen MN, Walker T, Stantic M, Goodwin J, Pasdar EA, Thai T, Prokopova K, Yan B, Hall S, de Pennington N, Thomas SR, Grant G, Stursa J, Bajzikova M, Meedeniya ACB, Truksa J, Ralph SJ, Ansorge O, Dong LF, Neuzil J. Indoleamine-2,3-dioxygenase elevated in tumor-initiating cells is suppressed by mitocans. Free Radic Biol Med 2014; 67:41-50. [PMID: 24145120 DOI: 10.1016/j.freeradbiomed.2013.10.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 10/02/2013] [Accepted: 10/02/2013] [Indexed: 01/07/2023]
Abstract
Tumor-initiating cells (TICs) often survive therapy and give rise to second-line tumors. We tested the plausibility of sphere cultures as models of TICs. Microarray data and microRNA data analysis confirmed the validity of spheres as models of TICs for breast and prostate cancer as well as mesothelioma cell lines. Microarray data analysis revealed the Trp pathway as the only pathway upregulated significantly in all types of studied TICs, with increased levels of indoleamine-2,3-dioxygenase-1 (IDO1), the rate-limiting enzyme of Trp metabolism along the kynurenine pathway. All types of TICs also expressed higher levels of the Trp uptake system consisting of CD98 and LAT1 with functional consequences. IDO1 expression was regulated via both transcriptional and posttranscriptional mechanisms, depending on the cancer type. Serial transplantation of TICs in mice resulted in gradually increased IDO1. Mitocans, represented by α-tocopheryl succinate and mitochondrially targeted vitamin E succinate (MitoVES), suppressed IDO1 in TICs. MitoVES suppressed IDO1 in TICs with functional mitochondrial complex II, involving transcriptional and posttranscriptional mechanisms. IDO1 increase and its suppression by VE analogues were replicated in TICs from primary human glioblastomas. Our work indicates that IDO1 is increased in TICs and that mitocans suppress the protein.
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Affiliation(s)
- Michael Stapelberg
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia.
| | - Renata Zobalova
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia; Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Maria Nga Nguyen
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Tom Walker
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia; Department of Neurosurgery, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Marina Stantic
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Jacob Goodwin
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Elham Alizadeh Pasdar
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Thuan Thai
- Centre for Vascular Research, School of Medical Sciences, University of New South Wales, Sydney, 2052 NSW, Australia
| | - Katerina Prokopova
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic; Faculty of Science, Charles University, 11000 Prague 1, Czech Republic
| | - Bing Yan
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Susan Hall
- School of Pharmacy, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | | | - Shane R Thomas
- Centre for Vascular Research, School of Medical Sciences, University of New South Wales, Sydney, 2052 NSW, Australia
| | - Gary Grant
- School of Pharmacy, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Jan Stursa
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia; Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague 160 00, Czech Republic
| | - Martina Bajzikova
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Adrian C B Meedeniya
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Jaroslav Truksa
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic
| | - Stephen J Ralph
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Olaf Ansorge
- Department of Neurosurgery, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Lan-Feng Dong
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia
| | - Jiri Neuzil
- School of Medical Science, Griffith Health Institute, Griffith University, Southport, 4222 QLD, Australia; Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic.
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Dong LF, Jameson VJA, Tilly D, Prochazka L, Rohlena J, Valis K, Truksa J, Zobalova R, Mahdavian E, Kluckova K, Stantic M, Stursa J, Freeman R, Witting PK, Norberg E, Goodwin J, Salvatore BA, Novotna J, Turanek J, Ledvina M, Hozak P, Zhivotovsky B, Coster MJ, Ralph SJ, Smith RAJ, Neuzil J. Corrigendum to: "Mitochondrial targeting of α-tocopheryl succinate enhances its pro-apoptotic efficacy: A new paradigm for effective cancer therapy" [Free Radic Biol Med. 50 (2011) 1546-1555]. Free Radic Biol Med 2013; 65:895-896. [PMID: 30184722 DOI: 10.1016/j.freeradbiomed.2013.08.164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 08/14/2013] [Indexed: 11/25/2022]
Affiliation(s)
- Lan-Feng Dong
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia.
| | | | - David Tilly
- Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, QLD, Australia
| | | | - Jakub Rohlena
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Karel Valis
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Jaroslav Truksa
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Renata Zobalova
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia; Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Elahe Mahdavian
- Department of Chemistry and Physics, Louisiana State University Shreveport, Shreveport, LA 71115, USA
| | - Katarina Kluckova
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Marina Stantic
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia
| | - Jan Stursa
- Institute of Biochemistry and Organic Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Ruth Freeman
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia
| | - Paul K Witting
- Discipline of Pathology, Bosch Research Institute, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Erik Norberg
- Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
| | - Jacob Goodwin
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia
| | - Brian A Salvatore
- Department of Chemistry and Physics, Louisiana State University Shreveport, Shreveport, LA 71115, USA
| | - Jana Novotna
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | - Miroslav Ledvina
- Institute of Biochemistry and Organic Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Pavel Hozak
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Boris Zhivotovsky
- Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
| | - Mark J Coster
- Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, QLD, Australia
| | - Stephen J Ralph
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia
| | - Robin A J Smith
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Jiri Neuzil
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia; Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Kovarova J, Bajzikova M, Vondrusova M, Stursa J, Goodwin J, Nguyen M, Zobalova R, Pesdar EA, Truksa J, Tomasetti M, Dong LF, Neuzil J. Mitochondrial targeting of α-tocopheryl succinate enhances its anti-mesothelioma efficacy. Redox Rep 2013; 19:16-25. [PMID: 24225203 DOI: 10.1179/1351000213y.0000000064] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
UNLABELLED Malignant mesothelioma (MM) is a fatal neoplastic disease with no therapeutic option. Therefore, the search for novel therapies is of paramount importance. METHODS Since mitochondrial targeting of α-tocopheryl succinate (α-TOS) by its tagging with triphenylphosphonium enhances its cytotoxic effects to cancer cells, we tested its effect on MM cells and experimental mesotheliomas. RESULTS Mitochondrially targeted vitamin E succinate (MitoVES) was more efficient in killing MM cells than α-TOS with IC₅₀ lower by up to two orders of magnitude. Mitochondrial association of MitoVES in MM cells was documented using its fluorescently tagged analogue. MitoVES caused apoptosis in MM cells by mitochondrial destabilization, resulting in the loss of mitochondrial membrane potential, generation of reactive oxygen species, and destabilization of respiratory supercomplexes. The role of the mitochondrial complex II in the activity of MitoVES was confirmed by the finding that MM cells with suppressed succinate quinone reductase were resistant to MitoVES. MitoVES suppressed mesothelioma growth in nude mice with high efficacy. DISCUSSION MitoVES is more efficient in killing MM cells and suppressing experimental mesotheliomas compared with the non-targeted α-TOS, giving it a potential clinical benefit.
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Havlik J, Petrakova V, Rehor I, Petrak V, Gulka M, Stursa J, Kucka J, Ralis J, Rendler T, Lee SY, Reuter R, Wrachtrup J, Ledvina M, Nesladek M, Cigler P. Boosting nanodiamond fluorescence: towards development of brighter probes. Nanoscale 2013; 5:3208-3211. [PMID: 23314709 DOI: 10.1039/c2nr32778c] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A novel approach for preparation of ultra-bright fluorescent nanodiamonds (fNDs) was developed and the thermal and kinetic optimum of NV center formation was identified. Combined with a new oxidation method, this approach enabled preparation of particles that were roughly one order of magnitude brighter than particles prepared with commonly used procedures.
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Affiliation(s)
- Jan Havlik
- Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2, 166 10, Prague 6, Czech Republic
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Rohlena J, Dong LF, Kluckova K, Zobalova R, Goodwin J, Tilly D, Stursa J, Pecinova A, Philimonenko A, Hozak P, Banerjee J, Ledvina M, Sen CK, Houstek J, Coster MJ, Neuzil J. Mitochondrially targeted α-tocopheryl succinate is antiangiogenic: potential benefit against tumor angiogenesis but caution against wound healing. Antioxid Redox Signal 2011; 15:2923-35. [PMID: 21902599 PMCID: PMC3201633 DOI: 10.1089/ars.2011.4192] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS A plausible strategy to reduce tumor progress is the inhibition of angiogenesis. Therefore, agents that efficiently suppress angiogenesis can be used for tumor suppression. We tested the antiangiogenic potential of a mitochondrially targeted analog of α-tocopheryl succinate (MitoVES), a compound with high propensity to induce apoptosis. RESULTS MitoVES was found to efficiently kill proliferating endothelial cells (ECs) but not contact-arrested ECs or ECs deficient in mitochondrial DNA, and suppressed angiogenesis in vitro by inducing accumulation of reactive oxygen species and induction of apoptosis in proliferating/angiogenic ECs. Resistance of arrested ECs was ascribed, at least in part, to the lower mitochondrial inner transmembrane potential compared with the proliferating ECs, thus resulting in the lower level of mitochondrial uptake of MitoVES. Shorter-chain homologs of MitoVES were less efficient in angiogenesis inhibition, thus suggesting a molecular mechanism of its activity. Finally, MitoVES was found to suppress HER2-positive breast carcinomas in a transgenic mouse as well as inhibit tumor angiogenesis. The antiangiogenic efficacy of MitoVES was corroborated by its inhibitory activity on wound healing in vivo. INNOVATION AND CONCLUSION We conclude that MitoVES, a mitochondrially targeted analog of α-tocopheryl succinate, is an efficient antiangiogenic agent of potential clinical relevance, exerting considerably higher activity than its untargeted counterpart. MitoVES may be helpful against cancer but may compromise wound healing.
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Affiliation(s)
- Jakub Rohlena
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Dong LF, Jameson VJA, Tilly D, Prochazka L, Rohlena J, Valis K, Truksa J, Zobalova R, Mahdavian E, Kluckova K, Stantic M, Stursa J, Freeman R, Witting PK, Norberg E, Goodwin J, Salvatore BA, Novotna J, Turanek J, Ledvina M, Hozak P, Zhivotovsky B, Coster MJ, Ralph SJ, Smith RAJ, Neuzil J. Mitochondrial targeting of α-tocopheryl succinate enhances its pro-apoptotic efficacy: a new paradigm for effective cancer therapy. Free Radic Biol Med 2011; 50:1546-55. [PMID: 21402148 DOI: 10.1016/j.freeradbiomed.2011.02.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 02/16/2011] [Accepted: 02/25/2011] [Indexed: 12/20/2022]
Abstract
Mitochondria are emerging as intriguing targets for anti-cancer agents. We tested here a novel approach, whereby the mitochondrially targeted delivery of anti-cancer drugs is enhanced by the addition of a triphenylphosphonium group (TPP(+)). A mitochondrially targeted analog of vitamin E succinate (MitoVES), modified by tagging the parental compound with TPP(+), induced considerably more robust apoptosis in cancer cells with a 1-2 log gain in anti-cancer activity compared to the unmodified counterpart, while maintaining selectivity for malignant cells. This is because MitoVES associates with mitochondria and causes fast generation of reactive oxygen species that then trigger mitochondria-dependent apoptosis, involving transcriptional modulation of the Bcl-2 family proteins. MitoVES proved superior in suppression of experimental tumors compared to the untargeted analog. We propose that mitochondrially targeted delivery of anti-cancer agents offers a new paradigm for increasing the efficacy of compounds with anti-cancer activity.
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Affiliation(s)
- Lan-Feng Dong
- School of Medical Science, Griffith University, Southport, QLD 4222, Australia.
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30
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Dong LF, Jameson VJA, Tilly D, Cerny J, Mahdavian E, Marín-Hernández A, Hernández-Esquivel L, Rodríguez-Enríquez S, Stursa J, Witting PK, Stantic B, Rohlena J, Truksa J, Kluckova K, Dyason JC, Ledvina M, Salvatore BA, Moreno-Sánchez R, Coster MJ, Ralph SJ, Smith RAJ, Neuzil J. Mitochondrial targeting of vitamin E succinate enhances its pro-apoptotic and anti-cancer activity via mitochondrial complex II. J Biol Chem 2011; 286:3717-28. [PMID: 21059645 PMCID: PMC3030374 DOI: 10.1074/jbc.m110.186643] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 10/28/2010] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial complex II (CII) has been recently identified as a novel target for anti-cancer drugs. Mitochondrially targeted vitamin E succinate (MitoVES) is modified so that it is preferentially localized to mitochondria, greatly enhancing its pro-apoptotic and anti-cancer activity. Using genetically manipulated cells, MitoVES caused apoptosis and generation of reactive oxygen species (ROS) in CII-proficient malignant cells but not their CII-dysfunctional counterparts. MitoVES inhibited the succinate dehydrogenase (SDH) activity of CII with IC(50) of 80 μM, whereas the electron transfer from CII to CIII was inhibited with IC(50) of 1.5 μM. The agent had no effect either on the enzymatic activity of CI or on electron transfer from CI to CIII. Over 24 h, MitoVES caused stabilization of the oxygen-dependent destruction domain of HIF1α fused to GFP, indicating promotion of the state of pseudohypoxia. Molecular modeling predicted the succinyl group anchored into the proximal CII ubiquinone (UbQ)-binding site and successively reduced interaction energies for serially shorter phytyl chain homologs of MitoVES correlated with their lower effects on apoptosis induction, ROS generation, and SDH activity. Mutation of the UbQ-binding Ser(68) within the proximal site of the CII SDHC subunit (S68A or S68L) suppressed both ROS generation and apoptosis induction by MitoVES. In vivo studies indicated that MitoVES also acts by causing pseudohypoxia in the context of tumor suppression. We propose that mitochondrial targeting of VES with an 11-carbon chain localizes the agent into an ideal position across the interface of the mitochondrial inner membrane and matrix, optimizing its biological effects as an anti-cancer drug.
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Affiliation(s)
| | | | - David Tilly
- the Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan 4111, Queensland, Australia
| | | | - Elahe Mahdavian
- the Department of Chemistry and Physics, Louisiana State University, Shreveport, Louisiana 71115
| | - Alvaro Marín-Hernández
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Luz Hernández-Esquivel
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Sara Rodríguez-Enríquez
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Jan Stursa
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague 14220, Czech Republic
| | - Paul K. Witting
- the Discipline of Pathology, Bosch Research Institute, Sydney Medical School, University of Sydney, Sydney 2006, New South Wales, Australia
| | - Bela Stantic
- Institute for Integrated and Intelligent Systems, and
| | | | | | | | - Jeffrey C. Dyason
- Institute for Glycomics, Griffith University, Southport 4222, Queensland, Australia
| | - Miroslav Ledvina
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague 14220, Czech Republic
| | - Brian A. Salvatore
- the Department of Chemistry and Physics, Louisiana State University, Shreveport, Louisiana 71115
| | - Rafael Moreno-Sánchez
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Mark J. Coster
- the Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan 4111, Queensland, Australia
| | | | - Robin A. J. Smith
- the Department of Chemistry, University of Otago, Dunedin 9016, New Zealand
| | - Jiri Neuzil
- From the School of Medical Science
- Institute for Glycomics, Griffith University, Southport 4222, Queensland, Australia
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Morgenstern A, Lebeda O, Stursa J, Bruchertseifer F, Capote R, McGinley J, Rasmussen G, Sin M, Zielinska B, Apostolidis C. Production of230U/226Th for Targeted Alpha Therapy via Proton Irradiation of231Pa. Anal Chem 2008; 80:8763-70. [DOI: 10.1021/ac801304c] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lebeda O, Jiran R, Rális J, Stursa J. A new internal target system for production of (211)At on the cyclotron U-120M. Appl Radiat Isot 2005; 63:49-53. [PMID: 15866447 DOI: 10.1016/j.apradiso.2005.02.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 02/23/2005] [Accepted: 02/25/2005] [Indexed: 11/18/2022]
Abstract
The alpha emitter (211)At is a radionuclide with good potential for use in the therapy of smaller tumours and metastases. However, limited availability of this radionuclide hinders development of this application and the research of astatine chemistry in general. In this general context we have designed and tested a new internal target system. A thin bismuth layer (3-5 microm) was evaporated onto a light target backing (7.5 g) and irradiated at 0.5-1.5 degrees angles with 29.5 MeV alpha particles beam of intensity up to 30 microA. The backing was then released from the target holder and used directly for astatine separation via dry distillation. Astatine condensed on the Teflon capillary walls was then eluted into 150-250 microl of methanol. The saturation yield was found to be ca. 400 MBq/microA, and the radionuclidic purity of (211)At acceptable for medical applications (activity ratio (210)At/(211)At<10(-3) at EOB). The overall separation yield was 65-75%.
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Affiliation(s)
- O Lebeda
- Nuclear Physics Institute of the Czech Academy of Sciences, CZ-250 68 Rez near Prague, Czech Republic.
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Stursa J, Dvorakova H, Smidrkal J, Petrickova H, Moravcova J. A novel synthesis of parent resorc[4]arene and its partial alkyl ethers. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.01.080] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Cervinka P, St'ásek J, Costa MA, Stursa J, Fiser M, Vodnanský P, Kocisová M, Veselka J, Pleskot M, Malý J. The "edge effect" after implantation of beta-emitting (55Co) stents with high initial activity. Acta Medica (Hradec Kralove) 2004; 47:37-42. [PMID: 15168880] [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: 04/29/2023]
Abstract
The aim of this study was to evaluate the incidence and the cause of "edge restenosis" after implantation of high activity 41.1 microCi +/- 1.2 microCi = 1520 kBq +/- 44 kBq, beta-emitting (55Co) stents. Proton bombarding in cyclotron has brought the radioactivity. Intravascular ultrasound (IVUS) investigation has been completed in 10 patients. The angiographies performed at 6 month revealed restenosis >50% in 5 cases (50%). The analysis of edges (5 mm distally and proximally to the last stent struts) showed no significant changes in TVV (187.3 +/- 62.60 mm3 and 176.9 +/- 53.5 mm3) but PMV increase significantly (i.e. neointimal proliferation) from 61.9 +/- 31.2 mm3 to 82.2 +/- 43.4 mm3 (p<0.04) and was the major contributor (from 66%) to lumen volume loss (125.4 +/- 40.7 mm3 and 94.7 +/- 22.2 mm3, p<0.02). In conclusion, neither statistically significant positive nor negative remodelling at the "stent edges", were present. Statistically significant increase in plaque +/- media volume (i.e. neointimal hyperplasia) and reduction in lumen volume were found. The cause of "edge restenosis" was especially (from 66%) due to increase in plaque +/- media volume (i.e. neointimal hyperplasia). Probably, main reason for "edge effect"/neointimal hyperplasia was in this trial sharp fall-off in radiation at the edges of the stents.
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Affiliation(s)
- Pavel Cervinka
- Department of Cardiology, Masaryk Hospital, Ustí nad Labem, Czech Republic.
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Abstract
3-O-Carboxymethylcoumestrol was prepared as the hapten for immunoassay by a partial alkylation of coumestrol with ethyl chloroacetate in acetone alkalized with potassium carbonate. 3-O-Ethoxycarbonylmethylcoumestrol was separated by column chromatography and finally was hydrolyzed with formic acid. 1H and 13C NMR data (APT, COSY, HMQC, and HMBC) revealed that the reaction was regioselective, as 3-O-ethoxycarboxymethylcoumestrol was the only monosubstituted derivative. The hapten was then conjugated to bovine serum albumin and used for immunization of rabbits. A radioimmunoassay (RIA) system was established based on the polyclonal antiserum and a 125I-labeled hapten-tyrosine methyl ester conjugate as the radioligand. Parameters of the RIA: sensitivity: 12 pg per tube, 50% intercept: 140 pg per tube, working range: 20-4000 pg per tube. The cross-reactivity of a panel isoflavonoid and lignan phytoestrogens was either negligible (e.g. formononetin 0.07%; biochanin A 0.06%) or not detectable at all. The major immunoreactive peak in HPLC fractions from an alfalfa extract had the same retention time as coumestrol standard and represented 94.8% of the signal. The remaining 5.2% of immunoreactivity was distributed between five minor peaks. We conclude that after the validation for particular matrices, the method will be a useful tool for analysis of coumestrol, especially in low volume and low concentration samples.
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Affiliation(s)
- Oldrich Lapcík
- Department of Chemistry of Natural Compounds, Institute of Chemical Technology, Technická 5, 166 28 Praha 6, Czech Republic.
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Kroupa VF, Cizek V, Stursa J, Svandova H. Spurious signals in direct digital frequency synthesizers due to the phase truncation. IEEE Trans Ultrason Ferroelectr Freq Control 2000; 47:1166-1172. [PMID: 18238657 DOI: 10.1109/58.869062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Direct digital frequency synthesizers (DDS or DDFS) are widely used in modern communications and measurement devices. Their advantages are small size and power consumption together with excellent frequency stability, high frequency resolution, and short switching times. The difficulties are rather low output frequencies (500 MHz at the present state of the art) and a large set of the spurious signals very often above the -80 dB level. One source of spurious signals in DDS is the use of smaller number, W, of the most significant bits (MSB) applied for the output sine wave reconstruction from all R bits stored in the accumulator. The result is a phase modulation of the output signal. The problem was first solved in a rather complicated way with the result that the level of the largest spurious signal is about -6 W dB below the carrier with an increase of 3.9 dB in some instances. A simpler solution of the problem of spurious signal level due to the phase truncation in DDS was found earlier. However, no attention was paid to the validity of the corrections suggested. In this paper we will be concerned with this problem and investigate the validity and correctness of these generally cited results and provide a simple way for finding positions, levels, and numbers of these spurious signals generated by truncation to W bits of the phase information stored in the DDS accumulator memory of R bits (W<R).
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Affiliation(s)
- V F Kroupa
- Inst. of Radio Eng. and Electron., Czechoslovak Acad. of Sci., Prague
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